I am trying to diagnos what I beieve is a bad TPS but the engine was transplanted into a Different car and I don't have a ALDL port to hook a scan tool to.
I measured the resistance accross terminals B&C and at closed throttle got 9.1KOhms. Smetimes when I opened the throttle the reading would drop like normal to anout 2.1Kohms but other times, right when I open the throttle levver I will see a spike to anything between 12Kohms to as much as 36KOhms. Then if you keep opening it, the reading goes back to reading normal. (Dropping in Ohms as the throttle is opened)
Am I checking the wrong Termianls?
The problem I'm having is when the throttle is opened the engine coughs and pops back out the turbo and wants to die. If you open the throttle up past say half throttle it will rev normaly but when it comes back to idle it wants to die and idles really low.
BTW, this is a 84 Engine with a 87 IC on it.
Any help would be GREATLY appreciated!! PLEASE HELP if you can!!!
Chris Anderson
Chris,
Why not "wire in" in the ALDL.
On the ECM A8 is data, A9 is Diagnostics(optional), ground is one of many (A12 for one).
The other option is to measure the VOLTAGE (key on, engine off) at the TPS (use the same connections as before) and use an osciliscope (prefered) or an analog meter. Slowly move the trottle to WOT. The action of the needle or trace should be SMOOTH.
Forgot to mention. should range from about .45 V SMOOTHLY to approx 4.8 V at WOT. See TPS adjustment in the tech section
Thanks. I will try and get the ALDL plug hooked up. So if I understand you correctly only three wires need to be connected to it?
Yep. What scan tool are you using?
it is a snap-on engine analyzer.