Carb problems, mayb you guys can help
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
Carb problems, mayb you guys can help
Posted this in the C4 section 'cause it's on a C4, but they don't wanna help out with carb problems and I gotte get her running to get to the exhaust shop.
http://forums.corvetteforum.com/show....php?t=2138436
http://forums.corvetteforum.com/show....php?t=2138436
Intermediate
Joined: Sep 2008
Posts: 29
Likes: 0
From: Poteau Oklahoma
Is there a buddy or any body with another carb you could borrow to make sure that it is the carb? I have thought I had carb trouble before and it was the weights in the distributor sticking and causing the car to not idle and run like crap. It could be just a little piece of junk in the idle circuit. I know this isn't much but hope you can find your problem.
David
David
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
friend of mine,car ran rough,thought it was the carb. We could actually close off the intake to the carb(by choke or byhand) and the car would continue to run. yes, it was an manifold intake leak,which we found positive proof when removed the manifold. A skipped tooth would always act the same,morning or night,warm or cold. Make sure your dist. weights are moving freely too.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
A timing chain will jump a tooth when you stut the car off. Pull the dist. cap at TDC to see if the rotor is on #1 or if its off buy a 1/2 inch. You can reset the distributor to #1 and the might get the engine running so you can move the car but if the dist is more than an inch off I would try cranking it over. Because if it starts and the lifters pump up you may have a piston hit a valve!!!
Drifting
Joined: Apr 2008
Posts: 1,540
Likes: 51
From: Lexington Park Maryland
friend of mine,car ran rough,thought it was the carb. We could actually close off the intake to the carb(by choke or byhand) and the car would continue to run. yes, it was an manifold intake leak,which we found positive proof when removed the manifold. A skipped tooth would always act the same,morning or night,warm or cold. Make sure your dist. weights are moving freely too.
Pro
Joined: Jul 2002
Posts: 725
Likes: 1
From: copperas cove, texas
did you hook up the vacuum guage to the carb or the intake? BG has both ported and unported vacuum ports. dropping to 0 at an idle sounds like ported. I'm suprised that bg didn't give you better customer service.
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Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
The carb is a new (remanufactured) BG 650 Speed Demon w/ mech secondaries. I've got the distributor hooked to the ported vacuum source, and both the other vacuum nipples are plugged (the big one under the bowl and the small manifold source on the side). I was checking the vacuum with the gauge using a nipple on the manifold itself, so I can gaurantee it was real manifold vacuum.
Distributor is a new MSD run-of-the-mill distributor. I'll take it down and see if everything's moving properly.
At the moment the car is at the exhaust shop. Ended up trailering it there Sunday. When I get her back I'll start back in on the idling issue. Thanks guys.
Distributor is a new MSD run-of-the-mill distributor. I'll take it down and see if everything's moving properly.
At the moment the car is at the exhaust shop. Ended up trailering it there Sunday. When I get her back I'll start back in on the idling issue. Thanks guys.
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
Ok, I think I've got it figured out. Turns out the distributor was slightly loose, and has been wandering around on me. The timing's been getting steadily more retarded as I tune/run it which accounts for the wandering idle adjustments. This most recent time I suppose it got far enough out the car decided just not to run. At high revs the advance would keep it running, but at idle the baseline setting was just too far out. I've got it locked back down now and the car is running well again (for now). I still have a ways to go on this tune since it's barely even broken in, but atleast this current problem is solved.