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Can I start my 2000 TL without the intake manifold?
I need to be able to check the injector circuit while the car is running, and the only way I can think to do that is to start it with the intake manifold removed.
I'm currently chasing down a short somewhere - the car runs like crap - definitely misfires (P1399). When the idle drops due to misfire, the sound of something arc'ing can occasionally be heard just under the intake snorkel hose - in that big mass of thick wire loom on top of the tranny cooler, but I can't see anything arc'ing. Not sure if that's the cause of misfire or not, but definitely worrisome. I can't think of anything else that would cause a misfire - fuel pump? Fuel pressure? The fuel pump does has 240,000 miles on it....The engine has only about 95,000 miles on it.
- Changed all the coil packs and spark plugs and verified each plug connector is working with a spark tester - all good.
- Pulled the intake manifold and checked each injector connection for 12v power - all good
- Checked resistance on each injector - all good.
- Used a noid light and checked each injector connection while cranking the engine - all good
Checked the EGR power, ground, and operation - all good.
Next up is to start it and see if each cylinder spark & injector is working while it's running, but can do that only when the intake manifold is off, hence my question.
So, can I start it with the intake manifold off? I'm thinking "yes", cuz, well, it can't run any worse than it already does! LOL.
What brand coils/ spark plugs did you use and where did you find them?
Coils are Delphi GN10168 from Delphi store on Amazon.
Spark plugs are NGK ZFR5F-11 - the v-power ones, also from Amazon.
I didn't use the Iridium's because they wear out faster and performance is not really a concern of mine, just durability.
A spark tester shows a nice big fat spark on each cylinder, so everything there seems to be working.
I'm starting to think it's something other than spark or injectors, like maybe bad gas.
Think again, there will be no throttle control. Basically like having engine at Wide open Throttle.
I thought of that, but since all the intake air is not passing through the MAF sensor which meters the amount of fuel (since that's in the intake snorkel which is disconnected from the manifold) the engine will think very little air (if any) is moving. I presumed the car would barely run, if at all.
But I could be wrong, hence my hesitation to try it.
Coils are Delphi GN10168 from Delphi store on Amazon.
Spark plugs are NGK ZFR5F-11 - the v-power ones, also from Amazon.
I didn't use the Iridium's because they wear out faster and performance is not really a concern of mine, just durability.
A spark tester shows a nice big fat spark on each cylinder, so everything there seems to be working.
I'm starting to think it's something other than spark or injectors, like maybe bad gas.
both the Denso and NGK brand are only a few bucks more on Rockauto...
bad gas will give you a problem that occurs everywhere...do you still have your old coils? any difference between those and your new coils?
You'd need some really high voltage to be able to hear arcing...are you sure it's not some vacuum or the the engine mount solenoid releasing air as your idle fluctuates? if you have a vacuum in the engine mount line you could have some strange idle...did you clear the code and does the misfire code return?
both the Denso and NGK brand are only a few bucks more on Rockauto...
bad gas will give you a problem that occurs everywhere...do you still have your old coils? any difference between those and your new coils?
You'd need some really high voltage to be able to hear arcing...are you sure it's not some vacuum or the the engine mount solenoid releasing air as your idle fluctuates? if you have a vacuum in the engine mount line you could have some strange idle...did you clear the code and does the misfire code return?
Haven't re-tried the old coils, but the engine was misfiring when they were installed before I started this whole thing...
I bought Delphi coils mentioned above, which I believe was OEM.
I still have my old coils. Cylinders were misfiring previously, which is what led me to purchase new coils. I replaced all of them just to rule out any imbalanced resistance detected by the PCM.
Ya, it definitely sounds like arcing. It's not consistent, or even periodic. Just every now-and-then, when the idle gets low. It's a definite rhythmic "pop", like an arc when a certain cylinder fires.
When I was driving home from Home Depot (before this whole thing started), I noticed the CEL come on and the engine started missing.
I kept driving, with about 10 miles to get home.
The more I drove, the more it started arcing....until it eventually sounded like popcorn from under my hood a few miles later. Almost had to floor it to keep it running.
I slowed to about 20mph, but kept driving - knowing I'd never get the car moving again if I stopped. Ran a stop-sign just to make it home. The arcing finally subsided as I neared home.
