On my 91, as soon as I turn the key the temp needle shoots straight up to the H even when the engine is cold. All of a sudden it happened. I thought I was overheating but nothing appears to be wrong. I'm guessing something with the temp sending thing right?
My engine is stock if it helps. D15.

I want to get this fixed quickly in case I actually do end up overheating.

 

you most likely have a short in the coolant temp gauge sender wire. Find the coolant temp sender (directly below the distributor) and trace the wire back to the cluster.
The helm manual shows how to test the sender with an ohmmeter if you have one.

 

aah I dont have the helm manual. What exactly do I do to test if this lil bugger works?
I've got an ohmmeter.

 

I replaced the coolant temp sensor and the needle on the gauge still flys up! wtf?
Any help?!

 

Thats because it's not the cause of your problem.
Like i metioned before trace that wire back to the cluster. unloom the wiring and look for a break in the wire.

by the way the reason for testing the sender is to keep you from buying parts that you dont need/wont fix anything. so diagnose first, buy parts later if needed.

 

your temp wire is gounding out somewhere on your car. happened everytime on my car too

 

back in the days i has that problem and it was a short.....

 

I have this problem also on my project crx but I havent had time to fix it yet thanks for the info!

 

Actually after replacing the sensor it seemed to go back to normal a few times and then go back shooting to the H. So I'll definitely check that wire, that could it.But I got a bigger problem with the stupid thing before I go looking for the wire.

 

You could use a lot of time and energy undoing the loom and tracing the wire to find out where it's shorting, OR you could just run a new wire (a lot easier).

 

it might be a sensor

 

wrd