Carrera head temp sensor: quick test?
 

I'm dealing an issue on my father's 86 Carrera. Here are the symptoms:
-Mileage has dropped significantly
-Idle is rough
-exhaust is VERY rich
-removing the oil cap has no effect on idle

He was going to take it to a shop (he's 600 miles from me) but I'm headed up there next weekend, so I thought I'd try the "likely suspects" first to save him some money.

I've got an oxygen sensor for it, but now I'm wondering if I should check out the head temp sensor too. Is there an easy way to test this? I read the head temp sensor technical article, and it mentioned that if you disconnect the temp sensor, the idle should drop and the car will run rich.

I'd really like to know if the HTS is bad BEFORE I drive up there next weekend. If I have dad disconnect it, and it has no effect on the idle, am I safe to assume the HTS is bad?

Thanks!

(PS: I did a search before posting, and there's tons of stuff about the o2 sensor and HTS, but I couldn't find anything about a testing the HTS by just disconnecting it)

HI notfarnow
some info for your fathers car, hope it helps

this info is for educational purposes only!

http://forums.pelicanparts.com/uploa...1212152411.jpg

this is the test for the HTS.


http://forums.pelicanparts.com/uploa...1212152473.jpg

and the info for inspecting/checking it.

regards mike

Thanks mike, I actually have my Bentley open to that page right now!

The reason I was asking about a "quick test" is because my father is a bit mechanically challenged. Disconnecting the plug for the HTS would be about as far as he's willing to go, solo.

The part that got me asking about simply unplugging it was where it says:

"Temp sensor with break - richer mixture"

So if it's faulty and an "open circuit" is causing a rich mixture, disconnecting it should have NO EFFECT. That's my thinking

HI notfarnow
yes it will run rich, if you could get your DAD to get the engine running and warm, then pull the plug off and put a loop of wire into the plug he has pulled off it should run better/weaker, if that is poss'

regards mike

AWESOME!

Thanks for your help!