The car made it home, but was obviously severely injured and barely running, likely running on just 2 cylinders. Testing by removing the coil taps on all the rear cylinders as well as one on the front yielded no change in engine RPM. I assumed 4 dead coils or spark plugs.
That's when I pulled the coils and spark plugs (which were severely worn) and replaced everything on all 6 cylinders, and verified everything with a spark tester.
Removed the intake manifold and tested each injector with a noid light while cranking - all good.
Restarting the car now yields a very rough idle with the same symptoms, a P1399, and a struggle to keep the car running even though all sparks and injectors appear to be working when diagnosed. Of course I haven't started it without the intake manifold - yet. I'm tempted to try it....
I'm starting to think this isn't ignition related, but something else, but I can't figure out why it was shorting out so badly on my drive home....
Randy, I would step back for a moment. Make sure the noise you are hearing is actual arcing, as stated (whitetiger5) it usually takes a high voltage or high amp spark to make a noise you would hear over the engine. Could the snapping noise you hear be the Vapor Canister purge valve that is located on the driver side, near the firewall at the top. This valve can make a snapping noise that sounds like arcing. It can also cause the following:
Engine misfire or poor engine performance
Noticeable fuel odor
Premature wear of spark plugs or damaged engine gaskets
Randy, I would step back for a moment. Make sure the noise you are hearing is actual arcing, as stated (whitetiger5) it usually takes a high voltage or high amp spark to make a noise you would hear over the engine. Could the snapping noise you hear be the Vapor Canister purge valve that is located on the driver side, near the firewall at the top.
Hmm - that is a VERY good suggestion! It is in the vicinity of where I hear the arcing/snapping, although it's a bit high on the firewall.
Regardless, I removed the vapor canister purge valve and tested the input of the connector (not sure how to test the switched ground ECU signal)
I also bench tested the operation of the solenoid, even to the point of blowing through it when it was open - lol!
It was all good.
I then thought I'd bench check the mechanical operation of my injectors since I was in so deep, and, well, I really screwed the pooch on this-
I ended up breaking the plastic tips (I think they call it the "pintle cap") on two of them, and since it appears that isn't replaceable on these injectors, I get to wait 2 days for new ones.
Needless to say, the injectors were all good.
( : sigh : )
Randy, A word of caution on the fuel injectors, stay away from any of the cheap ones. They will cause you nothing but problems. This is one of the items I highly recommend you buy the OEMs, If you must, due to time and money, the ones from SMP sometimes work Ok. There are several parts that OEM is best these and Idle Air Control Valve is another. And yes I have found a bad (cracked) pintel cap and tried several cheap fuel injectors. Really don't bother!
I have used the battery or a 12v power supply to power up the solenoid and used the ground line to pulse the solenoid.
You'd need some really high voltage to be able to hear arcing...are you sure it's not some vacuum or the the engine mount solenoid releasing air as your idle fluctuates? if you have a vacuum in the engine mount line you could have some strange idle...did you clear the code and does the misfire code return?
This is true, high voltage or high amperage would be needed to even make a spark loud enough to hear. It makes no sense to me - a 12v line wouldn't produce an arc loud enough, but I swear I hear an arc. Occasionally. But the car still runs like crap even when it's not arcing. I can only assume it's shorting when it's not arcing. Either that, or I'm chasing the wrong rabbit.
It looks like I can post avi and/or wmv video, I might try that when I can get the car back to a semi-running state.
No. There doesn't appear to be any difference between my old coils and my new coils. The new ones register a nice fat spark on my spark tester for every cylinder. While these apparently aren't OEM, they seem to be working fine.
Yes. I cleared the code each time I tested. However, it's been a few days since I tested it - see above posts for my recent f- ups (*ahem* "difficulties").
Randy,
You can go through each of the wire bundles looking for melted wire casings and lightly tug on the wires near the ends. I would look at wire near brackets and hot engine pieces. Replaced my throttle body today with a brand new unit (expensive but ..) car runs and idles great. However I noticed the wire bundle for the front 3 coils was on the wrong side of the breather pipe which gets hot. Had to disconnect the coils and reroute the cable to avoid problems. Could be something similar.
