back to carb. troubles again. was running fine till a few days ago i had to put a new clutch kit in. it sat for 2 days without running while i waited for the clutch to be ordered. as soon as i got it back together i am back to the choke issue once again. runs smooth with full choke, remove choke the engine starts missing badly and occasionally backfires thru carb. and dies. also when it dies you can raise the hood and there will be a lot of moisture on the base of the carb. and even at times a thick frost. it has been in the 20's to low 30's here for the past few days any thoughts on what is going on. btw its a 250 with 1brrl.
sounds like the truck is getting too much air and not enough fuel... I have no idea of your carb history (or 1 barrel carbs for that matter) but if the weather is cold the truck may bot be getting a chance to warm up enough or possibly something is gumming up inside the carb from freezing temperatures, maybe some water in your gas or carb from condensation... have you tried gas line de-icer or carb cleaners?
It could be that the engine is not properly warmed up. Let it warm up to temp. then release the choke. If it continues to pop and backfire you could have a vacuum leak. Try this....Get a can of carb cleen and wash out the carb while the engine is running and with the RPM's up so it doesn't die. Spray around the base of the carb with the engine at an idol. If the RPM's change you have a vacuum leak. replace the gasket or vacuum line that is leaking. If all this fails you may have something stuck in one of the passages inside of the carb and you can try this as a last resort....Cross any 2 plug wires then start the engine crack the throttle a couple of times. This will cause the engine to backfire through the carb and should clear it of what ever is stuck inside. Make sure you don't have your face over the carb when you do this. Put your plug wires back where they belong start and adjust. You might want to replace your fuel filter too. Let me know how it works out.
Hmmm... I recall having a crack in my intake manifold that was also causing me problems with the old 292. I fixed the problem by installing a 350 V8
thought it just cold weather, but has been in 50's here for last couple days still having carb troubles. when sitting still with choke on will run smooth. driving must have choke on and yet it still stalls when you get on the gas, makes sort of a sucking sound through the carb. noticed that when i turn the truck off there is little to no fuel in the filter. just put on a new fuel pump and filter, same thing. any thoughts carb????
Try pulling the top of the carb off and check the float level. then check the needle seat and make sure there is no trash in the hole. You might try running a piece of tag wire through it or blow some air through it. Then check the main jet and see if it has something plugging it up.
ok did some trouble shooting this weekend problem is that carb is not getting enough fuel. when the fuel line is disconnected at the carb. the pump is pumping fuel like it should. when you connect it back to the carb its like there is back pressure or something and the pump is not able to pump the fuel from the tank to the carb. i have a rebuild kit for the carb plan on tearing it apart today and seeing if i can fix. any other thoughts?
as said above^^^^^ if that fails check the fuel pressure, maybe the pump is worn enough that it will only pump when not under pressure...
now gone from confused to just plain frustrated. Done a complete rebuild on the carb put it back on yesterday still same problem. It will run with the choke on but without it off it is starved for fuel. fuel pump is pumping, in fact new pump, fuel filter is in correct, fuel lines are clear, what the heck am i missing here???
This is a long shot... but are you using any older rubber fuel lines? is there a possibility a fuel line is collapsing under pressure partially blocking the fuel from getting to the pump? I've seen this before with cooling system but might be a similar situation with an older fuel line. otherwise it is likely a blocked passage in the carb or air leak as previously mentioned... either way carb cleaner should help you. could always find another carb and replace this one if nothing else works (I eventually had to replace the carb on my 292 before swapping to V8, the butterfly was worn and was leaking air in from the shaft)
Are you sure you don't have a vacuum leak like around the intake or possibly the hose that the pcv valve is on? Start it up and spray Carb. cleen around everything.
You know something else just came to mind, your gas tank might not be properly ventilated and be creating a vacuum. Just for the heck of it take off your gas cap and see if that helps.
Don i am running the idle mix screw about 1-1 1/2 turns from closed. last night i checked intake and all hoses, carb base etc. for vacuum leaks all is good. took the top off the carb last night, i think the reason the fuel is not pumping into the carb is because the needle valve is closed. however the fuel bowl in the carb is full so the float is raised closing the needle valve. this leads me to thing that the problem is the carb is getting fuel but not getting rid of it. i.e. a jet problem or something??
took carb off this evening ran some small wire through the vac ports and the jet cleaned real good with carb cleaner, made a minor adjustment to the throttle plunger, said lots of prayers for the thing and it is now working better, not perfect but better. can now open the choke about 3/4 way before it starts to stumble. i am thinking that may improve with driving. it does have an issue with the icing condition at the base so i am thinking that may have something to do with it not getting enough fuel when the choke is all the way open. if that is the issue it may clear on up once i drive it for 8-10 miles and get the intake real warm. anyway thank God it is running better. thanks to all for the suggestions.
It still sounds like it's lean to me. If you're going to drive it, keep an eye on the temperature gauge.
