MY engine prollums

[uglyota]

97 GMC, 350 vortec, 4L60e, 4x4
lately when I start it, it revs to like 1500 and stays there for a half a minute or so...also doesn't drop back down to idle at a stop as quickly as it should. Same deal when I put it into gear from park...it kinda revs up for ten or fifteen seconds...like I'm powerbraking.

I'm thinking I may just need to clean the TB. Any ideas?

[Jackasic]

have you replaced the intake manifold gaskets? they go bad at 100k.

[uglyota]

I believe I can speak for Jerry as well as myself when I say "that's not very funny"

[cntryboy1865]

clean the throttle body, my brothers truck did the same thing, and that was the problem

[Jackasic]

what? it is a known problem on vortec's. they develop a vacume at 100k.

[jerryg79]

I believe I can speak for Jerry as well as myself when I say "that's not very funny"

I'd say that its not an intake problem an intake problem would be that it runs for 15 minutes and then runs like **** till it dont run at all.....eventually it dont run at all permanently

[agjohn02]

my first guesses would be a sticking IACM (idle air control motor) or a bad VSS (vehicle speed sensor). my lt1 had the same problems at first and i cant remeber what exactly fixed it. im still not running a vss so i think it was the iacm.

[jerryg79]

Damn i'm dumb, I have the scanner for our motor, bring it over on Thurs night and we'll hook it up. Give me a call on thurs. 713-857-7150

[uglyota]

kewl, thanks...engine light's not on though...could it still be throwing a code?

with the truck turned off and cold, if I work the throttle linkages at the TB, it kinda hesitates for a sec before dropping all the way closed. I'm pretty sure that's it.

I may devote a day and $24 to replacing the intake gaskets here pretty soon...just in case...I would think that if it was so common, Chevy would eventually do a recall on them

iacm sounds valid too, John...how much $$$ are those?

[agjohn02]

$60 at oreilly's. mess with the linkage first though. sounds like your problem. if that doesnt do it replace the iacm but keep it clean so you can return it if it doesnt work. not that id ever do something like that...

[uglyota]

thanks boyz...
does anybody know if I can still get codes if the "check engine" light isn't on?

[BigRedFord04]

OBDII (`96 and newer) should store codes.

[uglyota]

thx

[uglyota]

even if I've run the battery dead 2x in 2 weeks?

[jerryg79]

I'm home now if you wanna check it out, i'll only be here prob. till tomm. or sat. It'd be easiest if you have a laptop, otherwise i have to drag my whole computer outside.

Let me know.