I have a 94 trans am with an LT1 in it. The opti has been replaced about 25k miles ago. The ICM tests good, coil, tests good, coil wire test good. I checked all the plugs to the harness, and ohm’d out the opti harness, and cleaned the connection plugs. The MAF I cleaned also, and didn’t seem to make any difference.

The car runs fine 95% of the time when it is below operating temp. But as soon as it reaches operating temp (around 180-185*), idling or driving the car will want to stall. As soon as I put it in neutral and rev it to about 3k rpms it throws the CEL and runs perfectly fine. It will idle smooth at 650rpms; it will run to 6k without a miss or hesitation.

The fuel pump was replaced at the time the opti was, and so was the filter (all from previous owner, and I have receipts for it. The plugs and wires (moroso) were replaced about 20k miles ago ( have owned the car just about 18k miles now).

When I monitor the info, only thing different I see is it pulling 9* of timing under WOT, which is normal I assume for a stock tune and bolt ons. Occasionally it will just crank and crank, but then after trying for about 3-4 times, it will fire up, miss a little from too much fuel, and be fine till it reaches operating temp. The code that it throws is DTC36, which is high resolution pulse failure or something to that sort. I will see if I can save a data log and upload to see if you guys could see anything funny.

Anyone have any ideas as to what it could be? I want to get it fixed so I can sell it, but I don’t want to put much money into it. Asking this question on an Fbody forum is a joke as I’ve tried before and no one was help at all.

Thanks

Aaron

no ideas?

thanks

aaron

I am unsure what you problem is, but it sound like it only runs bad in open loop (when it is cold). I would vist a 4th gen web site. I have recieved a lot of help from the ones below when I had my 95 formula.

www.mfba.org
www.camaroz28.com

Friend had that issue.
His was the Ign relay.
If memory serves (Yeah ,right) there's 2 relays side by side and 1 is for Ign, -try swapping them.
Don't recall what the 2nd relay was ,could be fuel.

thanks guys.
the issue is in both open and closed loop. yesterday it almost left me stranded with it just cranking, then i got it to fire. and ran fine rest of the day.
i did check it from open to closed loop, and it goes into closed loop a lot sooner than it reaching operating temp.
i tried cz28 but they all keep trying to say opti, which it could be, but i dont want to rule it out yet.
i have a 160* tstat i plan on putting back in, i think i will do it this weekend to see if keeping the motor cooler helps anything.

thanks.

aaron