Konstantine16

Started happened about a week ago. The worst time it gave me was when I drove to a store and the car acted completely normal. I got back in the car after leaving the store (car still hot) and it would not start but was cranking, after pushing the gas it would start but then it would sputter and stall quickly. After the 5th time starting it, it acted completely normal again. Then about a day after that the car starts to bog and lose all power in gear when driving on the road, and whenever it does this the temp gauge goes crazy going up and down on its own like its possessed. I get no check engine lights or anything while this is going on.

So far I've ruled out spark plug wires, fuel pump, and the car is not overheating.

poltergeist 02

iTrader: (65)

try replacing your coolant temp sensor

LS6427

iTrader: (2)

You have 1998...........do what "poltergeist 02" said. Almost all 1998's will hardly run when those sensors start to act up, and some later years do it too.

DO NOT tighten the sensor in too tight, it will snap off. Just snug, then half turn more with a ratchet. Run it to operating temp, make sure its not leaking at the sensor, and your done.

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Konstantine16

Had the coolant sensor replaced and it did not help at all.

LS6427

iTrader: (2)

Ok, you need to have someone check to see if the proper signal is making it through the coolant temp sensor wires to and from the PCM. Because your symptoms are a classic coolant temp sensor problem. It could be the wiring and hopefully not a PCM issue.

If that all checks out.....then start looking elsewhere.

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Konstantine16

Had the MAF replaced and the problems went away for two whole weeks. Then out of no where it started doing it again. I was taking my car to school and it drove perfectly normal the whole way there until I drove it back home and about 10 minutes into driving the temp gauge went up and down like crazy while the car was trying to die and stall out. To make matters worse I was carpooling a friend home and the car did this in the middle of a very busy intersection.

what the hell is going on...

lt1pwr1

iTrader: (1)

I agree with LS6427, I think you have an issue with the wiring. In particular, right at the connector to the coolant sensor if I had to guess. I see it quite alot with GM cars, the wiring break connection right at the plug that goes into the sensor. You can't see it necessarily, but it can be broken internally. Next time you get the car started and it seems to be running normally, try moving those wires up and down right at the connector to see if you can get the gauge to go crazy like you describe.

Also, if you have access to a decent scanner, you can read the coolant temp and see if it is pegged. I think max will be around -40 degrees and that would give you indication that you have wiring problems.

Konstantine16

thanks for the quick response. is it possible to order a new wiring that goes to that sensor without replacing the whole wiring harness?

LS6427

iTrader: (2)

Yes, you should be able to find just the plug end...then splice it in. I'm sure there's thousands all over junk yards you can go in there and just cut off the plug end. The same plug is probably used on many GM cars....

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Konstantine16

It does not seem to be the engine temp sensor causing the problem, I did a little experiment and unplugged it and the car started and ran fine. I think there is an electrical short some place in the engine bay. I noticed some weird corrosion looking stuff on the top of my battery which never was there before. Could a short or bad ground cause that as well as making engine stall, idle strangely and die out? I checked the PCM ground and it is secure so it is not that one.

Konstantine16

Car still suffering from this problem. Checked over all the wiring could not find any problems with it. Tried tugging on the harness while the car was idling to see if the problem would start but it would not.

The problem is very intermittent, it happens out of no where and I don't get any codes or lights on the dash just the temp gauge starts wandering around and the car idles rough and tries to die, if the car is in motion and I give it gas it starts bucking and the exhaust blows a very foul smell, I have to keep giving the car gas til it subsides and then it acts completely normal again.

My mechanic said the aftermarket fuel pump I had installed two years ago could possibly be overheating or going bad.

any thoughts or ideas? could VATS be causing this?

02camaroslpss

iTrader: (12)

Bring a post back from the past lol. Did you ever find the issue. My car is doing exactly the same thing. Going to check the connect but i have already checked all grounds.

Konstantine16

Hopefully you have better luck than I did. I ended up just selling the car because I could not get the problem to go away after replacing tons of parts and testing everything. Not sure what was going on but if you haven't already tried replacing the temp sensor, give that a go and see if its just that.

'Juwon

I have had the same experience a number of times. In fact, I have just had the experience today and I have it resolved already. The temperature guage read maximum, and the engine stalled without starting again, but just cranking as far as the guage was at the maximum level.

At a time, it was the EFI relay that was not electrically connected and I had to tap current from another wire to it. Today, it was the electrical connector to the ignition coil that I needed to replace.

zfastss

iTrader: (6)

I know this is an old thread, but I had this problem a few months back on my SS and found the issue to be as lt1pwr1 posted above. I had replaced the temp sensor with a new one and still had the problem. There were no physical breaks or burns in my wires, but I did find that the stress on the connector and heat cycling managed to widen the gap between the metal contacts in the the female end of the connector such that vibration or heat expansion would cause the male blades from the temp sensor to not make contact or make weak contact with the female side causing the gauge to sporadically dip to 0, jump back up, and make the car to run like garbage until the connection came back. The car is basically instantly adjusting the AFR thinking it is extremely "cold" which causes the hard start/stumble.
I diagnosed first by watching a scanner readout of the temp and jiggled the wire harness in the area after driving for a while and observed the same random temp movement as the gauge was reporting then found a few posts here saying that this connector is prone to having the female blades bend away from the sensor and make the connection loose.
To fix it, it took a small pick and pried the female ends of the connector closer together so they make solid contact with the temp sensor blades and problem solved. You could also cut the old connector off and splice in a new one with some basic solder skills. The pigtail is a part that you can easily find online or pull off from a junk car.

Hope this helps future folks that might run across this problem.