Help! Troubleshooting Code 36 and Running Rough

[LT4man]

Spark plugs and/or ignition wire condition will impact an engine under load. In drive, accelerating or in reverse. I would inspect the spark plugs and ignition wires VERY carefully. If you can get your hands on an Engine Analyzer, you would be able to see if there are any ignition firing issues.


Cracked porcelain (even a minute crack) on any spark plug could cause you problems.

 

[vigman]

Which is why I suggested this....

"run it at night... hood open.. and look for the light show"

 

[Schrade]

He's pulled a Houdini! Mighta' had somethin' to do with snippin' wires???

Backprobe sockets to test for current / continuity (this was a fan relay circuit diagnostic, checking for PCM-generated current at 218', if I remember correctly) :

 

[tonybabb]

This is so embarrassing....

Do you have a K & N or after market air cleaner ? ( Hint here, ones that use spray oil ).
Have you used MAF cleaner on the MAF internals?

Are the MAF and relays GM or other ( auto zone etc etc ) ?
recheck you wiring.. a wire might have popped off a plug or got burnt to close to the exhaust...

run it at night... hood open.. and look for the light show

Is 36 the only " current " code you have?

Open loop= car is not listening to the O2 sensors and running off an internal map ( till it warms up ).

Closed loop= Car is up to temp.. and is closing the loop ( intake to exhaust ) listening to the O2's and making engine corrections based on the O2's output.

Mike

It turned out the problem was the #8 plug wire (pass side, rear) was arcing like crazy. Replaced it and all is well. Now back to tracking down my Code 36 problem.
Thanks to all who made suggestions.
Tony

 

[John Robinson]

I don't remember were the number 8 wire is on an 89. Is it in the vacinity of the maf sensor or its wire? You might try clearing the codes and seeing if the code 36 resets. It may have been set because the bad number 8 wire was bleeding into it.

 

[tonybabb]

that's also a good suggestion

I don't remember were the number 8 wire is on an 89. Is it in the vacinity of the maf sensor or its wire? You might try clearing the codes and seeing if the code 36 resets. It may have been set because the bad number 8 wire was bleeding into it.

I'll reset tomorrow and see how it goes, if there's still a problem the Check Engine light will come on after about 6 start/heat/cool cycles.

This forum is awesome !!

 

[LT4man]

I don't remember were the number 8 wire is on an 89. Is it in the vacinity of the maf sensor or its wire? You might try clearing the codes and seeing if the code 36 resets. It may have been set because the bad number 8 wire was bleeding into it.

John,

#8 is the rear plug on the right (passenger) side.

On our LTX engines, that one is the most difficult one to replace.

 

[John Robinson]

John,

#8 is the rear plug on the right (passenger) side.

On our LTX engines, that one is the most difficult one to replace.

OK I didn't know that was number 8 I thought it was $^$^^%^$%%^&^&^&^plug

 

[John Robinson]

That wire runs underneath the wiring for the TPS, Maf, Water Temp wiring to the opti on the LT1. I wonder how close it runs to the those wires on the L98

 

[vigman]

That ALSO assumes

The wiring is using the factory routing , clips, etc.... which I'll bet money it isn't....

But Tony that's great news... however it probably needs a good hard run or two to clear the #8 plug....
AND the precat / O2 sensor on that side..

Mike