hey guys, new to the site. ive been looking thru your threads and i can tell this is where i need to be. i have been trying to figure out why cylinder four is dead. the spark plug thread was stripped out when i bought the car. i put a threaded sleeve in. new spark plug, new ignition coil, cause the other one was trashed from banging around on the front of the motor. [i hope it didnt short that portion of the ecu out with the coil hangining there. evidently the previous owner drove it like that for quiete awhile .]plenty of compression on that cyl. the code that is popping up is p1399 random misfire. i changed the fuel injector and it is basically doing the same thing. the check engine is flashing at an idle. but as soon as i start to accelerate the flashing light goes off. as soon as i slow down the light starts flashing again, any help would be greatly appreciated, thanks

 

Try pulling the plug from cylinder #4 and check it. Did ya use NGK's ?

Have ya reset the ECU yet ? It appears as though if ya have good compression readings and replaced all of the associated parts to cylinder #4.... then the random misfire may be somewhere else ???? Did ya replace all of the plugs ?

 

Thanks for the reply, 3.2TLc... We did use the NGK's Iraniums(sp) but only on cyls 4-5 and 6. I need to replace the 3 spark plugs across the back of the motor, closest to the firewall. We have been pulling the clock fuse to reset the ECU. It almost seems like when you accelerate #4 starts firing. It runs good when you're rolling down the road, and the Check engine light goes off at that time. But as soon as you let off the gas and come to a stop the light starts flashing again and you can easily feel / hear the cylinder drop out! Kinda baffling!

 

After ya reset the CEL, is it just the random P1399 code that appears and not any specific cylinder ? Replace the other plugs and check all the connections for the coils and fuel injectors.

Another thing may be that your EGR passageways or intake may be needing cleaned.

 

Yes, I'm going to stop and get three new plugs on my way home from work today. I should have done that already. When we first got the car there was other issues, but through trial and error, and referring to this forum for expertise, we got all the other codes resolved. I think there was a 0302, 0304 and 1399 initially with some trans codes, but there was no spark blug in #4 and the the coil pac was dangling with the stem broke off of it, so there was all kinds of codes reporting at first. Now the only one that comes back after a ECU reset is 1399. Yes we took the EGR off and cleaned what we could on that last night, and also cleaned all the passages on the plenum / intake.. Just don't know what else to look at if the 3 new spark plugs don't fix the miss, and clear the CEL! Thank you very much for your time! Gregg

 

The "trans" codes may explain the flashing CEL. Did the shift position indicator also flash ?

It appears as though you have not had the P0304 code come back for #4 cylinder, that's good ! How did the intake and EGR look ? Ya may want to have the fuel pressure checked. Look over the vac hoses.

 

We had a "Tranmission concerns" code and a "Trans temp sensor" code. (I forget the CEL numbers right now but I've got them wrote down at home) The D5 light was flashing. I replaced the sensor and did a 3x3 fluid change with DW-1 and all those codes dissappeared. D5 stopped flashing. Trans shifts fine, but the old fluid was nasty so still worried about that after reading the threads on here about these trans reputation for inherited anomilies. Plan to do another 3x3 as soon as I can get the car in somewhat driveable condition. The small ports (roughly 3/8" diameter holes) were half way clogged. We drenched it with carb cleaner and scrubbed them real good with small SS wire brush, and all the other carbon build up areas as well. I thought that would make a considerable difference, but it still throws that 1399 code after we got it back together. Fuel pressure hasn't been chacked yet, but that's a real good idea. I didn't even think about that. Would you happen to know what the pressure should be when you turn the key into the on position when the system is priming?

 

Been thinking and wanted to add: Where do you hook the fuel pressure gauge at? I just had the fuel rails off, and can't remember seeing any valve to hook the pressure gauge too!

 

Also try swapping the coil and the fuel injector with another one and see if the misfire is now on the other cylinder.

 

Yea, we've already traded the coils around, trying to identify if one coil was bad or not. If you stick a test light down into the electrical connector that plugs into #4 coil, it will not light the lightbulb at an idle, whereas it will light the lightbulb on all other cylinders. Its almost like there's no power coming from the ECU to that connector. (#4 cyl.) Like I mentioned earlier, when I bought the car, no spark in cyl 4, the stem was broke off the coil, the top part of the coil was still plugged into the elec. connector, just hanging there bouncing around on the side of the valve cover / exhaust man.. The kid I bought the car from was still driving it like that!!! I got the car for a song, but I hope that hanging broken coil didn't short out the ECU.

 

Hey 2GEEZ, look on top of the fuel rail.....you should see the pulsation damper which needs to be removed to attach the guage onto.

The pressure should be 41>48 psi with the FPR vac hose off & clamped. Then with motor running and v-hose put back on, the guage should be 32>40 psi.

