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1971 Cutlass w/ 350 4 barrel. I bought the car from Florida, & the prior owner's start instructions were to crank it a while twice, pump the gas & it started well. Idled slowly & rough til warm. It's a lot colder often in Wisconsin. I adjusted the choke, & have fast idle on the 2nd step of the cam. Car starts well & idles well also warming up. It drives away w/o stumbling. My only issue is I can't get it to kick out of fast idle. The cam moves through all of it's swing. It seems to "stick" up. It's been a few years since I worked w/ a Quadrajet ('71 G/S) & never has this before. I assume just working oil into the mechanism should be the proper solution. Any other ideas. The car is really falling together perfectly.
I would not use oil, instead spray the linkage with carb cleaner. Oil will let dirt and dust accumulate and cause more gumminess.
Since it won't drop off the fast idle cam, it sounds as if it is not adjusted properly or possibly the choke coil is not heating and opening as intended.
Having owned a '67 442 & a '72 442 while living in Northern Illinois during many cold winters these chokes take some time to "kick down" during the winter months - not at all like a modern car's choke or even an electric choke (replacement). Have you made any adjustments to the choke housing dial? Try adjusting the choke by dialing it in. The spring inside the choke housing might need replacement or you simply need to adjust the choke itself. Again though, they take some time to kick down during cold winter months but first make some attempts to adjust the choke housing dial. If it was in Florida, it most likely never really required a choke per se - certainly not like Wisconsin winters.
Yep these old cars certainly are different that cars now a days! When everything was new they worked good, as they got older things get iffy. A brand new clean choke spring works great, a 50 year old one with rust, not so much. The exhaust riser tubes get clogged, linkages stick, on and on. My 71 is set a little too high, it really roars but it seems better than it stalling out. A old high school buddy was over the other day when I was starting my Olds. He commented on how he had forgotten how the old carbureted cars were- stalling, high idle, etc.. He remembered it well though...
As said spray with carb cleaner and check the choke us coming off completely. We changed a few hot air choke coils on 307 powered big cars when they were about 20 years old. We also saw one set of rotten hot air tubes in the intake manifold. Both prevent the choke from fully releasing. This was in a shop, cars being driven in -40.
Thank you for all the advice. I did notice something funny from what's been said. My '71 has a 4 bbl w/ both hot air tubes & electric choke. Is this original? It seems strange. Car started perfectly this AM w/ temps at 40 deg. Ran OK warming up & seemed to drop out of fast idle. So far so good. I adjusted the choke cover slightly clockwise/leaner. The choke closes completely when cold. Then I also checked warm & it was fully open Electric choke is connected to an ignition circuit & works correctly.. Car get stored all winter so it should be OK for occasional starts. After it cools down I'm going to clean it really well again w/ carb cleaner. Hopefully it will continue to work.
Well I have to say that in 50 years of wrenching on old cars that is the first time I have seen electric and hot air both connected. Gotta ponder that for a while to determine if it would cause any issues or just be totally redundant.
Nope, not factory, a conversion. No Olds V8 came from the factory with an electric choke. The two terminal electric choke is a dead giveaway for aftermarket.
Last edited by olds 307 and 403; Oct 19, 2022 at 09:45 AM.
Would guess the small vacuum port in carb for the hot air choke would cause the electric to not work properly. So one would be fighting the other.
Is there a gasket between electric choke and choke housing? If so, electric wouldnt be grounded and not work.
Second wire is a ground wire. It definitely opens w/ ign. on. Originally they had it wired to the washer circuit up by the pump for positive. I didn't like that because accy. would cause choke to work. I rewired it so choke is on an ign. only circuit. It grounds through that funny little black box in the photo. It used to have several wires on it. Now none are left any more, only the one going to choke coil (ground). I think that box was something to do w/ pollution vacuum circuit originally. That stuff is gone now. Dist. vacuum hooks directly to carb, ported vacuum. Car started & drove well today, so am tempted to leave it alone for now. I'll try to get those numbers.
Vacuum port I was refering to is between choke housing and carb on hot air choke equipt cars. When switching to electric you need to plug that so electric works properly. Pulling hot air into choke housing may be messing with the electric coil causing it to be delayed or not opening all the way or closing all the way.
