OK Oldtimers, put away your FlashScan and grab a dwell meter

[emarkay]

Well, maybe not a dwell meter, but we are talking Rochester 4 bbl Quadrajet, HEI ignition, weights and vacuum advance, and um, no computer at all.

Bizarre car trouble......
I have a 1977 98 Regency with stock Olds 350 and stock M4MC Quadrajet, 77K miles. About every 4th or 5th time, car will start up fine, and idle at normal fast idle speed, AND THEN either a minute or so after starting OR after pulling out from stopped position, car will stall and die. Nothing can be done to get a restart - no closed throttle, pumped or floored. - EXCEPT BY "PRIMING" - see below!

This has been a problem for me for many months and is finally becomming "chronic".

Carb rebuilt, fuel filter replaced, fuel pump replaced, lines checked, no apparent leaks, new plugs and wires, new cap and rotor,new rubber hoses, engine strong (no smoke), car well maintained.

****Clue #1: No fuel found in accellerator pump upon immediate inspection of carb at time of stalling. (That is why I did all the above repairs.)

When I rebuilt the carb, I cleaned it and found little evedence of dirt and no evedence of prior rebuild. I replaced needle and seat, and tripple checked smooth operation and float level, and check ball, and all gaskets, and did not see any OBVIOUS evedence of any internal leaks (Main discharge tube plugs seem to be a problem?), and used specs found in 1977 Olds Shop Manual. One other suggestion is a dirty "sock" in the fuel tank, but that doesn't make sense being so intermittant.

One other possibility I have seen is the "Siphon break passages" (may not be applicable to this MY car) and also, the vacuum breaks APPEAR to hold vacuum and function with a gradual (2 sec or so) return when vacuum is released. All vacuum hoses have been replaced on carb, and all others EMISSION hoses (cannister, EGR, THERMAC, DTVS,) are plugged. Timing is about correct (advanced to slight pinging at WOT under load), plugs wires and cap/rotor are new. Weights were rusty but are free.

****Clue #2: If I pour raw gas down the primary (a desperation move the first time this happened) THE CAR WILL START!!!! AND RUN FINE FOREVER!! Ocasionally I need to ""prime"" it twice to get it to stay running.

This has been happening for months now (winter and summer) and there is no pattern to it except with a cold engine and to pour raw gas down carb to get it to run!

HELP!!!

MRK

PS: I originally thought the carb rebuild fixed it - is "seemed to" but I finally got stranded big time yesterday, and am now getting frustrated!

[Ira]

Pressure gage at carb will tell you if it's getting fuel at cranking speeds. My 64 Ford van with leaky carb was a bear to start because the carb was always empty if it sat more than a day or two. After I put in a electric fuel pump I can fill the carb before trying to start it and it's fine. Definitely sounds like fuel.

If you don't have a pressure gauge, crank it a few times and loosen the fuel line at the carb. If fuel sprays out there's pressure and the problem is the carb, if not it's before that. Could be a leak in the gas line between the tank and the pump.

Ira

[Scoota]

Years and years ago, I had a customer with similar problem with a car, although it would do the same thing Hot or Cold, we checked everything, as you have.
We eventually found the problem; it ended up being a plastic bag shoved down into the fuel tank. Every now and then it would float past the pick-up and restrict the fuel. Someone had it in for him.
Anything’s possible although this may not be your problem as your car appears to have a problem cold.
Does your fuel pump have a return line back to the tank? It might pay to block it off as a test to see if it still does it.

Cheers, Scotty.

[joecar]

My wife's 1796 Datsun one time had a similar problem and it turned out to be that the filter element inside the fuel filter had proken off internally at the one end and every time it swayed off center it would restrict fuel flow and engine would either stall or not start; then when it centered itself, it would be just fine for a few days or a few weeks; happened hot, cold and in between.

[emarkay]

Years and years ago, I had a customer with similar problem with a car, although it would do the same thing Hot or Cold, we checked everything, as you have.
We eventually found the problem; it ended up being a plastic bag shoved down into the fuel tank. Every now and then it would float past the pick-up and restrict the fuel. Someone had it in for him.
Anything’s possible although this may not be your problem as your car appears to have a problem cold.
Does your fuel pump have a return line back to the tank? It might pay to block it off as a test to see if it still does it.

Cheers, Scotty.

No return line - and someone on another board suggested the "sock" - the filter on the fuel tank pick-up. Just need to think that cold start only and not predectable when it stalls, makes a plugged intake a small possibility, but I will look at fuel lines at tank and will also blow till I hear bubbles in the tank to 'clear' the lines and the sock this weekend.

MRK

[emarkay]

Forgot about this one - Mods you can delete it.

Problem was almost invisible cracks on the TOP of the rubber fuel line at the exit of the fuel tank, above the level of the resting fuel. Once fuel started flowing all was OK, but apprently that bubble and the suction flowing through the 'teeny-tiny' cracks prevented fuel from flowing. Priming the engine with gas (and the resulting start and racing RPM's) must have caused enough suction to overcome this tiny leak. Replaced the fuel line and never had a problem since!

Darndest thing in a car I have ever seen, and I have had about 15 of them...

MRK