Hey,

I have a 95 Z28 that has run perfectly for 180k miles. Recently, the car has started having an issue of sputtering and then throwing code 36 while driving 75 mph on the highway. Once, I shut the car off after this then it will not start again. Two times this happened and the car started after sitting for a week. The last time it did not start and is still not starting. I replaced the ICM and coil thinking that was the issue but no luck. I checked terminals A&D on the ICM harness and read 11 volts. I noticed there is an Ignition System Test Connector, is this the same as the ICM harness or is it a seperate connector? I saw in the FAQ that DTC 36 should not cause the car to not run but cause a different pulsing of the injectors. Any other tests I can do to determine what is wrong with the car?

Thanks for the help.

 

has the opti ever been changed? dtc 36 is falulty high resolution pulse or extra low resolution pulse detected. it is in the distributor ignition system. i would put money on it being a failing opti. should also change the water pump if doing the opti. dont get one of the cheap ones. a gm performance or msd is a good one. i had a gm performance in may last camaro and it was still goin at 100k. i have a msd in the camaro i have now and have had no issues for about 10k now. ill get some more stuff for ya in a minute.

 

this is what is in my 93 book.

 

Thank you for the information. The opti or the water pump have never been replaced. I am just dreading doing the opti change and was hoping it was something different. On the diagram you provided, is the Ignition System Test Connector different than the connector to the ICM? Also, is there anything in Chart A-3 "Engine Cranks But Will Not Run" mentioned that would help me since it does not run?

Thanks again for the help.

 

test connector is the place where the opti harness plugs into the main engine harness. a3 says to try unhookin the map so the computer will go to defalt and if it runs the map is failing. i think u have both map and mas but not sure and im not real sure how u would deal with those. maybe do one at a time. also points to checking the egr, fuel pressure and doing the noid light test on the injectors.

 

Well, I checked the test connector on terminal B on the PCM side and got 5 volts. I tried to test the terminal at the distributor and the connection completely fell apart. Looks like age and heat made the plastic connector brittle. At least it looks like I narrowed it down to the wire from the test connector or the opti. I will buy both since the connector is now not good. Does anyone know the part number for the 4 wire harness going from the connector on the passenger side manifold to the opti?

 

does it look like this
http://cgi.ebay.com/ebaymotors/ws/eB...#ht_1271wt_826

 

a little cheaper here
http://www.summitracing.com/parts/CEI-108097/

 

thank you for this..

 

That is the harness I was looking for to replace. Thank you craby for all the help.