Engine popping and Knock retard only after 30 min. of driving not when cold

[Mikey T]

Hey guys I was hoping for some help.I have an 87 turbo regal that runs and holds boost perfectly,but only for the first 20 minuets of operation on cold starts,after that popping,KR,and service engine light fluttering when I go WOT.I have 42 lb.injectors,adjustable fuel pressure reg.hot wire kit and fuel pump upgrade,ls1 maf sensor & translator, turbo tweak chip,stock turbo,160 degree thermostat, scan master and a power logger.I do not have any trouble codes,and all numbers seem to be in range.After the car is driven for about 30 min.I am not able to go WOT without problems.Fuel pressure checks out pound for pound under boost.Any ideas on what is heating up causing this malfunction?If I leave the car sit overnight it runs like the monster these cars are, burn outs in second gear,but after 30 minuets of driving troubles occur.Thanks in advance.

 

[TexasT]

Did you check the resistance across the coils when you get her warmed up?

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[earlbrown]

My first step would be to swap in a known good ignition module/coil pack.

Short of that, split your two while the engine is messing up. If the potting material is soft and gooey, that's your problem. (and that stink... OMFG!)

 

[Mikey T]

Did you check the resistance across the coils when you get her warmed up?

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Today I checked the resistance across the coils,9.5,for 1 and 9.8 for the other 2,I replaced the coil with a used one, 12.5 across the board resistance ,car ran great for 30 min.then 2.3 KR and popping with service engine light flicker I also notice two cracks along the ignition module while changing coil.After engine runs for 30 min O2 sensor numbers drop during idle into the 062-200 range then misfires a bit then returns to the 800's.Thanks for a step in the right direction

 

[Mikey T]

My first step would be to swap in a known good ignition module/coil pack.

Short of that, split your two while the engine is messing up. If the potting material is soft and gooey, that's your problem. (and that stink... OMFG!)

I split the two apart no melting or gooey stuff.O2 numbers drop during idle sometimes almost to 000 then misfires then back into 800"s

 

[TexasT]

Sounds like its time for a different module too.

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[earlbrown]

With the o2 dropping to 000 that might be a corroded connection on the injector harness. That kind of failure usually isn't heat related though.


Is there a code during the SES light flicker? Can you post a powerlogger file of the misfiring?

 

[Mikey T]

Sounds like its time for a different module too.

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Yes do you know which module is best to use?

 

[Mikey T]

With the o2 dropping to 000 that might be a corroded connection on the injector harness. That kind of failure usually isn't heat related though.


Is there a code during the SES light flicker? Can you post a powerlogger file of the misfiring?

The o2 never goes all the way to 0oo but it has gone to 062 and 100's then back up to 800.There is never a code during popping and Kr retard at WOT just madness.I am going to post a power logger file tomorrow cold start burnouts and operating temperature misfires.

 

[usetaboost]

Check for loose battery wires, ground wires, etc. If it isn't that you probably have a bad module/coil. Wouldn't hurt to have a look to see if the crank sensor is broke. Plastic rots, I just saw it yesterday.

 

[TexasT]

I'm pretty sure I got mine last one from the local part house. Been a while I don't remember. Nos4gn, gbody parts or the like. Caspers has a high out put coil but I didn't see a module there.

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