: 01 Deville issues, no codes, no check engine light



cbgibson
07-20-09, 03:04 AM
Ok Guys I'm new to this thread and I need help. I purchased an 01 Deville with 120K on it about a month ago. Recently and intermittently, I'm having trouble with it.

Occassionally, when I crank it up, it dies. I have to gently press the accelerator pedal when I crank it to keep it running. When it does do this and I am driving it, if I take my foot off the gas and the RPMs drop, it also cuts off. I have to keep my foot on the pedal to at least maintain 800 rpms to keep it from cutting off.

Also, once or twice, it's like the throttle is sticking...every time it does it, it sticks at 2250rpm. but that is also intermittent and only happens when the other issue is not happening. Also, when this is happening, and I put it in park after driving it, the vehicle is idling at about 1500rpm.

Like I said, the problems are intermittent, no check engine light is coming on, and no other problems are happening.

PLEASE HELP! I have a family of 5 (with one more on the way) and I don't want to end up stranded somewhere!

Ranger
07-20-09, 11:35 AM
Simple fix. Clean the TB.

00 Deville
07-20-09, 02:10 PM
There's a step by step on how to clean the TB over in the Tech tips section of the board.

cbgibson
07-25-09, 03:41 PM
Thanks guys...I took it apart and cleaned it, using the separate cleaners, and no more stalling! BUT, I'm now having a problem with it idling high while driving...its like it wants to stay at around 1300 RPMs when I try to stop, but once again, intermittent....any ideas?

Submariner409
07-25-09, 04:40 PM
Idle Speed Control (ISC) learn or restricted passages - TB cleaner and fuzzy pipe cleaners. Maybe Throttle Position Sensor (TPS) connector or fault.

Use the sticky up top of the main Deville page or in the Tech thread, study up on your car's installed system, and pull your own trouble codes.

Ranger
07-25-09, 11:05 PM
You might try pulling the IAC valve on the side of the TB and clean out the passages like Sub suggested, but if they where clogged I'd expect the opposite affect. Did you clean the TB bore REAL good as well as the throttle plate INCLUDING the perimeter? Remember, the plate perimeter seats in the bore closing off all air and then only the IAC valve controls the air flow. If the throttle plate does not seat, air gets past and the idle goes up.

cbgibson
07-26-09, 07:17 PM
I cleaned the passage for the IAC as well as the throttle body.....both looked like new when finished. I also cleaned the IAC with the electronic cleaner.

Ranger
07-26-09, 08:29 PM
Did that help?

cbgibson
07-26-09, 08:58 PM
Ok...today it was hard starting, but no high idle....this thing is driving me crazy! I pulled the intake boot back off and double checked the butterfly flap, all is spotless...i pulled the iac back out, cleaned it again, and also recleaned the passage for it as well.......all this was done yesterday....and im still having problems.....

Ranger
07-26-09, 09:17 PM
Have you checked for a ripped plenum? That's the rubber coupler between the TB and the intake. It usually rips on the bottom where it can't be see. Spray some Brakleen around it and listen for an RPM increase.