idle is still fluctuating, still throwing code for maf and TPS.

[Coreylt1]

okay so my car has been having trouble running on its own since day one of the rebuid, found that 4 spark plugs werent working, swapped them out and the car now is running on all 8 and idles by its self, but the idle is going from about 600 rpm to 1800 rpm, its very inconsistent, i clocked my tps at .67 and replaced my iac, just to rule it out. throttle body is glass beaded clean inside and out, new gaskets, doesnt get stuck or anything. ive replaced my tps , but i still cannot fix the problem. the code is p0122 (throttle/pedal position sensor A circuit low input). and the code is thrown with car off key on. instantly.

any ideas?

1996 lt1 t56 cammed, tuned properly.

[sweetbmxrider]

Use a scan tool with datastream and while observing tps voltage, jump the 5 volt reference and signal wire together. See if the scantool displays voltage above 4.7volts.

[greenformula92]

Yeah you must have a bad TPS reference wire somewhere. The TPS is giving one voltage but the ECM is seeing a different voltage

[Coreylt1]

Yeah you must have a bad TPS reference wire somewhere. The TPS is giving one voltage but the ECM is seeing a different voltage

where can i find a pin out of the wires to the ecm? and how can i find the problem with a multimeter

[greenformula92]

I honestly do not know what pin that wire is on the ECM. With a multimeter you can probe the wire back into the harness until you find something. You don't have to cover every inch on the wire....I would go ever 8 or 10 inches until you see some inconsistancy and then you can narrow it down from there

[Coreylt1]

I honestly do not know what pin that wire is on the ECM. With a multimeter you can probe the wire back into the harness until you find something. You don't have to cover every inch on the wire....I would go ever 8 or 10 inches until you see some inconsistancy and then you can narrow it down from there

can i have a quick run-down on how to probe it? im new to multimeters

[sweetbmxrider]

Dude I literally told you the next step in the diagnostic tree and you completely ignored it. I'm done with this.


http://www.myfacewhen.net/uploads/3131-nothing-to-do-here.jpg

[greenformula92]

bF3OyQ3HwfU

[Coreylt1]

Dude I literally told you the next step in the diagnostic tree and you completely ignored it. I'm done with this.


http://www.myfacewhen.net/uploads/3131-nothing-to-do-here.jpg

sorry lol im all over the place. i figured it out. the blue wire has a break somewhere. thanks for the help man. sorry for ignoring

[Pampered-Z]

What size cam, what size Throttle body? And how do you know the tune is right?

Have you also checked for vacuum leaks causing the surge?

[Coreylt1]

What size cam, what size Throttle body? And how do you know the tune is right?

Have you also checked for vacuum leaks causing the surge?

after tearing the wire loom and electrical tape off itturns out that the wiring harness i bought has been hacked to hell. but the problem with the TPS is due to a bad connection through one of the butt connectors. my new mission is to go through all these wires and resolder and test all engine sensors

[Pampered-Z]

after tearing the wire loom and electrical tape off itturns out that the wiring harness i bought has been hacked to hell. but the problem with the TPS is due to a bad connection through one of the butt connectors. my new mission is to go through all these wires and resolder and test all engine sensors

Glad you found the problem, hopefully is not too bad a job! There is a company (I'll have to go looking, but I think I posted a link some time ago) that sells all the GM wires and connectors at very good prices. I used them when I modified my wiring harnesses. Sourcing the various thin gauge wires and numerious colors can be a real pain!

[Coreylt1]

Glad you found the problem, hopefully is not too bad a job! There is a company (I'll have to go looking, but I think I posted a link some time ago) that sells all the GM wires and connectors at very good prices. I used them when I modified my wiring harnesses. Sourcing the various thin gauge wires and numerious colors can be a real pain!

oh wow that would be perfect! i started cutting off the 50,000 butt connectors that he had on, re-soldered and heat shrink'd them. its cleaning up nice. stocked up on alot of wire loom and some various colored rolls of wire. best $26 i ever spent

[Pampered-Z]

http://www.eficonnection.com/

[WildBillyT]

oh wow that would be perfect! i started cutting off the 50,000 butt connectors that he had on, re-soldered and heat shrink'd them. its cleaning up nice. stocked up on alot of wire loom and some various colored rolls of wire. best $26 i ever spent

Be aware that soldering wires can introduce resistance in the system.

[BonzoHansen]

but it's better than butt connectors lol

[Coreylt1]

beforehttp://i305.photobucket.com/albums/nn210/coreyronzel/harnessBEFORE.jpg
afterhttp://i305.photobucket.com/albums/nn210/coreyronzel/harnessAFTER.jpg