After new heads, carb rebuilt, plugs and wires new, and driving fine for a month or more, the 89 now starts, but immediately dies after you take your foot off the gas. Runs fine with accelerator being stepped on in the driveway. This started one day last week, out of the blue. I pulled the carb top, all is well, float not stuck, everything else looks fine.
I'm stumped. Any ideas out there?
04-17-11, 04:27 PM
Is the choke hooked up properly? Maybe it came disconnected? There may also be a vacuum break that helps with the choke that came disconnected.
04-17-11, 06:47 PM
Hmmm, does it stay running after it warms. I probably go after fuel pressure next.
04-17-11, 07:45 PM
Probably a choke problem or the way the carb is adjusted.
04-17-11, 09:36 PM
When you look at your carburettor, with the engine cold and off, is the choke plate open or closed?
This a carburettor off a 307. The front opening is for the choke. With the engine off and cold, that plate should not be open anymore than pictured. If it is opened, then the engine will suck too much air and stall.
Make sure all of the green (they may be a different color on your engine) linkages are connected and are secure. The choke mechanism is in that cylinder on the left side of the carburettor, and it may need to be replaced.
04-17-11, 11:52 PM
Who ever rebuilt the carb, I would have them take a look at it... My guess is thats where your problem is... Or you colud have a big vacume leak.. If you keep it running and listen for a leak...
I vacuum tested the pull offs before I reinstalled them, and they were fine. I can't find a bad hose or anything, but I'll try to listen for a leak again...
The choke plate is open just a bit, like it supposed to be. Like I said, it's a puzzle with all the work I've done to this vehicle over the last few months. I guess I'll double check for air leaks, and re-test the choke...
04-19-11, 10:10 AM
is your idle mixture off? I would have the carb tuned.
04-20-11, 02:24 AM
Change your fuel filter. It's cheap and usually solves the problem of low fuel pressure at idle or slow speeds.
04-20-11, 09:47 AM
It sounds like a big vacuum leak to me.