Welp, got the new injectors and put the whole thing back together - to no avail. It still missing badly and arcing occasionally. I verified all plugs, coils, and injectors are good, yet I can disconnect the entire back bank of coils simultaneously and it doesn't change the how the engine is running if/when I can get the engine to stabilize at a certain RPM (not easy to do). It's like the entire back bank of cylinders isn't working, but only when everything is installed. Removing the coils and testing each with a spark tester (grounded to the top of the engine) shows a big fat spark on each.
I managed to grab some video with audio:
missing.mov = the definite sound of misfiring from the tailpipe.
cylinder.mov = disconnecting 2 of the 3 back coils simultaneously, with no change in engine RPM.
arcing.mov = a quick video of the arcing sound. Yes you can hear the rhythmic clicking of the purge solenoid in the background, but the (louder) asynchronous clicking is the arcing sound.
Since it requires high voltage/amperage to create an arc, could this be a grounding issue? It's almost like the the detonation spark is taking place somewhere outside the engine and not between the spark plug gap, but I'm not sure that makes any sense.
( :sigh: )
I have watched the 3 videos and I am going to throw out random thoughts. Hopefully others will also chime in.
The Cylinder video shows you removing and attaching the input to one coil at a time with no discernable change in RPM (normal correct way to find bad coil). This can mean that coils you bought are not firing all the time but only sometimes. Did you try removing more than one coil input at a time?
Since your idle is poor, you should have come across a coil wire that once you removed it caused the car to stall. Take and swap this coil with one that appears to have no effect on the idle. The car may or may not now be able to idle. If the car does not idle; this would tell me the coil that appeared to have no effect is bad.
If the car does idle then disconnect the coil that first appeared not to have an effect. If there is no change in the idle that coil is bad. If you disconnect the one that caused the car to stop idling (from above) and it now has no effect on the idle, the control signal to that coil connector has a problem. Either a bad wire or bad computer input.
The above should determine if you have a bank with a problem or just some bad coils/spark plugs.
Right now, the Acurazine webpage keeps resetting on me. So I am writing this in word to cut and paste as quickly as possible. I remember you replaced the spark plugs. Just to make sure I hope you used NGK PZFR5F-11 or Denso PKJ16CR-L11 with the gaps .039 - .043 inches and that you didn’t just pull from the box but you physically measured them out of the box before installing. People think that all plugs are pre-gapped but that is not always the case.
it doesn't sound like arcing. it sounds like mechanical ticking..could be many things, can you use an automotive stethoscope to pinpoint it a bit better?
Your timing belt is in good condition? when was the last time you had your valve clearances adjusted?
about the sound of your exhaust...do you have more than one cylinder misfiring right now? the idle sounds very poor; not indicative of one cylinder doing it's job but many...that's why I asked about the timing belt.
The Cylinder video shows you removing and attaching the input to one coil at a time with no discernable change in RPM (normal correct way to find bad coil). This can mean that coils you bought are not firing all the time but only sometimes. Did you try removing more than one coil input at a time?
Actually, I disconnected the first coil, then reattached it, then realized I wanted to show more than one coil disconnected at the same time, so I pulled it back off (unfortunately, the camera wavered right when I did that). Then I moved to the next coil and disconnected that, so in that video I had two coils disconnected at the same time after I removed the second coil connector. One time previously I had disconnected all 3 coils simultaneously on the back bank and the RPMs didn't change. Of course it's really difficult to get the car to stay idling like it was in the video, 9 times out of 10 it simply stalls.
OK - just made a couple more videos.
spark.mov - showing a good spark from one of the back cylinders. From previous testing, all 3 cylinders in the back produce good sparks with the tester.
allback3.mov - showing all 3 coil connectors on the back bank disconnected at the same time. Idle doesn't change when they're all reconnected. (sorry for the poor camera work - why couldn't this problem happen with the front bank instead? lol). I then disconnect all 3 again.
I did all that coil and plug swapping diagnosis, including swapping known good coils with some in the back, swapping in my old coils, changing spark plugs around etc etc etc. No matter what I did, the coils work fine in the spark tester, but (apparently) not when connected to the spark plugs, regardless of what spark plugs are installed. It's almost like the back engine bank isn't grounded, but that makes no sense cuz the entire engine is grounded or the front bank wouldn't work either.
I don't think it's coils or plugs or injectors, and it looks like my ECU is working, since the spark.mov video shows a functioning spark. The only difference is the spark tester is grounded through a different mechanism (wire) than the spark plugs.
it doesn't sound like arcing. it sounds like mechanical ticking..could be many things, can you use an automotive stethoscope to pinpoint it a bit better?