Carburetor #s I could find are #17054930 / 2135. Everything seems to work now, carb related. I'm surprised the shop didn't notice this when they were rebuilding the trans. He went over everything pretty well. The only problem left is hanging up at TDC when warm trying to crank. The shop checked the timing & found it advanced too much. They discovered the advance springs too weak. Advance was coming in at fast idle. Said initial advance should be 8 deg. but they set it back to 14 deg. due to weak springs. Car has started well for a week now, but hung up again this AM. Frustrating. It has a new starter, so I assume it's not that. Also new fuel pump. I turned the distributor back a tiny bit, & will see if that helps. I have 2 other 1970's cars & have timed them, so I have "some" idea, but am no expert. This car was owned by the same family in Texas through 2019, They had engine rebuilt sometime. Then the prior owner bought it & took it to Florida. He did a LOT of work on it. I have over 20,000 in receipts from him, but no engine work. This is the car where the Texas owners had an HEI installed. I discovered it was wired into the original ballasted circuit after checking wiring diagrams. That's fixed now. The carb issue is interesting also. Thanks for the comments.
Vacuum port I was refering to is between choke housing and carb on hot air choke equipt cars. When switching to electric you need to plug that so electric works properly. Pulling hot air into choke housing may be messing with the electric coil causing it to be delayed or not opening all the way or closing all the way.
They would not "fight" each other, they would both be heating the thermostatic coil and opening the choke. Having both operating at the same time would likely cause the coil to heat up faster than having just one or the other.
As for the air bleed in the choke housing, that small amount of air isn't going to do much; if anything it would slightly slow down the electric heat action. I did not plug it on my car when I converted to an electric choke and it works fine.
I had only a second to browse a couple posts & I have an errand to run. Question: Is the fresh air source metal tube (normally connected to the very top air port on back of carburetor) which feeds the manifold heat stove chimney hooked up to a fresh air source?
Do you mean a "filtered" air source? Even with no pipe attached from the U tube to the port on the rear of the carb, it would pull air through the U tube and heat it.
Do you mean a "filtered" air source? Even with no pipe attached from the U tube to the port on the rear of the carb, it would pull air through the U tube and heat it.
I did mean a filtered air source such as is delivered via the top port on the rear of the carb.
The timing with the HEI should not be 8 degrees. There are a couple of curves but most are 20 degrees at 1100. Get an advance cure kit. I haven't had issues with nearly 50 degrees at idle with slow cranking. Who knows how close that chebby truck carb is either.
Now I'm confused. I was talking about initial or static timing I believe it's called. Most cars I've set up in the past worked best around 10 deg. BTDC. I presume my guy meant 8 deg. BTDC & has set it at 14 for now. It was higher than that when he first checked it. Never heard of setting a car at 20 deg. for static timing. I doubt it would turn over very well. They're going to worry about fixing (springs) timing next year. I just want it to run OK for now. I'm too old to be racing around anymore. It shot up to 60 MPH pretty well today. I'm happy as long as it cranks well. How could the carb affect the engine cranking over?
The choke system seems to be working now. Starts well. It dropped out of fast idle all day like it should. The electric coil seems redundant, but works as is.
You have to remember that the initial timing setting is just a number that GM came up with for easy tuneup purposes.
The initial advance is actually total advance minus the mechanical advance.
So if your distributor has 24 degrees mechanical advance (points distributor), the initial would be set to 10 for 34 total.
If your distributor has 14 degrees mechanical advance (as most HEIs have), the initial would be set to 20 for 34 total.
As you can see, the initial advance for your HEI is different than the initial advance for the original points distributor.
Looking that number up on the internet shows a Chevy application, but it also shows a carburetor with the typical Chevy side fuel inlet and not a straight fuel inlet as used on Oldsmobiles.
Looking that number up on the internet shows a Chevy application, but it also shows a carburetor with the typical Chevy side fuel inlet and not a straight fuel inlet as used on Oldsmobiles.
So the carb number you posted for a side inlet does not match the pictures of your carburetor with a straight center inlet.
