Will a faulty temp sensor cause the gauge to read incorrectly to where it messes with performance? My problem is that the car was rigged to run manual fan all the time. And I replaced the stock thermostat with a 180' unit. But the damn stat barely ever gets open, at least thats what the gauge says. If the gauge is reading correctly then my car never gets above 120' because it very rarely makes it to the first hash mark. Only with the AC on during a moderate temp day will it ever stay there or slightly above. On the freeway, it doesn't even register. WHAT GIVES??? Is it the gauge? I replaced the sensor on the front of the intake manifold right above the water pump. I believe this one is for the ECM correct? The one on the pass side head should be for the fan, and is there one on the other head for the gauge? Or does the gauge get its reading from the ecm??? PLEASE HELP ME FELLAS? this has been pissing me off for months.

Thanks

Will

 

I'm leaning towards it being the gauge because when I start the car cold, the needle is buried almost 1 hash mark below where it should start reading on the gauge. And if I were to run the car, shut it off, and come out a few minutes later to turn it on, the needle will do the same everytime its shut down, and then barely ever come back up.

 

Sensor on front of manifold with regular 2 pin plug is for ECM input.

Sensor next to it with injector type plug is temp sensor for CSI.

Sensor in driver's side head is for gauge

Sensor in passenger head isn't a sensor at all, it's a fan switch. All it does is switch on and off.

 

Can you elaborate on the sensor for CSI. Whats it control? Thanks

Will

 

something to do with how long the cold start injector pulses for startup.

Not sure if 89 has it, I think it's a crossover year. I know my 85 and 87 had it.

 

Yeah its weird, I don't have the 9th injector, wonder why its still present

Thanks

Will

 

Here is a picture of the Coolant Temp Sensor and an explanation of what it does. It is located in the front of the intake manifold below the throttle body. And there is a cold start injector on the 2.8L V6 engine.

 

he gots the L98 though

Do you have a whole collection of those pics hosted somewhere trickster? I sure would like to get my hands on them

 

Hello onebinky,

I know he has the L98 in his car, I just mentioned about the 2.8L having it because of the reference to the cold start injectors that's all. Not trying to confuse you or him. No, I don't have these pictures hosted anywhere. I have the GM service manual scanned into my computer in adobe acrobat PDF format and can reference to what I need, and use photoshop to convert it to a usable format for the board. Makes for a nifty show and tell doesn't it?

 

What brand of thermostat did you install?

 

lol, yeah. I'll have to look into getting something like that

 

Got the thermostat at napa

 

What temp range was it?

 

its a 180' ish

 

I don't know why this happened, and since this thread is talking about the temp gauge, I figured this would be the place to ask this. Yesterday when I was on my way to work, I noticed that the needle on my temp gauge would not move past the 100* mark, which is the first mark. I always keep an eye on my gauges when driving and noticed this happening yesterday and it is continuing to happen. Has my temp gauge up and died on me or could it be something else? I have my fans on an override switch and keep them on at all times unless it is fairly chilly outside. Any help with this would be greatly appreciated.

Sorry to hijack your thread with this question, but I figured that since this is the subject you were on I would ask.

Thanks for the help guys.

John