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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: fabioblazer on June 30, 2010, 01:18:40 pm

Title: Rpm too high!!
Post by: fabioblazer on June 30, 2010, 01:18:40 pm

Hey guys! a question please

thanks!

i rebuilt my engine, all is ok, just a thing is weird.

i started engine for a first test, i removed valve cover, i adjusted valves and it ran good.

but when i reassembled valve covers, i started the engine again but, without touching accelerator pedal, engine speed (RPM) were so high that i had to shut it down!!

i saw that carb throttle linkage stop, doesn't touch fast idle screw as before!

someone has some good idea!?

Thanks for attention guys!

Fabio

Title: Re: Rpm too high!!
Post by: Grim 82 on June 30, 2010, 02:09:26 pm

Is the throttle return spring hooked up?

Title: Re: Rpm too high!!
Post by: jaredts on June 30, 2010, 02:35:40 pm

Is this a factory quadrajet (what carburetor)?  When it revved high did you try to tap the throttle to get it to idle down?

Title: Re: Rpm too high!!
Post by: fabioblazer on June 30, 2010, 02:55:14 pm

thanks for answer!
yes rochester quadra-jet. it has just 2 years.

i tried to close linkage manually but it's too hard, just if i turn manually the choke, throttle linkage touches the idle screw on the driver side, but as soon as i push down accelerator pedal, throttle linkage turns back but it is too distant from idle screw, as if i push down accelerator to the floor!

i tried to remove spring and accelerator cable, without nothing, but the problem remains

Title: Re: Rpm too high!!
Post by: VileZambonie on June 30, 2010, 03:41:19 pm

So you are on the fast idle cam then. Is the choke rod hooked up and moving freely? If so check the vacuum choke break.

Title: Re: Rpm too high!!
Post by: fabioblazer on June 30, 2010, 04:02:48 pm

all moves freely but throttle linkage doesn't come back completly.
maybe i must turn back choke linkage or precisly fast idle cam, but i didn't touch anything!
just after removing and reassembling valve covers
maybe i touched something but it would be extremly strange

Title: Re: Rpm too high!!
Post by: VileZambonie on June 30, 2010, 04:40:14 pm

Did you knock the vacuum hose off of the choke break?