TPS/hunting problem continues......

[shendren]

well.....

-new TPS... still hunting/surging 200rpm

-filter in TPS line..... no fix... .

-took each battery off line (suggestion of bill k. )... no fix...

-tried the mystery switch... it's electrical

-my trans temp sensor is inside the trans... . (not easy for me to change)

-bill k. suggested a 20,000 uf @ 50vdc capacitor at the altenator per his electrical guru... .



any other suggestions?



thanks. scott.

 

[Bob Wagner]

Bill give great advice even when you purchase the other brand



Good Job Bill

 

[shendren]

what other brand?

 

[Missouri Mule]

shreden,



Just for the heck of it check(inspect and clean) connector for the engine speed sensor and while your at it check the senor (also know as engine crank sensor in gas and 24 valve engines).

Engine speed sensor is located on front of engine hoovering over the damper (takes a reading similar to timing light then sends the data to computer).

The connector is staight above sensor top/front of engine behind wiring harness.

The engine speed sensor connector because of being dirty or bent / loose pins has caused wierd things to happen (including engines to stall out while going down the highway).



The engine speed sensor has many functions, two of them is to turn on ASD relay thru the engine speed sensor relay. The ASD relay helps to control generator/alternator field.

Also its data is used to determine when to shift in and out of overdrive and torque convertor electrical engagement( thats three).



Good Luck

 

[Cooker]

Scott,



I wish I could offer some help, but is seems like you are covering all the bases I can think of. I hope you get things sorted out as I know what a PIA these kind of problems can be.



What about a new PCM I know it's expensive, but maybe you could find one in a salvage yard or possibly someone to swap with? Just a thought.



Ryan

 

[docdyno]

Mule's advice is a good direction. Something else to consider:

I get the impression that you feel that the TPS is the cause of your RPM fluctuation. It in fact might cause RPM fluctuation if the TPS "dithers" (shows movement when, in fact, there is no throttle movement). More often that not, this is caused by a ground problem. Keep in mind that the TPS probably works off of only 0-5 volts and very low amperage. Becuse of this, a slight ground issue can manifest itself as a large electrical "swing" We usually find a ground differentiation between sensor ground and ECM ground. This can be measured with a lab scope. Since most of us don't have one, the next best service procedure might be to carefully clean all chassis, sensor and ECM grounds. I hope this proves helpful.

 

[shendren]

i just went out and sprayed the contacts on the engine speed sensor. getting a small wire tie back on was rear fun. thanks for the input. i will drive it again in the am.



the dealer reflashed the pcm today (didn't help). they said they did not know what to do. what a pos dealer! they did have a tsb for the 1999's that had the same symptoms. in the tsb was reference to the problem being the tps/transmission temp sensor/ and the alternator ($350). i will install a 20,000mf capacitor at the alternator as bill k. suggests as soon as the $44 piece comes in at the local electronics shop.



thanks. scott.