 

thanks bro, ill get to that stopped at the store bought new plugs put em in cleared the codes. took it for a little ride still the same flashing CEL. Now we have new codes: 0302 Cyl 2 misfire, 0301 Cyl 1 misfire, 0304 cyl 4 misfire, 0300 Random Misfire, 1399 Random multiple misfire. Thats weird because the only thing we were gettin yesterday was code p1399. ill have the intake off to check fuel pressure in the next couple of days, checked all hoses everything is connected and tight. But these random misfire codes are kicking my ass! really appreciate your expertise.

 

Just verify the connector and wire are ok before venturing into an ecu. Trace the wire as far back as you can and test to see if you get any firing voltage on it. Maybe it goes to a harness, check that too. Good luck.

 

Thanks Vic! I keep wanting to forget that important fact, but you're right. There's something up with the elec on that #4 cly. I really didn't want to tear into the nice factory wire protection that runs to that coil, to start checking / tracing those three wires, but it looks like I'm gonna have too! I researched the site and found the pinout assignments for the ECU so maybe it might be faster to check the #4 cyl wires leaving the ECU while the car is running. See if I get a pulse there, and compare it to anothe cyl. If I get no pulse on 4, but I do on other cyl's, would that mean bad ECU for sure?
Thanks to EVERYONE who has been helping with this! I can never find the easy ones! My problems are always the ones that nobody's ever heard of before! Go figure!

 

Recheck all of your work including the fuel rail and injectors. Make sure all of the wiring and grounds are good. Search the site for more info on misfires.

 

Damn, if you get no pulse out of the ecu for #4, but all the other pins give pulses, then I don't know what other options you would have left other than an ecu replacement. Perhaps the dangling #4 wire you mentioned had touched ground and fried the output stage of that #4 circuit within the ecu and it can't send a pulse any more. Only a voltmeter test can verify this.

 

Yes, That's a good idea. Checking the grounds. One thing I noticed when we changed the spark plugs on cyl 1-2 and 3 last night. Cly's 2 and 3 plugs looked like they've been firing real good, but cyl 1, not so much. White on the tip, but alot of black soot around the shank of the plug where the threads start. It also looked like cyl 1 coil had been changed somewhere along the line. Just looked newer than the other two. Wondering out loud if Cyl 1 and 4 are tied to the same ground! Gonna check grounds and everything else weve done so far! Thanks again Guys!

 

Vic, I haven't tested the wire coming out of the ECU that controls #4 coil yet, but that's on the agenda. If I can someway get the ECU unbolted and pull it out enough to get a ice-pic style tested to that specific wire while the car is running I could verify whether it's hot or not, possible eliminating the need to trace the wire back from the ing. coil. I'm not sure if the harness leads that plug into the ECU are long enough to do this, but my intuition is telling me I need to try. I can usually track down dead shorts and misfires without any problems, but I've never ran into anything like this!!!

 

Hey 2GEEZ, The factory service manual which was available previously on this site for downloading, may be beneficial when getting into the more detailed electrical wiring and the ECU. There is also a specific troubleshooting section on testing the coils for voltage and continuity. May save some guesswork.

 

Service Manual

https://www.dropbox.com/sh/fnu2xclts...E%20MANUAL.pdf

 

You guys are awesome, but I've tried to down it twice now and keep getting a "corrupted dictionary error" when I try to open it. Not sure if it's my copy of Adobe Prof. or not! This would be a very helpful tool to have! Does anyone else have a link to a different copy of the same service manual?
Thanks in advance!

 

Before you start chasing down pcm problems, make sure you've got battery voltage at the black/yellow wire at the coil connector. Key has to be on, engine running or not, doesn't matter. I've run into a couple where the wire was broken inside the insulation less than 1/4" from the connector. All six coils are fed power from fuse #11 in the under dash fuse panel. The junction is in the wiring harness under the hood, near the driver's side firewall if I'm not mistaken. If you have no power at the coil connector, you can tap into another coil's power feed. It's not necessary to go all the way to the junction. If you happen to have a break right at the coil connector, the easiest fix is to pick up a used coil connector with a few inches of wire at a salvage yard. By the way, all the coils also have a black wire (ground). The pcm triggers the remaining wire. (each coil has a different color wire on this one)

 

Thanks TLer, Everything you say is sure ringing home. I can stick a simple circuit tester into the center wire on the connector and get nothing on cyl 4. (the problem cylinder) whereas I get voltage on all other coil connectors. I thought about stripping those three wires out of the factory provided wireloom and start tracing it back to the firewall, but thought, , , "What's the chances of the wire being broke without visible damage?" Well, if you've had this happen to you before, and in my case, the dang COP dangling on the side of the motor for lord only knows how many miles, I feel theres a very high probability that this could be my problem. I've been hesitant to pull the ECU as I've read here that these units seldom create a problem on TL's. PLUS the fact that the boss has decided I need to paint the WHOLE house interior in preparation for her new carpet installation. So Ive been juggling projects for the last few weeks, and it's still kinda cool weather here in N KY, but I will definately probe around on this wire as soon as I get home this evening. Thank you Very much for chiming in! Hopefully I'll have a positive update tomorrow!

 

Hey 2GEEZ, how did the painting go ? Sure hope that the boss is happy !