I still cant fracking figure my car out!!!!

[DJHA90]

For those that have read my past posts, I am still fighting problems with my car. Ive gotten rid of the original problems, but now the car Idles at 2500 RPM. Runs great 2500 and up -- but idles at 2500.

Can back throttle stop all the way out with no change. Checked the blade in the throttle body and it is completely closed.
Replaced maf, throttle body, IAC, TPS, PCV.
Checked vaccum pressure, cylinder pressure, fuel pressure, throttle cable, cruise control cable, tweecer connected, tweecer not connected...

I bought a motorcycle so I have something to get to and from work. But rain SUCKS. Ideas are still welcome... What can cause a car to idle at 2500 rpm?????

 

[HISSIN50]

What was the vac reading? I dont recall stuff from your other thread (if I even replied) but if you disconnect the IAC connector, what happens?

Good luck.

 

[MysteryMachine]

did you adjust the screw on the tb not the stop screw the other one?

 

[DJHA90]

Ok, Disconnected the IAC and there was absolutely no difference. Any other ideas? Anyone?

Thanks

 

[95GTV8]

TPS?
you said you checked it but i had an improperly set/defective TPS and it made my idle hang around 1300-1400.

 

[DJHA90]

Checked TPS and even replaced it...

 

[final5-0]

You know its nothing in the tune with the Tweecer discoed.

Do you still have your stock tb, maf, and the like.

If so, you could use them to test.

Grady

 

[MLC Stang]

A big vacuum leak somewhere in the intake system, or a bad sensor somewhere.

Have you read your trouble codes out of your computer?

If not, that might provide some clues.

 

[DJHA90]

Tried it with stock Maf and stock throttle body. no difference. checked for vaccum leaks with spray. Nothing found...

 

[final5-0]

A big vacuum leak somewhere in the intake system, or a bad sensor somewhere.

Could be

He said he had the tb blade stop screw all the way backed out.

Seems like if he had a v leak that bad, it would never idle. Usually, if you got a bad v leak you gotta hold the throttle open to compensate.

Another thing about a bad v leak, you usually ask yourself ...

"Whats all that sucking noise?"

I duno Hard to help over the internet... ain't it

I just thought of something ..................

With the Tweecer connected, what kind of closed throttle tps voltage do you see?

Grady

 

[DJHA90]

"With the Tweecer connected, what kind of closed throttle tps voltage do you see?"

Ill check that as soon as I can get over to my son's garage. Has more space there...

 

[DJHA90]

Ok, Still havent had a chance to get over to my son's garage with my Computer but had him check the voltage of the TPS with a multimeter. The result does not seem possible. He is saying that the Voltage on the test lead is 13v. That cant be possible unless there is a short to the 5volt lead -- can it? He is going to test the 5 volt lead this afternoon and see if it is reading 13v (Either that or he is just screwing up the testing

 

[HISSIN50]

Ok, Still havent had a chance to get over to my son's garage with my Computer but had him check the voltage of the TPS with a multimeter. The result does not seem possible. He is saying that the Voltage on the test lead is 13v. That cant be possible unless there is a short to the 5volt lead -- can it? He is going to test the 5 volt lead this afternoon and see if it is reading 13v (Either that or he is just screwing up the testing

You are correct.

 

[DJHA90]

Went over to test the car and the battery was dead... Jumped it and started it up. Now car wont idle without giving it extra gas. It also had a miss. Checked the TPS Voltage at 800 rpm and it was at about 1 volt. Let the car die and started it again. Back to the 2500 rpm idle and it would not go back down. Disconnecting Maf did nothing. Disconnecting IAC did nothing. Any other ideas short of arson???

 

[HISSIN50]

How was the TPS wiring otherwise (with regard to the 12 volts VREf you were seeing before). See the weird/coincidnental thing is that when one has a car that will idle ok, then idle up and hang and not come down till the car is restarted, that's a good sign that the TPS is bad. I know you replaced it, but I still wondered about the voltage to it, given what you have posted..............

Good luck.

 

[DJHA90]

Ive tried 2 different TPSs with the same results. Logged the voltages on a tweecer and they looked ok. Im really stumped. Any other ideas?

 

[DJHA90]

Ok. I swapped out the 65mm FMS throttle body (including electronics) and put the stock one back on. The idle has stabalized (although I have a slight miss). So I would assume it was either the IAC or TPS on the 65MM TB causing the problem -- even though both were replaced.

Guess I will work on the miss and say screwit on the 65mm TB given the number of angry hours already spent

Any suggestions for tracking down this miss now????