Thirstyturtle

I know there are several posts of this issue but it seems like one or multiple coilpacks is always the answer so I'm seeking additional insight.

2002 TL, 220,000 miles
Car has thrown intermittent P030x misfire codes for the last year, no symptoms aside from CEL so I've always cleared and moved on. Over the last few months, it occasionally idles strange sometimes when in "Drive" but with the car stopped (holding brake). It drops down almost to the point of stalling, then rises back up to proper idle RPM, but never stalled. This week the CEL came on, no symptoms. Yesterday my wife drove to the store, got in to leave and after cranking it, the idle was dropping almost to the point of stalling, then coming back up, after a few times it did stall. She cranked it up again and it stalled right back out. Finally she cranked it and immediately put it in drive and drove home without issue.

I pulled all the codes indicated in subject (P0300-P0306 & P0399). I checked the coilpacks by unplugging each with car running and each one seems to be fine because the idle got rough everytime I unplugged one.

So are there any suggestions of what could be wrong? The idling issue is very inconsistent, it hasn't happened again since yesterday morning and it's been driven several times since. No recent work done, last maintenance was oil change 2k miles ago and timing belt 10k ago.

Thanks!

Nicks2001tl

Typically when a car throws codes a P number shows up that tells you what and where the problem is. In this case the codes are showing random misfires which is vague at best.


You can buy one coil and test all the coils with that one. When done reset the check engine light by pulling the clock fuse.


Also, when was the last time you changed the spark plugs?

Thirstyturtle

1) I have a new coil...how do I test the coils using it?
2) If I have a code-puller can I just reset the CEL with that or do I need to reset the ECU by pulling the clock fuse?

Bought this car from my friend when it had 205k miles. His dad bought it new and took it to the dealership always for everything. I have a 2" thick folder of receipts and invoices for everything that's ever been done to it. It seems insane that the plugs would never have been changed but as far as I can tell, I have no record of them being changed. So whether or not that's the problem (I'm sure it's at least a contributing factor), I'll be changing those ASAP.

Thanks!

Nicks2001tl

You might want to change the plugs if the folder you got didn't mention the last time they were changed. A set of NGK iridiums is about 45 bucks. 1 coil is about the same. Reset the cel by doing the clock fuse. Not sure if your scanner will do it.

Hopefully its as easy as changing the plugs or even just one coil.

Thirstyturtle

My scanner can clear codes.

I'll change the plugs regardless but how do I isolate a coil pack? My understanding was to unplug each and if the idle doesn't change, that's the bad coil. But you seem to suggest using the new good coil to test the bad ones. Do I switch out each one with the new coil until the code stops reappearing?

666wokker

Check the EGR system, it could be totally blocked, with that mileage if it was never cleaned, could very well be the issue

3.2TLc

Yeah, do as 666Wokker advised. Our TL's are very prone to having the EGR passageways clogged.

There are many things which can cause the "random" misfires and symptoms which you described. Try running some fuel system cleaner (*Seafoam*) with the next tankful of high octane premium gas to help clean any restricted fuel injectors. Clean the TB intake, IAC valve while doing the EGR system. Check for any vac leaks, make sure that the coolant is topped off in the rad, inspect the electrical connections and grounds.

After checking all this stuff.....if the issue persists, install new NGK plugs and reset the CEL. Then, if all else fails then try testing for a bad coil. When was the last T-belt service and valve adjustment performed ?

Thirstyturtle

Since it appears the plugs are original, I'll inspect and almost certainly replace those this weekend.

The last t-belt job was done ~10k miles ago at around 210k miles. To my knowledge, no valve adjustment was performed. However, the shop that did the work is a VERY highly reviewed Acura/Honda only shop and they were great to deal with, if valve adjustment is a standard thing to do with the the t-belt, I bet it was done.

I'll be pulling the top cover this weekend and inspecting the EGR ports, presumably cleaning them, and ensuring that the gasket is installed correctly, along with replacing the plugs.

