3.1 Wants to Stall During Warmup

[3X00-Modified]

You have two sensors, One on the back cylinder head that sends a signal to the dash guage, and then there is on on the cooling neck coming back from the upper radiator hose, thats the coolant temp sensor that sends the signal to the ECM to perform fuel mixtures and spark retard and such.

The one other thing is you said you never swapped out coils... Do you want a spare set to try and swap those out? I think I have a few spare that I could send you for trouble shooting... Even if its only one you can swap one out test, then swap the next and test, and so on... Let me know.

[john266]

You have two sensors, One on the back cylinder head that sends a signal to the dash guage, and then there is on on the cooling neck coming back from the upper radiator hose, thats the coolant temp sensor that sends the signal to the ECM to perform fuel mixtures and spark retard and such.

The one other thing is you said you never swapped out coils... Do you want a spare set to try and swap those out? I think I have a few spare that I could send you for trouble shooting... Even if its only one you can swap one out test, then swap the next and test, and so on... Let me know.

Now that I know which sensor is which, I will start by replacing the coolant temp sensor to see if that does anything.
When I swapped out the ignition module last time, it seems like 2 of the 3 coil packs have already been changed, because there is only one remaining pack that has the factory numbers on the top to designate which plug it goes to.
Do you honestly think a coil could cause the kind of problem that I'm having? I would think that if it was a coil, then the car would act up all the time, and not just occasionally.
I have been driving the car the last 3 days without issue so far, aside from the occasional loss of power during the times when the car is still warming up.

[3X00-Modified]

I've had a coil produce part throttle skips and lags, and then at WOT or idle it appears to run fine. This was a Accel coil though... not OEM ones... those do rarely fail.

If you can get your hands on a extra TPS I would also recommend that, but after doing the coolant temp sensor.

[john266]

I've had a coil produce part throttle skips and lags, and then at WOT or idle it appears to run fine. This was a Accel coil though... not OEM ones... those do rarely fail.

If you can get your hands on a extra TPS I would also recommend that, but after doing the coolant temp sensor.

Okay, I will install a new coolant temp sensor and TPS by this weekend, and let you know what I come up with.

[Cliff8928]

You have two sensors, One on the back cylinder head that sends a signal to the dash guage, and then there is on on the cooling neck coming back from the upper radiator hose, thats the coolant temp sensor that sends the signal to the ECM to perform fuel mixtures and spark retard and such.

FYI. If you have digital gauges, you only have the one sensor in the intake manifold.

[3X00-Modified]

If he had digital gauges and only one sensor, then (not to assume) but I would think he would notice that the temp reading would never climb... But then again who knows.

You do have analog gauges right?

[john266]

If he had digital gauges and only one sensor, then (not to assume) but I would think he would notice that the temp reading would never climb... But then again who knows.

You do have analog gauges right?

Yes, I do have the analog gauges.

-I installed a new coolant temp sensor in the car today (the one at the base of the water neck), and drove it approximately 80 miles today. I can't tell for sure at this point, but the car seems to be running a helluva lot better. Throttle response has improved, along with the hesitations and sputtering during warmup disappearing.

I am going to drive the car the next few days to see what happens, but I am seriously praying that this fixed the car.
I will keep you guys updated and let you know how things go.
Thanks so much for your help!

[Money pit Beretta]

That is very good news!

[3X00-Modified]

Awesome

The shitty thing about this, is I could have eliminated this issue at the beginning if I had access to scan the car, I would have noticed a bad or flukey coolant signal in the scanner.

[Money pit Beretta]

I had to google it, my scaner doesn't have a cord long enough to reach your car.

[john266]

Awesome

The shitty thing about this, is I could have eliminated this issue at the beginning if I had access to scan the car, I would have noticed a bad or flukey coolant signal in the scanner.

Actually I ran some diagnostics using my buddies' Snap-On scanner. We couldn't come up with much because the problem was so intermittant.

The sad part is how an ASE Master Tech had the car for over a month and still couldn't figure it out.....haha

[Money pit Beretta]

Good thing you updated this topic.

[3X00-Modified]

They never looked at the value of the engine coolant temp... Damn... That's like the first thing that I pay attention to, just be sure its registering since I know how much of your tune is dependent on that value.

[Luckymc420]

Well I learned something, I didnt think a temp sensor could mess up the car this much. Second, that they can jump around. I have only seen them work or not work. Interesting...

[3X00-Modified]

Might have been a connection issue too though.... cant rule that out.