To the TPS and Electrical Gurus ...HELP !

[rbalach]

Last week:
- Driving on highway at 70mph, car looses power for 1/2 sec and then drives normal. Happens 4-5 times.
- Take exit and slow down to take turn (10-20mph) car stalls. Was able to start right back up
- Symptoms continue for a few days, stalling occuring more often now.
- NO check engine light yet

- Found main negative connection of battery slightly loose, fixed.
- No change in behaviour, still stalling.
- I remove MAF and TPS, sprayed down with ECC from Radio shack, reinstalled
- Car runs much worse now, major hesitation, CEL on, POWER light on
- Code reads 31 (bad voltage from TPS) for both CEL and POWER

With TPS removed:
White wire to ground : 4.72v (does not make sense to me)
Red wire to ground : 5.2v
Black wire to ground : 0v (almost)

The voltage between white wire and body being 4.72v does not make
sense to me ! Red and White wires are not shorted. The voltage stays the same with the TPS plugged in. Needless to say i am unable to adjust White to Ground to 0.5v.

TPS resistance:
Red to Black : 4.9Kohm
Red to White : 5.1Kohm (varies between 5.1 and 5.5 Kohm, dunno why)
Black to White: 250ohm (varies between 250 and 600 ohm, dunno why)

Bad TPS or something else ?

The resistance varies smoothly as i turn the back of the TPS.

I have dug through many TPS related posts and the only consistant things i see
is the 0.5v @ idle between white wire and body and that Red to Black should be
around 5Kohm

Any ideas ? All help is appreciated.

[JIMSVX]

I have a copy of the Service Bulletin that has updates to the Factory Service Manual for testing the TPS. It's located in my locker. How do your measurements compare?

[Landshark]

when you cleaned the MAF and TPS, did you allow them to dry thoroughly before driving the car?

did you clean the battery terminals and connectors before you tightened them? it may help - also make sure after they are clean you coat them with dielectric grease to prevent corrosion and place those little felt discs around the terminals, underneath the connectors (they are teated with anti-corrosion stuff).

seeing that you have 153,000 miles on your SVX, i don't think it would be insane to just replace the MAF and TPS with brand new ones - two less things to worry about.


preventative maintenance - its what's for dinner.

[rbalach]

Originally Posted by JIMSVX

I have a copy of the Service Bulletin that has updates to the Factory Service Manual for testing the TPS. It's located in my locker. How do your measurements compare?

Apparently when i reinstalled the TPS, i was off. I adjusted the resistance values to what is shown in the document in your locker, and it has started running fine (so far). And it hasn't stalled .... yet. Keeping my fingers crossed Thanks for you help Jim !