Your timing belt is in good condition? when was the last time you had your valve clearances adjusted?
about the sound of your exhaust...do you have more than one cylinder misfiring right now? the idle sounds very poor; not indicative of one cylinder doing it's job but many...that's why I asked about the timing belt.
Ya, I could use a stethoscope, but the arcing/ticking isn't always consistent. Like it will occur for a few minutes, then disappear. When this first occurred, that "ticking/arcing" was really persistent for about 30 seconds and the car would barely run - I wonder if I burned something out or really hosed something. I was still about 10 miles from home when everything went south.
Timing belt was replaced when I replaced the engine - about 20,000 miles ago. Engine had 79,000 on it originally.
I have never adjusted the valve clearance. Would this cause a sudden misfire on multiple cylinders? I'm going to look into this a bit more.
Yes, there is more than one cylinder misfiring - you can see from a video I just uploaded that all 3 cylinders on the back bank are not firing when the coils are installed on the plugs. When I remove them to test them, they fire just fine.
Thanks much for the suggestions! I appreciate it.
--Randy
I will admit this is weird. Since you showed the spark from one of the back bank coils there couldn't be a problem with the harness as long as twisting of the harness to lay it across the intake didn't allow a broken connection to be made. If we assume that the coils are firing when connected to the plugs then what could it be. Being that this is not being straight forward or the information we are seeing is misleading how should troubleshooting continue. Your disconnecting the rear bank of coils with no change is unbelievable, I never thought you would be able to get the car started and stay running. So how is this for a theory, that the coils or plugs are firing but not with enough power or at the correct frequency. If it was me, besides using a lot of choice words, I would buy a Denso coil from Rockauto and swap it with one in the rear.
Another thing to try is take you old coils and check the spark from them and swap in the best one or two or three. Do that before spending more money on another. If the idle becomes better then we are onto something,
As you can see by the schematic below the plugs are the ground for each individual spark plug. There is a control ground from the ICM and a control signal that is from the PCM. The power is coming through the ignition switch and a 15amp fuse. You might want to check the 15amp fuse for resistance. Using an Ohmmeter (or DVM with ohm setting) make sure it measures 0 ohms, don't just do a continuity test, as I have seen fuses become resistant and cause very hard to find problems. I can explain if this is something new to you.
I see from your posts you are concerned about grounding to the engine. Check the main ground down below the starter make sure the wires are not splayed out and you don't see any corrosion. You can also add a wire from the battery ground to a the engine anywhere you can reach and have a bolt. I add several additional battery grounds around my engines. You can buy an extra battery ground cable with lugs on them from any auto supply store or Walmart.
I would be frustrated (been there before) if I was dealing with this on my car. I hope we are making it better not worse. Hang in there. There are many smart people here.
Randy,
Another couple of things. I assume you have to have all the coils plugged in to start the car but after its started you can pull the coil wires. This would indicate to me that while the coils are working they are working correctly.
You should pull the plugs and check for fouling. If the coils aren't firing all the time those cylinders would be flooded with gas. You may need to clean the plugs, if they are soaked let them dry out.
Now for some even more far fetched comments, before this started did you do any work on the car? After this started did you clean out anything where you were using a rag that you might have left inside (I have seen it happen)?
You used a noid light to test the fuel injectors, but did you pull any injectors to verify the spray pattern? I have a very cheap fuel injector cleaner/tester I purchased from ebay. Not great, very basic but useable
.https://www.ebay.com/itm/274672495890
Ok! - getting back into this after a few life-changing "events" of the last couple days (can anyone say "high-tech layoffs"? - lol)
Suddenly I have much more time (and incentive) to work on this!
Did a lot of research (mostly sitting on my ass drinking coffee and Youtubing videos) and since it affects only a single bank of my engine, I reasoned it must be related to whatever those cylinders have in common. Why the hell would one entire bank of cylinders suddenly "stop" working?
Oh sure, it sounds fine when I rev the engine to 2000rpm, but as soon as it idles, it barely runs. And it idles only when the engine is cold. The more it warms, the worse it idles.
