I have a 1999 Staurn SL2. About 146,000miles on it. Automatic Tranny. It has a slight high idle at about 1,000rpm. No matter what gear i am in. When i hit the gas it wants to 'jerk' and then go but sometimes it stalls. When im just cruising down the road at any speed, I let off the gas a little and it jerks, and when i hit the gas to go faster, it jerks again. Also, recently it wants to stall when I am coming to a stop at a light or a stop sign, and I will go and it stalls. It doesn't do this all the time but I would like to know what you all think it could be and what I should check.


Please note: I have just done a full tune-up and it has a new fuel pump.

Thank you.

 

How much oil does it burn?
Ever cleaned EGR valve?
Ever changed ECTS?

Might be small vacuum leak but we'll go there if we have to

 

It doesn't seem to burn any oil. I haven't checked the EGR valve yet, i will try to get to that today. I haven't ever changed the ECTS, but my car doesn't overheat or anything, it runs nice and cool. A bad ECTS will start leaking coolant, and I don't. I know I have an exhaust leak, but i think all of my hoses are fine.

 

Alright, so i found out I can't take the EGR valve off until I can get a gasket for it, and i can't do that today. But i was doing some more research and found some info out on the IAC (idle air control) valve and the TPS (throttle position sensor). They were saying that it could be messing up my idleing and stalling. So i decided to take a look at them, clean them and test them. Now when the car is running, I unplugged the IACV and the car's rpms went up to 2800-2900rpms. Would that mean that the IACV is good or bad? Thanks

 

that would mean the IAC wasn't sending any signal to the PCM.....

IAC and TPS can indeed get dirty and contribute to driveability issues, but ECTS and EGR issues are much more common -- especially at 146K.

Good to hear you are not burning much oil.

Where is your exhaust leak?

A bad ECTS will not always leak coolant. It is a resistive device and can go bad. When it does it usually ends up telling the PCM that the coolant is at -40 all the time, so the car runs rich. Replace with brass tipped OEM ECTS -- the original resin tipped ones all failed. Replace connector too.

 

Well, i took the ECTS out and it is in good condition.

I drove my car yesterday to my dentist, and it doesn't seem to do the jerking as bad anymore, its just doing a lot of stalling now. Mostly when i am coming to a stop, the RPMs will go down to about 600 and then back up to 1000-1100. But it's when i hit the gas that it stalls. I almost got rear-ended at a light because of this. So i hope I can figure it out soon. Maybe a dirty fuel filter?? I haven't checked that yet because i need to get a floor jack and jack it up to get to the fuel filter, but that is next on my list.

 

IS the ECTS brass or resin tipped?
What is it resistance across the ECTS when the car is at operating temp?

have you pulled/cleaned the egr yet?

 

It is the old Resin tipped one, but there arn't any cracks or residue on anything, it looked good. I don't know what you are trying to ask about the "resistance across the ECTS when at operating temp.??

No I haven't pulled/cleaned the EGR yet, I will see if I have money to do it this weekend.

 

The ECTS is a device whose electrical resistance changes with temperature. The PCM interprets the change in coolant temperature from the change in resistance of the ects.

I am asking what is the electrical resistance across the two pins at the top of the ects when the car is fully warmed up. By knowing this we can determine if the ECTS is operating correctly and providing valid temp info to the PCM.

 

Well im guessing I need an ohm meter for that, and well I don't have one. I pulled the EGR and cleaned it, and it didn't make a change.