Hello,
I have a 91 gmc jimmy 4x4 and once in a while for no aparent reason my service engine soon light comes on and stays on and the engine idles extemly high.I kinda figured the carb was just sticing open on me but i tried a ew things and now i'm not so sure thats the prob.Anyone have any thoughts or suggestions i'm a little dumb-founded by the whole idea and before i take it to a mechanic i thought i'd get a few opinions so any suggestions would be awsome!!!
Thanx Todd

 

hey todd sounds like the throttle position sensor or tps for short have had the same problem in a couple of vehicles i had

 

Please specify the year and motor you are working with.

Without knowing the year and assuming a newer blazer, I'd be more inclined to think it was the idle air control valve (IAC) sticking open. You really need to get the codes read to know more.

Here in the states, we can go to Advanced Auto, Autozone, etc to get the codes scanned. I do not know if the auto parts stores in Canada do this. I'll let one of our friends from the north comment on that.

 

I'm not sure of anywhere that will do it for free. I've only gone to my mechanic to git-r-dun once, so I'm not sure where you could go for a free check.

 

Auto Zone will read your code for free if you have that store where you live. They will give you a base line code. It may tell you what's wrong, but most likely you will need to dig a little deeper. That's when you'll have to go to a garage to get it read on a more sophisticated machine. It'll probably cost around $80 or so.

 

I went to auto zone for the same thing happening to have my codes read. Mine is a 1994 s10 blazer with an OBDI computer and they told me they only have the tool for OBDII. I bought a code reader and it came up as code 32 which is all EGR related. Your problem sounds a lot like mine. Look into your EGR valve possibly being screwed up.