After earning my black-belt in Google-fu today, I found a guy who discovered his semi-identical symptoms were caused because of a "clogged fuel rail". That sounds highly unlikely, but there is a fuel rail shared by the back cylinder bank.
I might rip the intake manifold off and look into this.....
I will admit this is weird. Since you showed the spark from one of the back bank coils there couldn't be a problem with the harness as long as twisting of the harness to lay it across the intake didn't allow a broken connection to be made. If we assume that the coils are firing when connected to the plugs then what could it be. Being that this is not being straight forward or the information we are seeing is misleading how should troubleshooting continue. Your disconnecting the rear bank of coils with no change is unbelievable, I never thought you would be able to get the car started and stay running. So how is this for a theory, that the coils or plugs are firing but not with enough power or at the correct frequency.
Ya, I really don't think it's spark/coil related. That's the first (and easiest) to check, so I spent hours moving spark plugs and coils around (both new and old), looking for any sort of "signature".
Didn't matter what I did - the back bank didn't work under load, only when viewed with a tester did it work properly, regardless of what coils or plugs were installed where.
Kind of a "reverse Observer Effect" for you science nerds out there.
Originally Posted by Jon M
As you can see by the schematic below the plugs are the ground for each individual spark plug. There is a control ground from the ICM and a control signal that is from the PCM. The power is coming through the ignition switch and a 15amp fuse. You might want to check the 15amp fuse for resistance. Using an Ohmmeter (or DVM with ohm setting) make sure it measures 0 ohms, don't just do a continuity test, as I have seen fuses become resistant and cause very hard to find problems.
Pulled the fuse indicated in your diagram and checked for Ohms - all's good there. Thanks for the suggestion!
Originally Posted by Jon M
You can also add a wire from the battery ground to a the engine anywhere you can reach and have a bolt. I add several additional battery grounds around my engines
Thought of that, and did it. Ran a 12-guage wire from various points around the back cylinder bank straight to the NEG battery post.
No change.
I think I'm going to investigate fuel delivery to the rear bank. Might have to pull the rear fuel rail and injectors. This seems highly unlikely to be the problem, but bad fuel suddenly clogging all 3 rear injectors (why wouldn't it clog some in the front?) might be a possibility....
The "clicking/arcing" sound still bothers me. It happens only when the engine is cold-ish. It stops after about 10 minutes.
This video has the same sound at around time mark 1:45. But my engine isn't surging like that, it's just barely idling. Notice it happens only when his idle drops way low. My idle is low all the time, so it happens continuously for about 5 minutes after starting. Then the engine doesn't idle by itself anymore - I assuming because it's warmed up sufficiently and the Air/Fuel mixture is changing....
Randy, a partial blockage would fit the symptoms. Unfortunately you will need to pull the upper intake manifold. I normally replace the upper intake manifold gaskets when I do that. Anyway, If you have a fuel pressure gauge and the fitting you should be able to tell if the fuel pressure is bad. If it is partially blocked I would think that the fuel pressure would be too high. Keep us informed this is a good one to understand. With your answers from above I think you are a high percentage track as the rails are the only thing that is common in a single bank (besides the electrical harness).
Hmm.
The more I test this, the more the misfires seem random, and not limited to just the back bank. I can't do the test where you pull each coil to see if the RPMs drop because the RPMs are so low anyway. Having someone keep the RPMs higher usually results in no change in RPMs regardless of which coil I disable. And each coil registers a spark with a spark tester. It just seems like the misfiring is random. The misfiring is really bad at low RPMs and gets worse as the car warms up. It's also less noticeable at higher RPMs (seems like misfiring would be less noticeable at higher RPMs no matter what the cause was..)
Running the car for an extended period of time really pumps out a lot of unburned fuel because it really starts to stink. I can surmise that all my injectors are working if there's lots of unburned fuel. Removing the top cover of the intake manifold showed lots of oil and fuel deposited there - which I can assume is being returned through the EGR? Why would there be any oil in there?
Then it hit me - I wonder if a failing alternator could be causing all this misfiring. The alternator is the original one with over 240,000 miles on it, but when I test the alternator output voltage, it registers a good 14 volts.
Are there other ways an alternator can cause misfiring even though it is (apparently) outputting good voltage?
Can we assume that there wasn't a problem with the fuel rail(s)?
