72 SBB 350 bone stock, quadrajet and it use to run like a dream. One day I came to a stop light and it stalled, started it back up and at the next light it stalled again. Thought I may have some bad fuel, so I took a long drive and emptied out the tank. Put $20 bucks of Shell premium 92 octane (non ethanol), still was stalling when I stop in drive. The carburetor is a rebuilt one from "National carb" and like I said before it ran like a dream for 1.5 years. Now I'm stuck with this stalling problem. Here is what I've done so far to try to remedy it: - replaced the fuel filter - blocked the hose going to the charcoal canister - replaced the PCV hose and grommet to the intake - tested all other vacuum hoses and diaphragms all good - checked the carb vacuum and have steady 19 - set the dwell to 30 Then I set about trying to adjust my timing. Stock 350's according to the manual should be 4 BTDC at 650 rpm with the vacuum advance blocked. Well I can't even get close to that without the engine stalling, and when I get it close the engine has no power and is knocking and it dies whenever I put it into drive. I adjusted my distributor so the rpm's smoothed out and the engine would idle down to 650 rpm's. My timing mark shows to be about 30 degrees BTDC. The car seems to drive good, the stalling still happens but not as often. I know this can't be right, I was using the #1 plug wire (Front cylinder right side) for the timing light. I have done tune-up's on my car before and was able to dial in all of the spec's correctly, what the heck? Any suggestions out there?ou:
Read larry's power timing thread and set based on that. Even with the stock engine, it will run much better. On our stock 350, we changed the springs and weights in the distributor, and got the timing all in by 2500 or so. Made a big performance difference.
I think you picked up some crud and sucked it into the carb... I would have the carb rebuilt and before you drive it again remove the fuel tank and clean it as well.
You might be saying the same thing, but just in case............No. 1 cylinder is front left (driver's) side.
X2, all left/right references are made when viewing the car from the rear, # 1 cylinder is on the left front (drivers side)
We are talking the same, I did make my reference looking at the engine from the front. If I was in the drivers seat it would be on the left. Just to verify I was on the right cylinder I did hook up to the #2 cylinder and my timing mark was not even visible. I am using a new timing light, my 20 year old Sears finally gave up the ghost. I have the dial on the new light set to 0.
Also check your weights inside the distributor. Ours were stuck on the 350, so there wasn't any mechanical advance. Set the timing like the power thread says, and don't worry about what the initial is.
Stock timing specs are USELESS unless you have the original distributor in the car. The car is 38 years old. Unless you have owned it from new, and you know the distributor has never been changed, I wouldn't pay any attention at all to the stock initial timing specs. The only time the engine runs at the initial timing is at idle. Total timing and where it is all in has a much greater effect on how the car runs. The original distributor for a 72 350 is 1112109. It has 12-16* of advance built into it. Why they timed it a 4* BTDC is a mystery to me. You can go to at least 12* or more initial timing with that distributor, so it is a good one to have. Having said that, I would be looking at fuel level as a cause of your stalling. Either float level or fuel pump problems. I think that is far more likely.
On the float, you may be right, I am noticing the top gasket of the carb is wet after driving it for a while.
Then it may be flooding. That will stall the engine also. pull a plug and make sure they aren't fuel fouled.
Also check the rubber sections of fuel line along the frame, and up by the tank. They will delaminate from the inside closing off fuel flow, but look ok from the outside. Use your fingers or a pair of pliers and squeeze the hose and see if it feels squishy:Brow:
Well I'm going to try the performance timing this weekend, hope this smooths thnkgs out. It will be just in time for me to put the Buick up for the winter. ou:
It sounds like you sucked something into your carb. I bet you need a carb rebuild and also clean the fuel tank and start fresh.
Ok guys I'm a little late on this one but national carbs has rebuilt some carbs that haven't Dallas have post in the past about national. Yes they are the cheapest and they do rebuild carbs for autozone but they have been known to have a bad rebuild job if I could find the email between me and a craigslist user that had problems with his carb I would post it.
how many miles are on this motor ? symptoms sound very much like an old motor that has jumped a tooth on the timing chain......
plastic gears on chain have gone south. Breaker bar on balancer with cap off check the movement on the rotor.Move the balancer back and forth noting how much the rotor moves. Running good one minute,stalling the next something broke.Something to check at least
Recently bought a rebuilt 4bbl Qjet from National. Had a very similar problem. When first installed carb was fine then after a little driving all heck broke loose. Car ran like crap and wouldn't hold idle. Best I could tell there was some internal vacuum leak. If you plugged everything and covered the carb with you hands she actually ran better! Sent her back and I am waiting for a replacement!!