I have a can of seafoam sitting in the garage, I'll run some through the vac lines and fuel tank this weekend.

Thanks for all the help, still trying to find out how to isolate the bad coil since apparently none have completely failed.

Nicks2001tl

Leave the coils for last. You have been testing them correctly. Do everything you and everyone mentioned and then reset the cel.


When done give us a heads up as to what you came up with.

Thirstyturtle

I will absolutely let everyone know what I do and what eventually corrects the problem. I hate when I find a thread where someone has the same symptoms as me but never reports back how they fixed it!

TLer trash

In my experience, it's pretty rare for the average owner to get the valves adjusted with the timing belt even though it's called for. We usually recommend adjustment when the misfiring starts. Typically about 150k miles or more.

Thirstyturtle

I assume this is something that a professional needs to do? Not a simple DIYer?

3.2TLc

There are previous threads on how to adjust the valves.
It may not be a "simple DIY" .....depends on one's mechanical abilities.

TLer trash

^^Good answer. I am constantly amazed at what diy'ers can do that even trained professionals struggle with. Read up, and if it doesn't sound overwhelming try it. Are you $300+- motivated? It's not the easiest valve adj. to do as your first.

ErickUa5

Have you checked for carbon track on the boot of the coil pack?

closetprisoner

Does your hard start/stall/misfire only happen after it at operating temperature? where you would shut it off for like 10-15 mins then try to start?

Once the motor is cool or in the morning does it start with no problem?

Thirstyturtle

I haven't yet removed any coil packs. However, when I changed the plugs tomorrow, I'll inspect each coil pack end. From what I've read, signs of trouble include dark blackening on the end and now thanks to you I know to look for a carbon track.

Any other tips one what a faulty coil pack might look like?

So far, yes. The start and then stall only happened once (well twice but right in a row) and that was after my wife drove 15 minutes to the grocery store, shopped for 15 minutes or so, and the cranked it back up.

Cranking, in my opinion, has always been quite long in this car. It's always started, even when the temperatures were below 20 but no matter the temperature it turns over for 1-2 seconds consistently. I'm hoping new spark plugs fix that.

3.2TLc

Assuming that the dealership did everything by the book, the plugs definitely should have been replaced. They are usually replaced with the T-belt service.

Review the documented receipts again. Talk to your friend, his father and the dealership where the PM was performed. The service manager could pull up any work previously done there on the car. Give us a chronological list of the maintenance which was documented.

Thirstyturtle

Well I agree it should have been done but when I got the car I went through the entire folder, line item by line item (took like 3 hours) and wrote down anything of significance. I didn't document every oil change or tire rotation but any actual mechanical work I made a note of. I reviewed that summary three times and didn't find any mention of spark plugs, so I'm thinking they're original. When I had the t-belt replaced a few months back (not by a dealership) they did not replace spark plugs.

76,000 Miles: Replaced Front Motor Mount
93,000 Miles: Differential Oil Changed, Automatic Transmission Flush
94,000 Miles: Transmission Recall (Oil Jet Kit)
100,500 Miles: Automatic Transmission Flush
114,000 Miles: Replaced Timing Belt, Water Pump, External Belts, Engine Coolant
136,000 Miles: Wheel Alignment
146,800 Miles: Driver's Side Headlight Bulb Replaced
150,564 Miles: Front Brake Pads Replaced, Resurfaced Rotors, Automatic Transmission Flush
167,000 Miles: Replaced Passenger Headlight Assembly and Bulb
174,000 Miles: New Rotors
178,000 Miles: Replaced Front Lower and Right Upper Engine Mounts
179,000 Miles: New Hood Struts, noted Transmission Hard Downshifting
187,000 Miles: Oil Changed, noted Oil Leak at Oil Pump (Recommend fixing with next Timing Belt), Headlamp Restoration
196,600 Miles: New Front Brake Pads, Resurfaced Rotors, Oil Changed
199,300 Miles: Catalytic Converter Replaced
202,000 Miles: Drive Belt Tensioner Replaced
205,000 Miles: HVAC Blower Motor Harness Replaced
207,000 Miles: Oil Changed
211,500 Miles: Timing Belt, Water Pump, crankshaft seal, camshaft seal, Tensioner, Coolant, both drive Belts, all o-rings, Oil Pump seals, spool valve and oil filter housing o-rings, Oil pan gasket.
212,000: Battery Replaced
214,600: Oil and filter replaced, headlights polished

3.2TLc

Hmmm, well it's easy enough to pull a plug and check it's condition. That'll tell the story !