If the alternator is putting out 14v it sounds ok. You can start the car and disconnect the battery. If it still idles it is good. I would guess that if the diode package is going bad the output would start to look more like a sine wave and you would be able to read a lot of AC voltage. The AC voltage shouldn't exceed 100mv AC. Although I imagine that depends on the model alternator.
The extra gas is either from being fed too much gas to start or the correct amount is not being burned. You have a few ways to test,
Test fuel pressure, look at flow rate (see manual).
Check timing belt, timing probably jumping around due to misfires.(As suggested by Whitetiger5)
Get new coils - DENSO (Thoiboi). I know you see spark and they are new. I have bought new parts that were bad and it causes all kinds of problems because you think they are working .I once put in 3 fuel filters, the first 2 (OEM) failed (under drive load they leaked fuel back into the tank) . Drove me nuts took me weeks to figure it out and develop a test setup to prove it.
I was wondering if you did a compression test on the cylinders? A bad head gasket would be something that affects the rear cylinders. A compression test would show if that is an issue.
I was wondering if you did a compression test on the cylinders? A bad head gasket would be something that affects the rear cylinders. A compression test would show if that is an issue.
I did not. And I should - that crossed my mind.
I did check my oil and coolant for evidence of this and have seen no contamination, but that is purely from visual observation.
And I don't have a cylinder compression guage. But, hey! OReilly has one I can "borrow", like I did the noid lights!
Hmm. Will definitely look into this using their "rental tools" in another couple of weeks.
I'm in the midst of helping my son to relocate to his first "real" job out-of-state, so have had to shelve this work for the time being.
Plus it's colder than crap in Colorado, and dammit!! my hands get cold!!
Lol!
I think I got it. Discussed this with neighbor who is a mechanic. Thinking of this differently the computer is controlling the timing, the injectors and the spark. Looking at in my old fashioned terms it is acting like a distributor. The camshaft sensor is like the points. It is triggering the firing. If the points are closed there is no spark if the points are open it will keep firing. The problem is probably the cam shaft sensor. Part number 37840-P8A-305 which replaced 37840-P8A-A01. We think the camshaft sensor is open and the computer is trying to adjust by all means possible. I know this means taking a bunch of stuff apart (I have done it before) but I think the odds of this solving your problem is high. If I was going to go through replacing the camshaft sensor I would be doing the whole timing belt system. Belts, sensors, pulleys, engine mount, but that is me.
Jon
What Jon M is saying sounds very plausible. I've personally never heard of the cam sensors failing, but then again, I've never seen a problem quite like this one. Funny thing is that on the 6 speed that I took apart, the cam sensor's plug & wire loom started crumbling apart. But the auto's was perfectly fine. In fact, the multiple J series auto engines I have taken apart, the cam sensors were always in relatively good condition. It's worth a shot to check out.
But I'm mainly chiming in because if all else fails, and you can't figure it out, I'd recommend trying a different ECU. This is also a longshot, but the auto ECUs seem to have a mind of their own at times. When I bought my CL, after about a month of driving it, a CEL popped up. But there were no codes stored. It refused to go away no matter. Turns out the ECU was actually bad, even though the car drove fine? Then with the new ECU, driving in auto mode, it was randomly shifting late/early sometimes, including shifting into neutral and then back to the same gear, even though I was staying at the same speed. I had weird electrical issues with the gauge cluster momentarily turning off and back on while driving, which I have a video of. It's not like my wire harness magically went bad from being untouched. I've had a lot of other 'ghost' issues that came and went completely randomly. It's been really weird honestly, but I've just lived with it. Maybe it's my car giving me an attitude because I red line her so much.
The ECUs on these cars seem to be a bit finicky, and worth giving a try when you've tried everything. I have spare auto ECUs specifically so I can test these sort of things out when trying to diagnose issues. Now I just need a spare 6 speed ECU for testing purposes..
Last edited by Thefireball; 02-18-2023 at 11:18 PM.
You are completely correct and I agree that it could be the ECU. It is the controlling factor. Hopefully though RTH's problem is not as subtle as yours. I am thinking that that area of the ECU is still good and sensor is just feeding it bad data. The problem with troubleshooting an ECU is having a known good one to compare, It may not be the sensor itself but a wire that has parted. On an 89 Volvo we have I once found the entire wire covering completely gone, Apparently there was some foam insulation that the wires went through and after 25 years the chemical interaction between the two caused the wire covering to dissolve. It was completely shorted out but the copper was also corroding and near parting.
