KA24E TPS Poor Ground

[benemorius]

'90 240sx KA24E 180k

The third wire on the TPS harness connector is supposed to be ground, no? With the car on but not running, one wire reads about 5v, the middle never goes below 1.2v, and the other (the ground, right?) is reading about a .24v difference to chassis ground. I ran a temporary separate ground to the connector and the middle wire dropped down to spec. (.45ish)

I suppose my assumption is that the TPS connector's ground is bad, and my question would be do I need to make the separate TPS ground permanent, or is there a main ground somewhere I should look at? I have already replaced the ground that goes from the battery to the chassis and intake. Is there another that I should replace, or is it not likely to help?

[s13sr20chris]

bravo! an excellent diagnosis! i know quite a few professional techs who cant do that! yes, just cut the wire and run a new wire from the tps ground to a good ground. .24v is way too much voltage drop across the ground. after fixing you will want to disconnect batt over night to erase memory.

[benemorius]

Cool. Thanks for the kind words. I don't recall what I was smoking when I was last messing with the TPS, but I must have just been seeing what I wanted to see. Or perhaps my TPS is just flaky. I was going to make a permanent ground for it but this time the signal only dropped a few tenths of a volt with the new ground. Further testing of the TPS showed it is indeed bad.

I guess I'll replace the TPS and it's ground, redo the MAF ground, set the timing to where it's supposed to be, clear the ECU, and see where that gets me.

Do me a favor if you could? Merge this thread with that one --> http://www.nicoclub.com/zerothread?id=80115

They're a part of the same episode and I had thought that one was dead when I thought to start this one.

Thanks again.

[s13sr20chris]

i tried. it says the other thread was archived.