saskdan97

I have a problem with misfiring and lack of power when I step on it. When just idling or just driving casually it runs okay. I am working on a fuel bleed down issue at the same time as the code 36 and 41 I received when checking codes. I had trouble as described about and running rough with stalls at lights. I changed the opti with a rich porter opti. I still had problems described above. Can someone help me in interpreting the results that I found from doing the opti and spark test that I found on shoebx site:

When I checked for signal from pcm to ICM white wire to ground while someone cranks it over I do not get 1-4vac as I should - I get no measurement. The two wires that go from the ICM to the coil get 12v with key on engine off. One of the other wires goes to ground and the remaining wire that is suppose to carry control signal and have 1-4vac gets nothing (zero measurement vac).

ICM harness:

A= yes got b/n 10 - 12 v
B = yes got 1-4 vac
*C = no got 2.0 ohms
D= yes got 10-12v

so did not get 0 ohms on C - what does this mean

optispark harness:

A= yes got 5vdc
B= yes got 5vdc
C= yes got 12vdc
*D= no got 200 ohms or .478 (2K) or 2.31 (20K) or 20.6 (200K) instead of 0-0.2 ohms ground
What does all this mean please? I did take it to a mechanic and he said the the pigtails seem a little funky and recommended changing them out which I will do. Thank you Dan

parkers Z28

Wish I could explain what the codes mean ...did you try to clean the pigtails ?
I can't explain what your codes mean but I can bring it back to the top for you ..
you need to post your codes on your other thread where shoebox and Fred have been helping you good luck

Injuneer

Might want to clarify the above.... did you get 1-4 VAC or did you not? IF you have no reading at all on the wire, pull the harness connector off the PCM and check the continuity of the white wire from the PCM to pin B on the ICM. If the wire is good, check the voltage at the PCM pin for the white wire. Use a digital meter with a very high impedance or you could damage the PCM.

If you don't get less than 1 ohm on the ground wires, you don't have a good ground. Try cleaning the connection to the block, or whatever the ground wire is attached to.

Again, unclear. You should get roughly the same resistance on each scale of the meter. Either you aren't getting good contact with the meter probe, or the meter has a problem.

DTC 36 tells you there is a problem with the high resolution pulse pattern from the Opti. The PCM is not seeing any pulses in between the 8 pulses from the low resolution signal. DTC 41 tells you theres an open on the circuit to the ICM. That could be the result of a bad white wire. I though I had explained this elsewhere????

Injuneer

I'm really confused. You have sent me PM's and Visitor posts asking me to respond to this post. Not only did I respond, but I went back through the PM's and found I had sent you a PM on 1/18 with detailed descriptions of DTC 36 and DTC 41.

I'm not sure what more you want.

You need to respond to my post if there is going to be any sort of progress.

saskdan97

the ICM was in backwards.