Hey guys!

I am asking this question for a friend... He's got a '94 Suburban with a carburated 350.

His wife overheated the **** out of it, and it blew a headgasket. He had a local guy change them out, and now it runs well at highway speeds, but has a hard time idling- it idles at about 350 rpms. If it's cold, it stalls.

His mechanical already tried messing with the idle speed, and even tried replacing an 'idle air control valve', but it didn't change anything.

If any of you guys have any ideas, he'd really appreciate it!

Pat

 

vacuum advance leak

http://unitwan.co.nr/rover.htm

 

Is the electric choke connected? Sounds like a vacuum thing but, just something else to take a look at if not. Good Luck

 

Being a '94 it is the oil style fuel injection (throttle body fuel injection)unless he swapped it over to a 4bbl.

If it idles to low while cold then it is a choke issue, either its not working at all or its only working part way.

If it idles low while hot then it is a fuel delivery problem.
Like a clogged fuel filter, a weak fuel pump or a clogged/dirty port inside the carb.
But since you said it runs fine on the road its not likely to be either of those.

Doing head gaskets all he would have done is remove the carb, and that means unhooking all of the cables for the throttle and choke.
That is where I would look, the throttle cable and choke/choke pulloff.

 

It could also be that the idle step up cam isn't engaging. Also hooked to the choke linkage.

As stated it should be TBI. The kids C10 is TBI and has same low idle prob. Haven't jumped into it yet, too bloody cold.