If it won't go above 1.7 then TPS could be shot.I would start with a new TPS.
TPS , or worse, problem
Basically I'm trying to get an 89 L98 to idle better. All of a sudden it will not respond to the throttle at all, just makes a sucking sound and dies as the throttle is depressed , even at no load. Has the correct voltage across the TPS resister and the resistance changes smoothly, but the signal will not advance above about 1.7 volts, should go to 5. Makes me afraid the ECM might have been damaged. Anybody have experience with this situation or have suggestions as to next step?
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TPS problem
I guess that was a dumb question at least as written. Obviously the TPS would be the first suspect. I was just concerned that since the resistance seems good, maybe I had damaged the ECM. A horrible thought. Thanks for the reply.
I guess that was a dumb question at least as written. Obviously the TPS would be the first suspect. I was just concerned that since the resistance seems good, maybe I had damaged the ECM. A horrible thought. Thanks for the reply.
I don't think you have a ECM problem ; it is not as if you injected a over voltage into it.I guess that was a dumb question at least as written. Obviously the TPS would be the first suspect. I was just concerned that since the resistance seems good, maybe I had damaged the ECM. A horrible thought. Thanks for the reply.
I replaced the TPS and have the same problem, engine will not rev over 1700 RPM, even backfires if you hold the pedel down. Now I'm really worried.
Have you checked the fuel pressure ? that is how it should run if pressure is low or it's out of Gas..I replaced the TPS and have the same problem, engine will not rev over 1700 RPM, even backfires if you hold the pedel down. Now I'm really worried.
David
Fuel filter could be plugged up.
Fuel pressure appears fine, a little over 40 lbs and stays steady. Fuel filter is new. This problem started when I disconnected the TPS while the engine was running. Is there a way to check the ECM, and if it is damaged, what is my next step?Fuel filter could be plugged up.
Sucking sound
It sounds to me like you have a problem with your IAC motor. Because you said it makes a real big sucking sound when you open the throttle. Or maybe I'm wrong in my guess.
It sounds to me like you have a problem with your IAC motor. Because you said it makes a real big sucking sound when you open the throttle. Or maybe I'm wrong in my guess.
Possibly bad MAF not letting ECM know air flow has increased so it can increase fuel flow.engine will not rev over 1700 RPM, even backfires if you hold the pedel down.
Try with MAF disconnected
I had this same problem with My camaro Iroc-z, it is a TPI car, turned out I had a bad prom, changed it out and runs great now.:banana:
What are your TPS WOT volts now?I replaced the TPS and have the same problem,
Have you pulled the codes to see if the ECM is seeing any faults.?
http://www.corvettebuyers.com/ecm.html
Not recommended. Have you reset the correct way?This problem started when I disconnected the TPS while the engine was running.
http://www.corvetteactioncenter.com...ow+to+Adjust+your+Early+C4+TPS+and+Idle+Speed
I took the MAF off and it runs about the same, very bad. I think I had the TPS misadjusted, used the wrong two wires, it now reads about 4.5 volts at WOT, but still runs the same.Possibly bad MAF not letting ECM know air flow has increased so it can increase fuel flow.
Try with MAF disconnected
Someone mentioned the PROM problem which sounds possible, is there a way to check it before I buy it, and is there only one? Thanks for the help. By the way, someone else mentioned the IAC. Don't think so because that should only be a concern at idle.
I mentioned the prom problem, and so far I havent found a way to test them maybe a dealership could give you some help there, or maybe someone on here can lend a helpful thought on checking it.
WAS THIS EVER SOLVED HAVING SAME PROUBLEMBasically I'm trying to get an 89 L98 to idle better. All of a sudden it will not respond to the throttle at all, just makes a sucking sound and dies as the throttle is depressed , even at no load. Has the correct voltage across the TPS resister and the resistance changes smoothly, but the signal will not advance above about 1.7 volts, should go to 5. Makes me afraid the ECM might have been damaged. Anybody have experience with this situation or have suggestions as to next step?
1 - 16 of 16 Posts
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