Help with TPS
Thread Starter
Instructor
Joined: Sep 2002
Posts: 116
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From: Boise ID
Help with TPS
I need some help solving an acceleration problem, I think it may be linked to the TPS. The car does not set any codes but has a horrible pinging problem. I had an 85 Z28 with TIP and noticed on that car that when the TPS was moved without moving the throttle the injectors would speed up and the engine would die. My 88 Corvette does not do this, you can play with the sensor without moving the throttles and all that happens is the motor will rev up slightly. Can someone with an 88 or later experiment with this and let me know the results, should you hear the injectors speed up or should the motor just rev slightly? Thanks for any help you can give. :steering:
Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
Re: Help with TPS (ethan1321)
Normally the TPS and throttle cable are linked, so when the ECM sees an increase in TPS voltage it increased injector pulse width (and apparently with an '85 ECM, the pulse rate).
With the throttle disconnected this would result in an overly rich mixture which would eventually stall out the engine.
Check your knock sensor as the ECM should pull timing when it detects ping. Also check base timing and move the TPS through it's range and verify with a DMM a smooth resistance change. Then reset base idle with the IAC and set the TPS to 0.54Vdc at base idle.
With the throttle disconnected this would result in an overly rich mixture which would eventually stall out the engine.
Check your knock sensor as the ECM should pull timing when it detects ping. Also check base timing and move the TPS through it's range and verify with a DMM a smooth resistance change. Then reset base idle with the IAC and set the TPS to 0.54Vdc at base idle.
Thread Starter
Instructor
Joined: Sep 2002
Posts: 116
Likes: 0
From: Boise ID
Re: Help with TPS (65Z01)
Thanks for the advice. I have checked the TPS for smooth increase and decrease in resistance, as well set base timing and idle. I have been fighting this problem with pinging for some time now, it happens at all times; cold, warm and hot. I thought possibly it might be that the equivalent of the accelerator pump part of the computer is not be functioning properly. I appreciate any more thoughts you might have on this.
