TPS SENSOR?

[trwp72]

I think the TPS sensor is again going out on my car... but in a weird way, that it has never done before. Yesterday when I started it at work, it was idling a little high, which I didn't think too much about... But, this morning, my car started acting up when I started it... Everytime I let off of the gas.. it would quit. I had a heck of a time just getting out of the driveway. And everytime it would act up, the "check engine" light would come on... and then quit. I thought it was just the cold weather, (It was in the high 20's this morning) So all the way to work, if I let up on the gas, the "check engine" light would come on, and it would start bucking... I noticed if I let up on the gas all the way, or at least partial throttle, it would not do it... just in the area just above idle... So... has anyone had a TPS act this way? I will go by and get a new one after work, if the concensus is that it is the TPS... I can't think of anything else it could be... I replaced one of these about 2 years ago... it was idling up about 2500 rpms when I first started it the last time.. (AFTER you put it in gear!) Almost ran into a wall at Waffle House! The main problems I have with this car is the crummy replacement parts any more...

I just did the following work last week on the car:

1. Tune up
Wires
Spark Plugs
Rotor
Distributor Cap
2. Gas filter

Less than two months ago:
1. New fuel pump
Fuel Filter
PCV screen and PCV valve
Intake cleaning

The car has run like new for the last week or so since the tune-up...

Any other ideas to check?

I can't run a check on the computer to see what codes may be set until Monday, as Advance doesn't have the OBD 1 any more...


Tom...

[cld783]

no point in guessing really.. check the codes

[trwp72]

I can't run a check on the computer to see what codes may be set until Monday, as Advance doesn't have the OBD 1 any more...

The problem is, I can't check the codes until MONDAY... when my mechanic opens, and I am off from work... (Since I work from 06:00 am to 6:00 pm anyway, and work both today and tommorow!) I do not want to wait that long... as it is driving me nuts trying to drive it this way!

[85crownHPP]

the IAC on the 91 has been giving me poor starts, but a few taps with a tack hammer fix it temporarily... TPS could be the culprit for the spotty throttle... the 91 also seemed to have a "buck zone" in the throttle until i replaced it with a CFI one, it also made the CEL come on. Also try pulling the vac hose off the EGR when its driving funny, a bad EVP sensor can make the EGR work when it shouldn't.

[murphmobile2]

Just take your TPS up to AutoZone and have them test it.

I brought mine in and tested it a few weeks ago.

[gadget73]

Sticky IAC sounds more likely to me. If you have a voltmeter, you can test the TPS pretty easily.

http://www.lincolnsonline.com/tech/00127.html

Analog meter works better for that, but a digital also works.

The IAC you can possibly fix by removing it and cleaning it out. They tend to get gummy, especially if they've gotten any oil residue in them over the years.

Also, if you're so inclined, a code scan can be done with a jumper wire and a test light:

http://fordfuelinjection.com/?p=13

[trwp72]

Where is the IAC at? Not sure which sensor it is...

[85crownHPP]

Its the cylinder shaped thing bolted onto the throttle body, facing the firewall - it comes off easy with a 8mm deep socket (might need a new gasket for it)
If i get motivated enough to mess with mine in the cold Ill take some pics.

[trwp72]

OK< Now i know what your talking about... Thanks Tom...

[86VickyLX]

Run a code check yourself, it's easy, you just need a jumper wire and you're good to go, since you have the yellow check engine light, you don't need a test light to perform tests.

[trwp72]

The car is fixed.... It had mostly stopped acting up tonight after work... So i stopped at Advance, and bought some Fuel injection / carb cleaner.. and sprayed it in the hole coming from the IAC, at the back of the throttle body (Best I can describe it!) Anyway, alot of brown stuff came out of the hole, I kept spraying until it came out clean. I guess it was oil, from when my PCV screen was plugged up... Anyway... It runs perfect now... just like new.

It doesn't get any oil in the area of the butterfly anymore, since the new screen and PCV valve was put in, it also stopped leaking oil around the top of the timing case cover, and no more blow by, AT ALL.... (Used to smoke like crazy out of the oil fill when you took the oil fill cap off... Even when the engine was off! Now, it doesn't even smoke with it running!!!)

[fordktpjoe]

The car is fixed.... It had mostly stopped acting up tonight after work... So i stopped at Advance, and bought some Fuel injection / carb cleaner.. and sprayed it in the hole coming from the IAC, at the back of the throttle body (Best I can describe it!) Anyway, alot of brown stuff came out of the hole, I kept spraying until it came out clean. I guess it was oil, from when my PCV screen was plugged up... Anyway... It runs perfect now... just like new.

It doesn't get any oil in the area of the butterfly anymore, since the new screen and PCV valve was put in, it also stopped leaking oil around the top of the timing case cover, and no more blow by, AT ALL.... (Used to smoke like crazy out of the oil fill when you took the oil fill cap off... Even when the engine was off! Now, it doesn't even smoke with it running!!!)

Could the smoking oil cap have been a side effect of the IAC? I have the smoky oil cap problem too, but my PCV valve and screen are less than 6 months old, so I know they're not bad.

And I too, have a "stumbly " idle, doesn't ever die, but it acts like it wants to, reckon I'll grab a can of carb cleaner and have a go at the IAC myself.

[trwp72]

No, the smoking quit after the PCV screeen PCV valve change... Sounds like you have blow by... How many miles are on the engine? And how has it been takin care of?? Not sure if the AIC causes that or not... Tom...

[fordktpjoe]

No, the smoking quit after the PCV screeen PCV valve change... Sounds like you have blow by... How many miles are on the engine? And how has it been takin care of?? Not sure if the AIC causes that or not... Tom...

Was handed down from my grandmother. Not sure about miles, odo broke at 76821, so I am sure it's over 100,000 by now.

Regular 3,000 mile oil changes though, like clockwork, I have all the records since it was new, only a couple are missing.

[gadget73]

All engines have some blowby. The PCV normally takes care of it, but what happens is the PCV system clogs up, and it forces the blowby out wherever it can go. This shows up as leaks, and goo inside the throttle body, since the oil fumes get pushed through that tube from oil fill to throttle body. The sticky gunky oil fumes collect inside the IAC and the rest of the intake, and then it doesn't run right. Usually fixing the PCV system stops the problem from getting worse, but if you don't clean out the goo from the IAC it doesn't get any better. A good snort with carb cleaner can't hurt anything at any rate.