87_gta

Hi there,

Before I start, yes I have used the search feature extensively.

Been having issues with the engine light coming on for code 42 and 43.

When this first started it was only 43 that was coming up. last time engine light came on 42 and 43 came up. I got my hands on a factory flow chart (got it from ALLDATA). The issue is intermittent. I can't duplicate it per se but the times it did happen I was driving her a little hard. Again it won't do it every time. Had the car out tonight and had no problems.

For the code 43 I have verified proper operation of the knock sensor ( I have a snap on brick scan tool to verify this) when I tap the pass side header knock will indicate yes. I have also inspected the sensor connector and it was connected and good shape. I also road tested the car with scan tool hooked up to verify that the forced knock test does happen as I can see the knock retard under load by 1-2 degrees only when at WOT or 3/4 ish. Just because, I did go through the flow chart and I have gotten to the point the chart says either faulty connection or faulty ESC module. Also when the 43 did come on the car ran like a bag of ****. upon restart, goes away and all is well.

For the code 42, the light does not come back since code is cleared. under diag aids on the flow chart it does say to make sure the men-cal is fully seated which I inspected ( it was).
I did follow the chart and it lead me to the possibility that either there is an issue with ckt 424, faulty connections or faulty ignition mode. I checked ckt from ecm connector to 4 pin at distributor and wire checks ok with multi meter. I also checked it at the connector above heater box. checked out ok to ecm and to distributor. So I do not believe there is a short to ground. Only thing that didn't work for me in the flow chart was when it says to probe ECM harness 423 with ohmmeter and ground then use test light connected to 12v and watch resistance. when you hit 424 with the light 423 should go high resistance. mine did not, it stayed below 500 when it should have went above 5000. This leads me to want to try and replace the ICM.

Now to the part where I'm not sure. I decided to inspect the ICM. I removed the cap and found there to be some oil under the cap. The distributor is not the OEM one. Years ago when my mini ram was installed the shop called me and said there was corrosion on my factory ICM and instead of replacing the module the replaced the entire distributor with a jobber unit. ( I think it may be Autoline brand). I do still have the factory distributor.

My plan was to replace the ICM, I do feel there is an occasional misfire from time to time. My coil, wire, plugs, cap and rotor are 2 years old. AC delco coil. Prob less than 5000 KM on the parts.

With oil under the cap does this indicate the distributor is bad? (please note I have checked my PCV system and it looks to be working just fine, I do have a breather on pass side due to aftermarket valve covers.) Could the oil be the cause of the intermittant engine light?

With all this said. Do I just replace the distributor assembly which will have a new ICM already? or do I just clean it off and replace the ICM only? In Canada the ICM costs 150ish for AC Delco. or for 195 I can get the reman dizzy from rock auto (or a better one. give me suggestions). New GM is about $700CAD so no thanks on that.

Thoughts?

Airwolfe

iTrader: (1)

You don't happen to need a NOS Genuine GM distributor do you?

If you do then look at my signature below.