Codes: C or H
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Pro
Joined: Oct 2004
Posts: 619
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From: Reno Nv
Codes: C or H
I posted this in the Tech/Perf section and didn't get a reply. Anyone know why, after clearing everything and restarting the motor, I get H36 in 4.1 and not C36?
I've been hoping this would happen, Sound Nuts?
I've been chasing a problem. 92 LT1,6sp. The engine would cut out, stop for a milisecond, at low rpm. This would only happen one time and I could drive it some days without it happening at all. No codes, starts quick, idles fine.
Took it out 3/4 warm ( 165 ), ran it to 5k in 4 gears, no problem. Got it totally warm and let it heat soak 20 min. At 4k in any gear it totally shuts off or bucks really bad. Figured it's a fuel, closed loop or heat problem.
So I installed all the parts that have been sitting on the workbench for 2 months. Plugs, Taylor wires, MSD coil, and fuel filter.
Duck taped a fuel pressure gauge to the windshield, holds 42 psi when it shuts off at 4k. No codes.
Changed the ICM. No help, no codes.
Finally after driving around for 2 months, the service engine lite comes on and I get a code. What's strange is that it's H36 ( Opti hi res). If I clear it and cycle the ignition switch, I get C12 and - - - in 4.1. If I restart the engine, I get the serv. eng. lite and H36. I'm wondering why I'm not getting C36.
Any ideas?
Looks like I'm due for an Opti.
I've been hoping this would happen, Sound Nuts?
I've been chasing a problem. 92 LT1,6sp. The engine would cut out, stop for a milisecond, at low rpm. This would only happen one time and I could drive it some days without it happening at all. No codes, starts quick, idles fine.
Took it out 3/4 warm ( 165 ), ran it to 5k in 4 gears, no problem. Got it totally warm and let it heat soak 20 min. At 4k in any gear it totally shuts off or bucks really bad. Figured it's a fuel, closed loop or heat problem.
So I installed all the parts that have been sitting on the workbench for 2 months. Plugs, Taylor wires, MSD coil, and fuel filter.
Duck taped a fuel pressure gauge to the windshield, holds 42 psi when it shuts off at 4k. No codes.
Changed the ICM. No help, no codes.
Finally after driving around for 2 months, the service engine lite comes on and I get a code. What's strange is that it's H36 ( Opti hi res). If I clear it and cycle the ignition switch, I get C12 and - - - in 4.1. If I restart the engine, I get the serv. eng. lite and H36. I'm wondering why I'm not getting C36.
Any ideas?
Looks like I'm due for an Opti.
Burning Brakes
Joined: May 2007
Posts: 965
Likes: 13
From: turn 12 at Road America or TX
I posted this in the Tech/Perf section and didn't get a reply. Anyone know why, after clearing everything and restarting the motor, I get H36 in 4.1 and not C36?
I've been hoping this would happen, Sound Nuts?
I've been chasing a problem. 92 LT1,6sp. The engine would cut out, stop for a milisecond, at low rpm. This would only happen one time and I could drive it some days without it happening at all. No codes, starts quick, idles fine.
Took it out 3/4 warm ( 165 ), ran it to 5k in 4 gears, no problem. Got it totally warm and let it heat soak 20 min. At 4k in any gear it totally shuts off or bucks really bad. Figured it's a fuel, closed loop or heat problem.
So I installed all the parts that have been sitting on the workbench for 2 months. Plugs, Taylor wires, MSD coil, and fuel filter.
Duck taped a fuel pressure gauge to the windshield, holds 42 psi when it shuts off at 4k. No codes.
Changed the ICM. No help, no codes.
Finally after driving around for 2 months, the service engine lite comes on and I get a code. What's strange is that it's H36 ( Opti hi res). If I clear it and cycle the ignition switch, I get C12 and - - - in 4.1. If I restart the engine, I get the serv. eng. lite and H36. I'm wondering why I'm not getting C36.
Any ideas?
Looks like I'm due for an Opti.
I've been hoping this would happen, Sound Nuts?
I've been chasing a problem. 92 LT1,6sp. The engine would cut out, stop for a milisecond, at low rpm. This would only happen one time and I could drive it some days without it happening at all. No codes, starts quick, idles fine.
Took it out 3/4 warm ( 165 ), ran it to 5k in 4 gears, no problem. Got it totally warm and let it heat soak 20 min. At 4k in any gear it totally shuts off or bucks really bad. Figured it's a fuel, closed loop or heat problem.
So I installed all the parts that have been sitting on the workbench for 2 months. Plugs, Taylor wires, MSD coil, and fuel filter.
Duck taped a fuel pressure gauge to the windshield, holds 42 psi when it shuts off at 4k. No codes.
Changed the ICM. No help, no codes.
Finally after driving around for 2 months, the service engine lite comes on and I get a code. What's strange is that it's H36 ( Opti hi res). If I clear it and cycle the ignition switch, I get C12 and - - - in 4.1. If I restart the engine, I get the serv. eng. lite and H36. I'm wondering why I'm not getting C36.
Any ideas?
Looks like I'm due for an Opti.
intermittently run OK and then store 2 or 3 unrelated codes. A trip
to the junk yard for a used replacement fixed the problem. Turns
out the ECM is common to about 10 GM applications and the one
i paid $55 for was a remanned unit out of an 89 Olds. It might be
worth a shot to plug in a known good one ...
Thread Starter
Pro
Joined: Oct 2004
Posts: 619
Likes: 1
From: Reno Nv
Thanks for the reply. The 92 ECM is a different animal. It's only used on the 92-93 and one engine in the F bodies. They are harder to find and a little pricy. I don't have access to one to try it.
I wouldn't be supprised in the Opti is starting to go. 70k miles on a 92 is about right to start seeing problems.
I'm going to pull the cap & rotor today and see what they look like.
I wouldn't be supprised in the Opti is starting to go. 70k miles on a 92 is about right to start seeing problems.
I'm going to pull the cap & rotor today and see what they look like.
