Hey

I have a 88 gta with a 5.7 tpi
I'm having problems with the tps.
sometimes un plugging it and pluggin it back seems to fix it for a little bit. I tried a new one and no results.
I checked the codes and got a 22 and a 34 meaning low voltage to the tps and the maf sensor.

Anybody have any tips of how to resolve this.


THanks

 

get a voltmeter, or a multimeter. you need to see how many volts are gettin to the tps. disconnet the tps and use jumpers to jump the wires (i used paper clips). you'll need 3 paper clips. its just like you're extending the wire, and don't let any of the paper clips touch. your volt meter will have a black and red wire. stick the black voltmeter wire to the black tps wire, and the red voltmeter wire to the blue (i think) tps wire. you should get .54 volts at idle, then if you go to WOT you should have over 4 volts. it should also go up smoothly.

do this all with your car off, just make sure the ignition is turned to "on"

 

Actually, the '22' and '34' are indicating a low signal voltage FROM the TPS and MAF sensors. That is a bit different than what you implied.

The two could be related, or not. Since the MAF uses a 12VDC source for power, and the TPS uses a 5VDC supply from the ECM for power, there is not a likely electrical problem to the sensors.

It is more likely that the TPS base voltage is incorrectly set, and since the ECM relies heavily on the TPS signal to calculate an acceptable signal level from the MAF, the MAF code is also being set as a result.

 

Thanks for the tips. I was thinking that the two low voltages were related. Im going to try to adjust the tps that should help.
but now i have another problem. Im getting a code 42 now. THe car runs fine for about 10 minutes then misses like crazy and tries to quit at low rpm. Any ideas on this one. any help would be appreciated. THanks

 

The ECM can't tell anything at all about the world around it, except by what it sees via the various sensors. Consequently, it can be pretty stupid at times. However, its programming is smart enough for it to realize that certain readings from the various sensors can't possibly exist together; one such set of things is a high flow reading from the MAF (high flow = high engine RPM and large throttle opening) at the same time as a low TPS reading (throttle nearly closed). Either thing is fine by itself; but they don't go together. If that happens, the ECM knows something is wrong; it can't tell what, maybe, but something obviously isn't right.

The same thing applies in reverse: a high TPS reading (indicating throttle wide open), low engine RPM, and high vacuum (low load on the engine). Those 3 things can't possibly happen at the same time. Again, the ECM isn't going to come back and tell you "the such and such is bad, you need a new one"; but it knows something is amiss.

Most often in those circumstances, it's the TPS. Either check it, in which case I'd guess you have at least a 80-90% chance of finding that it's fornicated; or just replace it. Although, it's also possible that its wiring or connector could be damaged.