Could a bad opti cause this?
Thread Starter
Racer
Joined: Mar 2014
Posts: 409
Likes: 7
From: Taunton MA
Could a bad opti cause this?
Still Fighting the same issue. When my '94 is cold (open loop) she runs perfect! once warmed up (closed loop) mis-fires, no power, and stalls. My vette mechanic thinks it is a bad opti, not adjusting to the timing commands from the computer.
it is the original opti with 74K.
The computer has been checked, no error codes, new plugs and wires. But the plugs keep getting fouled (old and new ones). fuel pressure is ok.
can a bad opti cause this only when in closed loop? Also, i was thinking it could be a fuel line blockage issue.
Any help is always awesome, thanks!!!
C
it is the original opti with 74K.
The computer has been checked, no error codes, new plugs and wires. But the plugs keep getting fouled (old and new ones). fuel pressure is ok.
can a bad opti cause this only when in closed loop? Also, i was thinking it could be a fuel line blockage issue.
Any help is always awesome, thanks!!!
C
Race Director
Joined: Oct 2005
Posts: 11,772
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
Ignition Control Module has been known to act "flakey" once the engine warms up.
I would suspect that before the Opti
I would suspect that before the Opti
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
I had similar problems with my last two opti's at about the same mileage. Except my misfires and stumbling was on light or moderate acceleration when engine was hot. If I drove real easy and light, you could mask the symptom and could reduce the effect by a down shift. Seemed to happen under higher load in high gear.
Also if the tack is unstable at an idle, that is a sign also of the opti. Mine bounced around at a smooth idle.
I never had codes and check everything also with no problem found. My engine never did stall. I did change the ICM before I did the opti the first time. In my case, the opti fixed it both times.
Also if the tack is unstable at an idle, that is a sign also of the opti. Mine bounced around at a smooth idle.
I never had codes and check everything also with no problem found. My engine never did stall. I did change the ICM before I did the opti the first time. In my case, the opti fixed it both times.
Last edited by pcolt94; Nov 14, 2014 at 10:46 AM.
Thread Starter
Racer
Joined: Mar 2014
Posts: 409
Likes: 7
From: Taunton MA
I had similar problems with my last two opti's at about the same mileage. Except my misfires and stumbling was on light or moderate acceleration when engine was hot. If I drove real easy and light, you could mask the symptom and could reduce the effect by a down shift. Seemed to happen under higher load in high gear.
Also if the tack is unstable at an idle, that is a sign also of the opti. Mine bounced around at a smooth idle.
I never had codes and check everything also with no problem found. My engine never did stall. I did change the ICM before I did the opti the first time.
Also if the tack is unstable at an idle, that is a sign also of the opti. Mine bounced around at a smooth idle.
I never had codes and check everything also with no problem found. My engine never did stall. I did change the ICM before I did the opti the first time.
Race Director
Joined: Oct 2011
Posts: 16,092
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From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Get the engine to stall. Have the LT1 noid light. Take a fuel rail cover off, disconnect a fuel injector connector, plug the noid light in. Start the engine, keep an eye on the noid light. If it doesn't light up while cranking, the opti is bad.
