help with '84 carb

Reply Subscribe

Thread Tools

Search this Thread

Nov 18, 2006 | 06:47 AM

kjdunn

Thread Starter

New User

Joined: Sep 2004

Posts: 9

Likes: 0

From: north-east tx

help with '84 carb

I have an '84 f-150, 302, auto-overdrive, w/motorcraft 2bbl. When I got the truck it idled very fast, previous owner said needed carb rebuild. took carb off & had rebuild done, guy said it was pretty bad. Runs better but still idles high, have backed idle adjustment all the way out, only way I can find to lower idle is retard timeing or carb mixture. the latter roughens idle. Is this carb supposed to have 2 of the black spacers to the intake, could these be my problem? Probably get'n 10 mpg at most. Starts and runs good except that it seems to start after I release ign., For this I replaced the switch down low on the steering column, but, still does the same thing. It gets fire out of coil when ign. first turned on and when I release the ign. key, but, not while starter is turn'n. I don't think these problems are related, but not sure.

Nov 18, 2006 | 08:50 PM

kjdunn

Thread Starter

New User

Joined: Sep 2004

Posts: 9

Likes: 0

From: north-east tx

Well, I figured I would get some answers on this forum,but I guess nobody has a clue on how to help. Thanks for take'n the time to look though.

Nov 19, 2006 | 04:16 PM

kjdunn

Thread Starter

New User

Joined: Sep 2004

Posts: 9

Likes: 0

From: north-east tx

Come on guys surely someone can give me some insght

Nov 20, 2006 | 06:48 AM

Sport45

Cargo Master

Joined: Apr 2003

Posts: 2,059

Likes: 426

From: Too close to Houston

Sounds like it might be hung up on the fast idle cam. The fast idle circuit is on the passenger side of the carburator. If it is adjusted too rich it may take a while to reduce the idle to normal. It also needs hot air and/or electricity to heat the choke housing to restore things to normal. If the hot air system was removed in an effort to "remove emissions junk" it could cause problems like you're seeing in cold weather (less than 74°F). Is there power getting to the electric choke while it's running?

Nov 20, 2006 | 12:17 PM

kjdunn

Thread Starter

New User

Joined: Sep 2004

Posts: 9

Likes: 0

From: north-east tx

Thanks for resond'n! If I bump the excelerator it will idle down, but, still too fast. It seems both fast idle and low idle are too fast. It appears the smog control equip. is still intact. I'm lean'n to a vacuum leak, but, have'nt found one yet.

Nov 20, 2006 | 11:48 PM

1987_f150

Senior User

Joined: Nov 2003

Posts: 283

Likes: 0

From: State College, PA

My 84 only has 1 spacer.

Nov 21, 2006 | 11:08 PM

kjdunn

Thread Starter

New User

Joined: Sep 2004

Posts: 9

Likes: 0

From: north-east tx

Thanks you for respond'n. I feel I have fixed my problem though. I got the idea from one of the threads on this site. "To help find a vacuum leak, spray ether or starting fluid on vacuum hoses and areas, if leak is there rpm's will change. Sure enough I found a hose on back of engine laying on top of the pipe to smog equipment that was cracked. Then I noticed the pipe had a hole in it, which got bigger as I cleaned it, ended up probably 1/2" by 2". Had to shape a piece of metal to fit over hole, glued it to pipe with JBweld. Then I was able to adjust my carb and time'n. !!!NOTE!!!: Be real careful spray'n ether on an engine thats runn'n, a spark could ignite fluid.
,