TPS is messed up...but factory manual says it is "not adjustable"....need help!!
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Joined: Nov 1999
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From: Charlotte, NC
Car: 1991 Camaro RS
Engine: GMPP 350 HO w/TBI
Transmission: 700R-4
Axle/Gears: 10-bolt w/3.73s
TPS is messed up...but factory manual says it is "not adjustable"....need help!!
my tps can be adjusted to the following values...
1.0 volts at idle, 4.0 volts at WOT, to...
1.25 volts at idle, 5.0 volts at WOT.
the car runs a lot better at the first set of values (1.0v@idle, 4.0v@wot). But, i knwo that this is wrong. it is supposed to be around .5 volts at idle and 5 volts at wot. what the hell could be the problem? this is the tps on a brand new hollet throttle body, and i have tried a brand new tps also.
the new one that i tried was from a '90 chevy full size truck with a 350. i wasnt sure what to get, so i asked the guys at NAPA to grab that one. am i using the wrong tps? i have the model 502-6 throttle body.
the driveability problems i am having are that the car stumbles and hesitates when i floor it. sometimes it is worse than others. it seems to be really bad when it is cold out. sometimes it hesitates so bad that it backfires and stalls.
the factory service manual says that the tps isnt adjustable. it says that the ecm takes the idle value and uses that as the zero position.
what the hell do i do? i know that i need a custom chip, but i knwo that the chip has nothing to do with this problem. its the tps that is causing it (i think). i realize that i will never get the maximum performance out of the car without the chip, but i also knwo that the car should at leats run correctly without it.
what can i do? get a tps from another car/truck? i am at the end of my rope trying to get the damn car tuned. please help. anything would be greatly apprecuated.
-brian
------------------
1991 Camaro RS
----------------------------------------------
Ultra Blue Metallic, T-Tops
GM 350 HO Crate Engine - Vortec Heads, Edelbrock Performer Vortec Intake, Holley 670 CFM Throttle Body, Open Air Cleaner w/14"x3" K&N, Edelbrock TES Headers, Edelbrock Victor Series Water Pump, Accell Superstock Wires, Cap, and Rotor, MSD Blaster Coil, Hypertech Fan Switch & Thermomaster Chip, AC Delco Rapidfires, 3" Cat Back, Flowmaster 40 Series Muffler
700R4 - 2,400 Stall Converter, Vette Servo, Shift Kit, B&M Super Cooler
Brian's 1991 RS
Central NY F-Body Association
1.0 volts at idle, 4.0 volts at WOT, to...
1.25 volts at idle, 5.0 volts at WOT.
the car runs a lot better at the first set of values (1.0v@idle, 4.0v@wot). But, i knwo that this is wrong. it is supposed to be around .5 volts at idle and 5 volts at wot. what the hell could be the problem? this is the tps on a brand new hollet throttle body, and i have tried a brand new tps also.
the new one that i tried was from a '90 chevy full size truck with a 350. i wasnt sure what to get, so i asked the guys at NAPA to grab that one. am i using the wrong tps? i have the model 502-6 throttle body.
the driveability problems i am having are that the car stumbles and hesitates when i floor it. sometimes it is worse than others. it seems to be really bad when it is cold out. sometimes it hesitates so bad that it backfires and stalls.
the factory service manual says that the tps isnt adjustable. it says that the ecm takes the idle value and uses that as the zero position.
what the hell do i do? i know that i need a custom chip, but i knwo that the chip has nothing to do with this problem. its the tps that is causing it (i think). i realize that i will never get the maximum performance out of the car without the chip, but i also knwo that the car should at leats run correctly without it.
what can i do? get a tps from another car/truck? i am at the end of my rope trying to get the damn car tuned. please help. anything would be greatly apprecuated.
-brian
------------------
1991 Camaro RS
----------------------------------------------
Ultra Blue Metallic, T-Tops
GM 350 HO Crate Engine - Vortec Heads, Edelbrock Performer Vortec Intake, Holley 670 CFM Throttle Body, Open Air Cleaner w/14"x3" K&N, Edelbrock TES Headers, Edelbrock Victor Series Water Pump, Accell Superstock Wires, Cap, and Rotor, MSD Blaster Coil, Hypertech Fan Switch & Thermomaster Chip, AC Delco Rapidfires, 3" Cat Back, Flowmaster 40 Series Muffler
700R4 - 2,400 Stall Converter, Vette Servo, Shift Kit, B&M Super Cooler
Brian's 1991 RS
Central NY F-Body Association
the first one is fine, as long as you have under 1.25 volts at idle, you wont get any fault codes and the ecm is right whatever is idle at startup is 0% which is why whatever voltage you set it at idle doent matter so much as long as its under 1.25, BUT it has to get past 4.0 volts wot
as long as it does that its fine and be sure there is a smooth sweep of a voltage increase as throttle increases
as long as it does that its fine and be sure there is a smooth sweep of a voltage increase as throttle increases
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