Ok heres the deal..my 235 in my 53 is given me a problem i cant figure out..please help..it will start and run till it gets warm then it dies unless i keep the choke hrotpulled half way or the throttle slightly pushed..it will not run by itself when it gets to running temp..its a 54 engine bored forty over..fentons single carb rebuild..new plugs,wires,cap,points, and co.densor..it ran fine at first..any help please
sounds like a carb issue. i had a problem with one not running unless the choke was pulled. i rebuilt the carb and she was good to go. you said it was rebuilt. do you have the mixture set correctly?
check carb body to base tightness . grab top of carb & twist side to side-for some reason they loosen in that area-I've had two that acted like yours is acting &fixed both by pulling carb & tightening 2 screws
Good advice, I was just going to say that! It acts as a giant vacuum leak and the choke being on compensates for it. I used to see them loose on almost any Chevy 1 BBL I had in for a tune up. I would check for a gross vacuum leak first, just so you can see the difference. Let it run with the air cleaner off, place your hand over the top of the carb, if the idle picks up and it smooths out, you have a vacuum leak. Bob
Vac leak or plugged idle circuit. Make sure the throttle shaft holes aren't overly worn. If they are, you'll need to get a different carb.
My throttle shaft bushings were worn on mine did the same, also make sure the spacer block doesn't have small hairline cracks, seen that too
You have an exhaust manifold heat valve? If that is sticking and is not opening, it could make the engine run rough and not idle. Check that out too.
checked everything out, all the screws and bolts are tight, the spacer has no cracks that i can find..tried to re-adjust my mixture but doesnt seem to change anything no matter where i have it. pulled the breather and put my hand over the top and it killed the motor so i am thinkin there isnt a vac leak any were. i am goin to order a rebuilt one from the local parts house and try that. i need to get the ol girl back on the road. thankd for all the help guys, if a diffrent carb dont help i might bring this thread back up...lol
As d2 willys said CHECK the heat valve on the exhaust manifold for free operation . Stuck closed or partly so will cause your symtoms.
the ol 235 that I had was the valve in the exhaust manifold and the spring that goes on there. it was broken and I had to add a piece and spot welded it to the proper length and curled it up a little bit.
I maybe miss understanding, but mine only has the stock intake, i removed the exhaust and added fentins...is the valve u guys are talkin about in the lower part of the intake were the two were bolted together?