Got the new timing gears installed and new dist. The engine will start and run pretty smooth for about 2 minutes then it begins to sputter, lose rpm and misfire and then shudders to a halt. Tried setting timing and dwell but nothing will keep the engine running. Has anyone seen this problem? What should I look for as the cause?
Have you confirmed the electric fuel pump is supplying enough fuel? You should be able to run the fuel pump with a line into a bucket to measure the amount of fuel per minute that is flowing. Which carb and has the float level been checked?
Good point! I didn't consider the fuel pump since the engine ran marginally before the new timing gear install. The engine will run much more efficiently, so it stands to reason that fuel needs have changed. I have a Holley 2210 that needs work. Don't know the fuel flow requirements for my engine though. I'll check the pump flow tomorrow.
Fuel pump is working fine. This a.m. I experimented by turning both idle mixture screws completely in and with the choke held almost completely closed the engine idled for several minutes like that. Turned it off, adjusted the idle mix screws out about 1 1/2 turn open choke and it started and idled for a couple of minutes before running rough then just quit. I may be wrong, but I think my carb is shot. But I don't know enough about fuel systems to really be sure. Any help would be greatly appreciated. fixin it one part at a time...
Where are you located? Check the float level If the engine sat without running then the carb needs a rebuild most likely. 2 barrel or 4 barrel intake on this? I would consider a rebuilt carb... Send me a Private Message if you are interested in a rebuilt carb that is calibrated for the Buick 350. I found this old post you made: There are no "correct mounts" for your application. Who ever put this engine in must have customized something but it sounds like it may need more work to make it right. I dropped a Buick 350 into a 81 Silverado and the engine mounts were WAY off and I needed to do major welding to make it work and just sold the truck.... Where are you located? I would buy the truck off of you if I was close.
float is set correctly. did find a gasket that had blown outward. fixed that and tried to run it. Same problem, runs almost perfectly for a couple of minutes then starts to stumble, cough, shake, when I give it more gas it just sucks air and does nothing then dies. guess i need a new carb. can't afford a 4bbl so a 2bbl replacement is what i need. any suggestions?
I'm hoping my truck will run after installing a new/rebuilt carb. It's the only external part that has not been replaced over the last two years, except the alt. which I will swap out after she is running again. I found a couple of Quadrajet sources but I can't justify the cost because the truck itself isn't worth the cost of a Quadrajet. My question is there another option preferably cheaper 4bbl carb for a 1971 350 Buick engine. Anyone have an idea?!
Send a Pm to mark, he can likely do an economical rebuild a on a stock Buick 350 Q jet for you. In my opinion the fuel mileage savings alone is worth spending a bit of money on the carb: http://www.v8buick.com/member.php?13537-carmantx Otherwise if I was to bolt on a carb other than a Q jet I would usea spead bore holley which you might be able to find locally.
Another possible cause for a fuel delivery problem could be a gunked-up sock filter in the tank itself. I've had rough-run issues similar to what you're describing on a couple other old cars that I've owned over the years, and the clogged sock filter at the pickup in the tank was the culprit. I think the reason it is sort of intermittent is that when the engine is off the larger chunks of debris fall back off of the sock filter and move around in the tank. Then, when the engine is started again, fuel flows ok for a minute until the pump pulls the chunks back against the filter, blocking it completely. If your fuel level is low enough to do it safely, I'd recommend dropping the tank and inspecting. Hope that helps. -Chris