Amazing how much knowledge that is floating around on these forums. Hopefully we can all keep helping each other out, I know the people here have helped me isolate problems before.
You are completely correct and I agree that it could be the ECU. It is the controlling factor. Hopefully though RTH's problem is not as subtle as yours. I am thinking that that area of the ECU is still good and sensor is just feeding it bad data. The problem with troubleshooting an ECU is having a known good one to compare, It may not be the sensor itself but a wire that has parted. On an 89 Volvo we have I once found the entire wire covering completely gone, Apparently there was some foam insulation that the wires went through and after 25 years the chemical interaction between the two caused the wire covering to dissolve. It was completely shorted out but the copper was also corroding and near parting.
Amazing how much knowledge that is floating around on these forums. Hopefully we can all keep helping each other out, I know the people here have helped me isolate problems before.
Y'know, the more I think about, the more you might be right. The wire for the front cam sensor is down below & behind the steering pump. You know what else is in that area? The knock sensor wire, which is notorious for going bad.
Everyone jumps on the band wagon of "a mouse got in there and chewed the wire", and while I don't doubt that it can & does happen, in my experience of trying to pull a knock sensor off of of multiple different junkyard cars, this isn't the case. Each time I tried, the knock sensor's plastic housing for the plastic always broke off. It actually broke off on this 6 speed CL engine recently. This area is right in the middle of the engine, so it's dealing with a lot of heat, and a lot of heat cycling. It's only a matter of time before the wire & knock sensor become brittle & break.
The wire for the cam sensor plug isn't exactly in the middle of the engine being exposed to the same sort of treatment, but it is in the general vicinity. It is likely that the wire could have been damaged, either from heat, or past maintenance of some one messing with the steering pump and pinching the wire.
I am very familiar with the knock sensor problem. Found 1/2 of mine rolling around at the end of the wire, the body separated where the plastic is bonded to the metal.
Broken Knock sensor 2002 TLs
I hope that RTH can get his issue fixed (and stay warm). It is interesting trying to troubleshoot someone's problem without seeing the vehicle. The odds of being correct are lower and many people don't comment, I think some people are afraid of being wrong but they shouldn't let that stop them. Sometimes a wrong suggestion leads to the correct solution.
I am interested in seeing the results from RTH's efforts.
I am very familiar with the knock sensor problem. Found 1/2 of mine rolling around at the end of the wire, the body separated where the plastic is bonded to the metal.
Broken Knock sensor 2002 TLs
I hope that RTH can get his issue fixed (and stay warm). It is interesting trying to troubleshoot someone's problem without seeing the vehicle. The odds of being correct are lower and many people don't comment, I think some people are afraid of being wrong but they shouldn't let that stop them. Sometimes a wrong suggestion leads to the correct solution.
I am interested in seeing the results from RTH's efforts.
Yeah, that picture you showed, that's exactly what I was talking about. I agree with everything you said. Been a couple of times I've seen issues, but I wait & lurk before I throw out any suggestions. That's what I did with this thread. When it comes to issues like this, the problem can be that everyone gives a different solution, causing the person to just resort to a 'shotgun' approach. Just buying a bunch of unneeded new parts that don't even fix the issue, and that adds up in money quickly. It can be discouraging when you spend a lot of money, only to still be left with the same issue.
It definitely helps to have someone in person look at your car.
I know what you mean. I have sometimes been hesitant to suggestion something because I don't want to lead someone to spending money but as they are with the car it really is up to them. I know some people have little experience with working on a car and some have much more than I do, I hope that help lead them to a solution. I know I have replaced parts that were not the problem. I do like to respond though to let people know someone has seen their request for help. I also replace parts that I know are good at the moment but if I have to remove some to get to something else or if replacing leads me to being able to easily replace them with the vehicle apart I will do that when I am already there. It does wind up costing more in parts but since I am doing it myself I feel it is cheaper than doing it again or maybe having to have someone else fix it. Such as my suggestion to RTH to replace the timing belt etc. if he is going to replace the camshaft sensor. As you know he will need to take a lot of items apart, I think it is probably about 3/5 the work of doing the timing belt.
01-23-2023, 12:16 AM
