72 Carb Issues?

[jethro66]

I have a 72 Cutlass Supreme conv. 97k miles. For years, always started even though it may be couple weeks in between starts, no issues. Recently, started, but stalls as I depress accelerator. Not a quick stall. Putters slightly in idle (can go minutes and then stalls in idle as well). If I depress accelerator it is doomed to stall quickly.

Disconnected inlet fuel line at in-line filter to rule out fuel filter, fuel pump, or plugged fuel lines. Fuel flowed fine.

Does anyone think it may just need a clean and rebuild or could it be something else?
Any troubleshooting advice?
Is a special breed of mechanic required to rebuild Q-Jet or can any Dallas mechanic do it?

I dare not take it out of the garage in fear of not getting it back up inclined driveway. No Christmas this year. Car blocks stairs from attic where Christmas decorations are stored.

Thanks,
JC

[Specman]

Did you remove the big fitting that goes into the carb too? There is a mini paper filter inside there that gets plugged pretty easy. Used to happen in my boat all the time.

Other than that, dirt in the carb bowl most obvioius cause. Still gets by because the filter is spring loaded.

Quadrajets aren't too difficult to do. Lot easier than a Holley I think.

[Oldsguy]

Look for a vacumm leak too. With one of those you can be running a lot leaner than you expect, not to mention screwing up your vacumm advance on the timing.

[jethro66]

Thank you for info.

Yes, removed fitting at carb and filter was clean. Initially, I thought it was filter or pump, but both looked and functioned good.

Vacuum leak may be issue. As I depressed accelerator, I heard a loud vacuum leak but cannot pinpoint origin of leak.

Thanks,
JC

[69oldsguy]

If you check all the externals and don't come up with the answer, start looking at the accelerator pump in the carb. If the accel pump fails you wont get a pump shot when you open the throttle, you'll lean way out and it will stall. Keep looking, you'll find it.
Kevin

[texasred]

Contact...heck, join...the North Texas Oldsmobile Club. http://clubs.hemmings.com/clubsites/ntexasoca/
Plenty of like-minded "Oldsiacs" that can help you with parts and info. Plus there's cruises, shows, and lotsa fun things. They should be able to point you to a good guy up there.

In San Antonio, I use Dan Sarvis Wblue70@aol.com. He's an Olds man, a racer (runs 11s in an iron head, QJet, 70 442), and rebuilds QJets. He took mine, rejetted, drilled the throttle blades, and had it set up so well that all I had to do was drop it on and drive it. We went to adjust it, but it was perfect as is! Reasonable price and he does it by mail, too.

C.J.

[jethro66]

Thanks guys. I finally figured it out over the holidays and she is purring now.

POINTS!!!!! Only needed new points.

Guess I focused too much on the fuel part of the triangle - fuel, air, fire.
When I saw a spark during spark plug check, I ruled out fire. Also, car would and did start up.

Hope everyone had a good Christmas!!!!!

[Eightupman]

I HATE how those $5 parts cause such a freaking headache....I would have sent you to change the accelerator pump in the carb with the info you gave.

Good fix!

John

[jethro66]

That's about right! Lots of time troubleshooting for a 1 hr fix (that included the drive to buy points).

My friend told me about a Pertronix electronic ignition. I may have to buy one.

[Oldsguy]

I am glad you found the problem. A Petronix kit would probably be a good investment. I have heard good things about those kind of kits. My son used one on his '64 394 and he actually saw an improvement on cold starts and a slight improvement on gas mileage. Of course, all that is subjective as he dind'nt conduct a true controlled experiment in the lab.

[Chumley]

I put a factory HEI in my 402 in my '72 Chevy truck a few years ago. Made ALL the difference in the world. Probably the single most efficient upgrade you can do ( for simplicity ) on these vintage machines.

Chumley