Replacing the spark plugs is a simple "DIY". It's always a good place to start if in doubt.

closetprisoner

i have the same condition as you with all misfire code and p01399.. my problem is HOT start, so after engine is driven.. say go to the store then restart within 15-20 mins or so, then it would stall and misfired.

I changed out the plug and few coils.. but nothing.. took me two months to test it slowly, cuz don't wana pour $ into it..

Finally come to FPR that if i pull the vacuum hose and plug it, it restart fine at operating temp.. so i plug it and drive around for few days and it did not have any misfire/stall since.. end up replace with a used FPR..

Bought a new FPR too but somehow the new one still give me the same symptom, but the used one work for whatever reason.. so i just use the used one. Try this see if it works for you.

closetprisoner

FWIW... during the process of narrowing it down, I did the following:

re-solder main relay (1st thing i did.. no cost)
Change sparkplug (2nd thing.. cheapest)
swap out some coils (got this for free from friend)
Check fuel pressure (within specs)
Check EGR and carbon cleaning and re-adjust valves, again (all these were done few months back)

Even after all the above was done.. still misfired/stall..

UNTIL i unplugged the vacuum tube and narrowing it down to FPR.

Even till now i still have doubt about the FPR, unless the new one is defective, which i have no way to prove it, unless i have another one but ain't going thru that trouble and waste more $ if ordering another one to prove.

Thirstyturtle

Alright well I've now changed all 6 spark plugs. During the process I checked all of the coilpacks and they all looked perfect and identical. I also cleaned the EGR ports (weren't terrible, but were a little clogged) and I ran a can of seafoam through the vacuum line.

Now I'll wait and see if I have anymore idle or starting issues and if the CEL pops up anymore.

What is the FPR? Fuel pressure regulator?
If my symptoms remain I'll look for a used one at the local Pick-N-Pull.

Here are some pics of the spark plugs, what do you guys think?








And finally, when I took off the top cover to clean the EGR ports, there was a decent amount of oil in there, is that supposed to be there?

Even at 220k miles this motor doesn't burn or leak ANY oil so I'm not sure how this oil got here or where it came from.

3.2TLc

Yeppur, the plugs definitely need replaced with new ones !!!

The oil laying within the intake normally occurs, don't really know why.

Nicks2001tl

A few obvious observations. Spark plugs for whatever reason have stood up to the test of time. Your EGR ports are very caked, which means that probably your egr valve is also gunked up. For under a hundred bucks you can get your car to run new again.


Also check your throttle body, clean if necessary lube the TB plate hinges. Clean and lube the throttle springs.


Getting back to your egr ports use a soft wire brush and not a screwdriver to get gunk out. Soak it with deep creep or brake cleaner.

Thirstyturtle

Thanks for the tips!

That picture is the "before" picture. Although I didn't take an after picture, I cleaned all the ports on the plate that I removed, as well as that gasket and the ports over to the right side of the photo using either a brush or brake cleaner or both.

The car seems to run excellently but if I have any further issues or CEL's I'll be checking the throttle body and EGR valve.

Where is the EGR valve?

Nicks2001tl

The egr valve is to the right of the oil fill cap. Two screws and a gasket.


The throttle body and plate hinges usually get done for preventative maintenance. The egr valve gets cleaned like the egr ports, but with something more sturdy like a thin screwdriver.

Thirstyturtle

Shibby! I'll check that out in a month or so during the oil change