'87 Excel idling problems - Hyundai Performance Forums

Vestrise · 04-11-2008, 11:39 PM

Okay, I'm new to this site, but I figured I'd ask here, since I'm at my wits end.

I own an '87 Hyundai Excel GL, running its stock 1.5l carburated engine. It's ran great and has been good on gas for about a year now, but all of a sudden my idle speed is up around 1800 rpm. I've checked almost everything I can think of, including:

-vacuum hoses
-oil
-radiator/engine coolant
-throttle adjustment
-those stupid impossible to reach speed adjustment screws

I'm pretty much down to just the throttle position sensor, but I haven't been able to find a replacement to even check if mine is bad since I also can't find the acceptable voltage ranges on it.

I also wonder if it's a part on the carburator, but I don't even know what the part is. It's a little fiddly bit that was originally covered by some sort of casing that I removed (looks like someone tampered with it before me). If I rock that piece forward, my idle speed goes to an acceptable level, and it's obviously thermo controlled, but I have no clue what that piece is or what it does exactly, since my Haynes' guide has no decent pictures and lists the parts as "rocker" or "switch" or some other undescriptive term and never goes into detail. If anyone else knows what that is, it's right over the throttle cable and behind the return spring.

Any other ideas, suggestions, or fixes would be a great help. Thank you.

Vestrise · 08-28-2008, 05:45 AM

Okay, I have gained a bit more knowledge and done a bit more to the car, and I still have that strange high-idle issue. I just replaced the carb with a rebuilt one, and in the process replaced the TPS. I am about to replace the O2 sensor, but I need to replace the exhaust manifold because, apparently, it's cracked. Despite the exhaust manifold damage, I don't think that's the problem, considering it seems to have been cracked for a while.

I also went through and reset the ECU (just disconnected then reconnected the battery after a while). Could my problem possibly be the ECU? Or is there something else I am missing?