dubai_c4

It's a glad to be owner of a c4 and i just bought one,the car was running perfect,but today when starting the car it will start and shut at the same time i noticed the cooler fans will start when car switch is in on postion.

Mr Angry

LT1? Cold start? If so, that's almost a dead giveaway the temp sensor is bad. Never had it happen on the Vettes, but it did on TONS of LT1 F-Bodies I owned. I fought it like mad the first time it happened, even going so far as to replace the Opti that time.

I didn't find it until I started using Tunerpro, and noticed the temp sensor was always jumping from -400 to anything and everything under the sun, and was flipping the computer out.

It's the one in the water pump, not the head.

antfarmer2

drain some coolant first so you do not get your opti wet.

dubai_c4

1.I have a superchips tuner which i used to tune it on my 07 tahoe,will it work and pull some codes from the 96 vette?

2.I've seen 2 water coolant tanks,which one i should drain and how much drain? also can i see any pic to the bad sensor that should be change?

antfarmer2

I would use the drain on the bottom right inside of the radiator. The sensor is on top of the water pump. Make sure you burp all the air out after.

Sid.123

Just a thought but you haven't left a paper clip in the diagnostic socket after checking codes
i noticed on mine that the cooling fan runs with the ignition on while your getting the codes.

Mr Angry

1) No, the Superchips tuner handheld is pretty crude by tuning standards, and doesn't work with the C4. Most C4 cars are OBD1. '96 was the changeover year.

I used Tunerpro RT, and found it while datalogging. I built my own ECM interface. To be honest though, the part is about $30, and is likely the issue.

2) Drain from the petcock on the radiator. May as well just dump the coolant and put fresh in. You can also do it by pulling the lower radiator hose off the radiator.

But a plastic bag under the water pump to cover the Optispark distributor. There WILL still be coolant in the system when you take the sensor out. It just unscrews from the front of the water pump.

When the first one went bad on me, the car would not only be hard to start, but as the sensor shorted, it would spit, pop, and generally act crazy. I've had other ones that just died and caused the hard start issue, but would otherwise run ok.

dubai_c4

I am so surprised how fast answers and help i got you guys are too kind with me i will start doing all of the above advices and let you know what i got but i have one last question,what is the sensor part number?

dubai_c4

Just 2 update u guys,i took the car to dealer they checked the car by tech 2 and found fuel pump fault gotta replaced with filter all system reset and car is perfect.total cost was $300 parts and labour charges.I am soooo 😊

kg4fku

Awesome!

Glad you got it sorted.