There once was a time when I could pull up to a signal and the engine would idle slow and smooth. I could take my foot off the break and it would almost not even roll forward. However now I have to have the idle set at 800 rpm vs 500 ( I think thats what it is) while its in drive to keep it from stalling, or i can have it a 500 rpm and just put it in neutral when I come to a stop. What has gone out of adjustment here? What is it that pulls the idle down when i come to a stop. Does the distributors automatic advancement control this? I'm running a stock 235 with a powerglide Thanks for your help
I did. I replaced plugs, points, condenser, wires, rotor, rotor cap, set points, set timing and dwell. Whats missing here?
Maybe the intake is leaking. Sounds like a vacuume leak, unless it smells rich. Were the plugs black?
Set your idle at the recommended spec 425 RPM. Any faster and the trans pump puts the load on it thats stalling it.
The idle is smooth when its out of drive, but i did check that anyway with starting fluid around the intake. the plugs looked pretty good when I changed them but I will check them again to see where I stand there.
ok 500 was just off the top of my head this has been 4 or 5 months ago. but I will check that. What pump is it that your referring to?
Also the cable from the throttle linkage down to the powerglide needs a little slack in it. If it's too tight it will act like you're describing.
Those 235 click away at low RPM's good. Temp changes with the season can make condensation inside the cap. Does it change as the engine warms up? Could it be a choke issue. Man being up here in the frozen north with salt on the roads has me a little jelous!! Wish I could drive my '40 Chevy........
Transmission. Early automatics were finicky about the idle and when the rpm started really engaging the "pull". A bit different from the Chevy Powerglide, but Caddys and Olds with the Hydramatic idled at just 375 rpm and you could sit in gear without holding the brake and it wouldn't creep. At 378 rpm it would creep and surge and want to die because it was over that point where it either wasn't or was engaging the transmission. I usta set the idle by putting them in gear with my foot under the front wheel and idling them down till it was no longer trying to run over me At 375 it looks so slow you can actually pick out a fan blade and fllow it around with your eyes. 425 on a chevy is a bit faster
It does it hot or cold. Speaking of cold I'm just leaving from work and its 44 degrees here tonight at 11:35
I swear it used to be like that. I could have held it back by just leaning against the hood. I do have the idle turned down as far as it will go and still idle smooth, I think it's around 450/500. Would anything else cause the pump to be putting a load on the transmission?
I think the pump he is talking about is in the transmition. I know nothing about the old cast iron powerglides if that's what you have... Good luck. I'm going to find something warm to sleep next to... Jeff
Yes. I have a '55 235 w/cast iron powerglide in my '46. Obviously it's not stock. Part of the linkage that runs down to the trans valve is aircraft style cable. You can see it easily below the exhaust manifold. In your pic it looks like a solid metal rod. A couple of things I've found on my setup: -I tried adjusting the small amount of slack out of that cable and found that it acted like you describe. -A couple of times that cable has become caught on the bellcrank and linkage so it wouldn't work right. I never had a problem with it until I started messing with it to make it "better". If you haven't changed anything that would affect it, it's probably not the problem. Just make sure it operates smoothly without hitting anything. If you have dual carbs or dual exhaust, the linkage may have been changed to clear them or rubbing on them might be causing your problem. Hope that makes sense. Tom
Had a chevy v8 doing the same thing, went looking for a vacuum leak around the intake and found nothing. Turned out that the old Quadrajet was leaking around the shafts. Bought a rebuilt Quad and it leaked vacuum even worse. Returned the rebuilt Quad, installed an Edelbrock Performer. Problem ended.
Well if it started after you did your tune up, i would double check everything. Are point gap OK? Is the pints OK. Is ignition wires connected in the right order? Are the cables OK? Is the rotor and cap OK? is the condesor OK. and so on.... Often you can use the old parts to find the fault, just because its new does not mean its OK, and works. Especially new old ignition parts. It happened to me more than ones that i had to replace the new stuff with the old parts ( im a flathead guy ;-) ) When you done the checkup above, i would walk down the other road with vacum problems and so on.
I'm having problems with my 235 idling also and wanted to know if my spark plugs are all black, does this mean I have a vaccum leak? Strange thing, it will idle fine and drive fine without the breather....any advice is appreciated! QUOTE=Dyce;2495669]Maybe the intake is leaking. Sounds like a vacuume leak, unless it smells rich. Were the plugs black?[/QUOTE]
If I remember correctly the bushings use to wear in the distributor and the dwell would change try taking the cap off and move the shaft side to side and see if it has a lot of play, and I remember a welch plug inside the carb that would fall out, but I don't remember if it was the 235 or the 230 it was probably 35 years ago when I use to work on them
My '47 Hudson was just doing the kind of the same thing with the Ford 390/2 barrel holley. Fought it for a week or two. Ended up being the check valve under the accelerator pump. The nipple that holds it in place had broken off so it wasn't checking. It would almost die when you came to a stop and as soon as you tried to accelerate it would die.
Stall test the engine against the converter, if it is very low stall speed the sprag has flipped in the converter. We used to see that some but not real common. Hoop
was dealing with the same problem in my 55 poncho turned out the needle was not seating. so the fuel was just filling up past the float bowl and flooding it out at idle
I have had a trans pot to go bad before and cause something like this. Also what hotrodbuildererny said about the bushings in the distributor. Check the vaccume pot also for leaks.
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