Throttle position issue
Thread Starter
Staging Lane
Joined: Jun 2017
Posts: 56
Likes: 5
Throttle position issue Hi:
I have this 4.8 out of a 2001 truck on my engine test stand that I build myself. The ECU was worked on by Brendan at LT1 swap, just basic stock reprogramming. I did my wiring harness modification based on LT1 website.
Anyway, the problem I have is the engine revs extremely high, I don't have a tach connected to it but if I want to guess it would be 3000 and higher, at start and it doesn't settle down unless I disconnect the throttle position sensor connector. If I disconnect the TPS, it idles nice but of course if I try to rev engine (cable driven throttle) it revs up but then it tries to die when it idles. I thought the sensor might be bad, I swapped the TPS sensor with my other Vortec engine that I put in my 79 Camaro, no difference. So, any idea where to go from here and how trouble shoot? Could it be the ECU programming? Did I miss anything with my wiring harness modification?
Thanks
I have this 4.8 out of a 2001 truck on my engine test stand that I build myself. The ECU was worked on by Brendan at LT1 swap, just basic stock reprogramming. I did my wiring harness modification based on LT1 website.
Anyway, the problem I have is the engine revs extremely high, I don't have a tach connected to it but if I want to guess it would be 3000 and higher, at start and it doesn't settle down unless I disconnect the throttle position sensor connector. If I disconnect the TPS, it idles nice but of course if I try to rev engine (cable driven throttle) it revs up but then it tries to die when it idles. I thought the sensor might be bad, I swapped the TPS sensor with my other Vortec engine that I put in my 79 Camaro, no difference. So, any idea where to go from here and how trouble shoot? Could it be the ECU programming? Did I miss anything with my wiring harness modification?
Thanks
Seems wierd. Without a scanner to log tps %, your kind of in the blind. A bad tps will cause some crazy issues.
Check tb set screw to see if tb is closing completely.
No vaccum leaks???
Check tb set screw to see if tb is closing completely.
No vaccum leaks???
