1971 gt won't idle

[MichaelMuck]

Just pick up a 1971 opel gt that has the weber 32/36 carb on it. after replacing plugs,wire,rotor... after pumping the gas many times I can get it to start and run as long as I keep the rpm's above 1600. If it falls below that car stalls. these happens if car is cold or hot, also im at 4800 ft elevation. Any clues?

[greensmurf20]

i'd be pointing the finger at the carb not being set up right or a vacuum leak, probably at the booster or baseplate of the carb.

[jordan]

CAREFULLY spray some starting ether ("starting fluid") around where the intake manifold meets the head, and around the base of the carburator when the engine is running. If it revs up when you do this there is most likely a vacuum leak. though it could just be ether fumes going into the carburator the correct way, but if that's the case it won't rev up alot.

[NineLivesGT]

Same problem I had with my 71 GT. Was a huge vacuum leak, the car has a bad power brake booster, which I still haven't replaced. I pulled the power brake booster line and plugged it completely just down the hose from the carb, so it can't draw vacuum at all from the power brake booster. The stalling problem went away when I the plugged vacuum leak. Of course, now I have no power brakes, but the car only weighs 2200 lbs. I drove a 65 Impala (4000 beast) 117,000 miles with manual brakes, and manual steering, back in '75. For most cars back then, power brakes and steering were just a convenience item on the options list. Having driven tanks like that for years with manual brakes, manual brakes on my Opel doesn't bother me. Fixing the canister will be the last thing I'll probably do to the car. The only downside is that I have one leg like Charles Atlas, which makes one walk funny.

There could be other vacuum leaks at the base of the carb, as Jordan mentioned. Be very careful not to light yourself and the car on fire. High heat and/or sparks and starting fluid is dangerous. In the meantime, another trick is to loosen the distributor hold down bolt and turn the distributor VERY SLIGHTLY to the right, which will slightly advance the idle.You can usually find a happy medium by playing around with slight timing advancements this way where the car will at least run with your foot off the gas pedal, until you can fix all the vacuum leaks. I have a Solex, so I can't help you with setting the Weber idle. But try checking the vacuum leak route first, before blaming the carb. If that doesn't work, and there are no vacuum leaks, recheck the point gap and check the timing to be sure they're correct. If they check out, only then proceed to carb setting procedures on the Weber, which is available if you scan previous threads on Weber carb adjustment.

[Dmcbrass]

Before doing anything to the carburetor, make sure that the dwell (point gap) and timing are correct. I can always tell when my points are closing up because the idle speed will drop several hundred RPM.