I was incorrect. I took a close up w/ my phone. The actual # is 17054938. Last # is an 8. Oops. That still makes no sense. I wonder what the heck was going on w/ that carb?
Now I'm confused. I was talking about initial or static timing I believe it's called. Most cars I've set up in the past worked best around 10 deg. BTDC. I presume my guy meant 8 deg. BTDC & has set it at 14 for now. It was higher than that when he first checked it. Never heard of setting a car at 20 deg. for static timing. I doubt it would turn over very well. They're going to worry about fixing (springs) timing next year. I just want it to run OK for now. I'm too old to be racing around anymore. It shot up to 60 MPH pretty well today. I'm happy as long as it cranks well. How could the carb affect the engine cranking over?
The choke system seems to be working now. Starts well. It dropped out of fast idle all day like it should. The electric coil seems redundant, but works as is.
The factory spec for many HEI is 20 degrees at 1100 rpm with the vacuum advance hose off and plugged. I have actually seen as low as 13 at 1100 rpm, my 81 Delta 88 was 16 at 1100 rpm. I say aim for 36 to 38 in by 3000ish rpm with the vacuum advance disconnected and plugged. You let the timing at idle end up at whatever is needed to achieve the 36 to 38.
Second wire is a ground wire. It definitely opens w/ ign. on. Originally they had it wired to the washer circuit up by the pump for positive. I didn't like that because accy. would cause choke to work. I rewired it so choke is on an ign. only circuit. It grounds through that funny little black box in the photo. It used to have several wires on it. Now none are left any more, only the one going to choke coil (ground). I think that box was something to do w/ pollution vacuum circuit originally. That stuff is gone now. Dist. vacuum hooks directly to carb, ported vacuum. Car started & drove well today, so am tempted to leave it alone for now. I'll try to get those numbers.
You might try bypassing the little black box to see how that effects the choke operation.
That little black box is not original and was likely added with the electric choke conversion. There are two such devices so you have one or the other.
HOLLEY CHOKE DELAY KIT P/N 45-267 (85R6161). It is a temperature sensitive resistor that will delay the choke warm up and extend the time the car runs at high idle when the intake manifold bolt it is attached to is cold.
The other device that looks like that has a few wires on it and is a little bit larger. I have seen it sold under a NAPA part number (2125?) and they called it a Choke Hold Relay. It has a very different purpose vs the Holley choke delay.
It also mounts on an intake manifold bolt so it can sense how warm the engine is. It has an unswitched battery lead that keeps powering the choke even if you shut off the ignition. It will keep the choke plate open until the intake cools down. Electric chokes can cause rough hot starts and this device prevents that and make the electric choke behave more like the hot air chokes.
I used to not like the hot air chokes as much as the electric chokes. I actually like their function over the electric as the coil can be quite tensioned cold but not really come on when warm. The same tension with an electric choke brings it on warm, which isn't always a good idea.
Last edited by olds 307 and 403; Oct 20, 2022 at 06:44 PM.
Same here. After having to install an electric choke due to the Performer RPM intake not having the exhaust port, I noticed a difference in choke operation compared to the hot air choke. The hot air choke just seemed to work better, and not need to be adjusted as much for summer / winter operation.
I've got a Ford van I picked up from my dad in Florida. The choke was not important, the air cleaner did not divert to over the manifold air when cold, and I think the heat crossover is more carboned up than a bag of Kingston. The heater core is bypassed. All of this matters in Indiana.
Point being, that stuff matters in the north so it needs fixing.
Now, why it has electric and hot air, I don't know.
I was never a fan of the divorced choke on my Dodge Van. Of course maybe it was more the POS Carter BBD carb that was even more of an issue. That style is only adjustable if you bend the rod. In the South, choke operation is not necessary, up here it had to be near perfectly set or starting in -40 sucked a lot.
Thank you for all the information. The discussion about timing was very informative. It's good to know the car has an Oldsmobile carburetor. I finally have the car working reasonably well. It sat all night, was a cold start at 40 deg. Idled well, smoothly now, & dropped down as it should. Drove away w/ no stumble. After it was warm it restarted w/o hanging up like it did at TDC before. I'd turned the distributor back a few degrees. It still accelerates very fast.
