idle problems - I may have spoken too soon

[RealtyCaffeine]

Ok, the car died yesterday and while it would restart fine, it would not idle. Here is what I have done far:
New fuel pump
New fuel pressure regulator
New MAF sensor (about 2 months ago due to error code)
New IAC (adjusted on Friday and it fixed my chronic idle problem)
Verified fuel pressure at 50 psi or so static and 43 running
New fuel filter

The car starts and runs fine now but it has died once and would not idle. I drove it less than 1 mile two footed (brake and throttle) to a parking place and it was found to be idling fine at that point.

I have read up on Cam Position Sensor and I don't t think that is the problem. The tach seems to work fine which would not be the case if the sensor was bad from what I have read.

Are there any thoughts that you guys have that might help.

BTW, this is a stock 2001 GTP with 184K miles on it. I have owned it for more than 3 years and it had less than 100K on it when I bought it. It runs almost perfectly up to the last month or so. One more thing, I have noticed a very intermittent hiccup while running at city speeds. Sometimes it just seems to miss for a split second and then runs normally. Acceleration and all seem to be fine except for this.

Any advice??

Jerry

 

[minichopper6hp]

not entirely true on the cps, it has a high res and low res signal, while the low res signal could be working, the high res could be bad.
Any codes?

 

[jvee44]

I just resolved the same problem you experience on your 01 with my 00. This is what help my problem. I replaced the inline fuel pump resistor and that did nothing for the car. I then replaced the idle valve. However, on the idle valve you must have the correct length on the piston. If the correct length is not accomplish it will start, idle and shut right down. Try that to see what happens

 

[RealtyCaffeine]

Yep, I had the same issue at first. I adjusted the length to spec and it worked fine for a couple of days.

I have a new symptom I think and perhaps an idea to try. I was driving on a highway today and the engine "stumbled" or missed at highway speeds. I said "I wish this thing would just fail so i could find the problem" and i got my wish sort of. The engine started missing really bad and black smoke coming out the back I pushed on the throttle to try and get to a safe place to pull over and before I could get it off the road the problem disappeared and ran fine the rest of the day.

A mech told me it might be a defective engine temp sensor (not the gauge sending unit but a separate one) that tells the computer it is really cold (like -40 degrees) and begins dump fuel in via the injectors. Mech said that sometime it is just bad wiring to the sensor explaining the intermittent aspect of the problem.

Anyone confirm that this is possible?? Is there a separate sending unit on the 2001 GTP??

Thanks
Jerry

I just resolved the same problem you experience on your 01 with my 00. This is what help my problem. I replaced the inline fuel pump resistor and that did nothing for the car. I then replaced the idle valve. However, on the idle valve you must have the correct length on the piston. If the correct length is not accomplish it will start, idle and shut right down. Try that to see what happens

 

[RealtyCaffeine]

There are no codes or SES light. I did have one code we reset a bit ago that said it was running rich on bank 1. I had it reset and it has not come back. This might be related to the temp sensor problem, maybe see the thread below.

Thanks,
Jerry

not entirely true on the cps, it has a high res and low res signal, while the low res signal could be working, the high res could be bad.
Any codes?

 

[RealtyCaffeine]

new info on this one. It would not start and idle this afternoon after driving for about 30 minutes and sitting for about 60 minutes. I popped the connector off the MAF sensor and it started right up. Maybe NEW sensor does not equal GOOD sensor. I swapped it with a replacement and we'll see if that takes care of it.