The Stovebolt Site Forums The Shop Area Engine Shop Engine dies when coming to a stop.

Specs: 58' 235, Duel Cater YF's on a fenton intake.

The truck has sat for about a week, waiting for my new wheels bearings to come in the mail. It ran fine before that. I start it up to take if for a drive last night after finishing my bearings and it died coming to a stop at three or four lights. Other times it stumbled real bad and almost died before I could tap the accelerator to keep it alive. I bumped the idle screw up a bit to make it home alright, but it still stumples coming to a stop. Any suggestions? I did have to take apart my carbs and clean my plugs last month while out at my summer job. Plugs showed signs of running rich. I cleaned them and lowered the floats a little. Any one have this problem before?

I think you're chasing the right rabbit in considering the fuel level in th bowl but I can't see it changing by being parked for a week unless it had a borderline problem already.
Thoughts/questions;
what specs did you use for float setting initially?
unoriginal carb or engine mountings require unoriginal float/fuel levels.
did you check for a float taking on fuel?that could change the fuel level after a time.
is the carb oriented such that the fuel level on deceleration forces would make the float/fuel valve open and temporarily flood the bowl/venturi?
does it act better if the idle mixture is as lean as possible?
how did you balance the carb air flow at idle to make them equal?

I had a similar issue with my 55 1st series a few months ago. A friend of mine, old time mechanic, did a carb rebuild for me. Afterwards it would die at low idle and sputter just above idle. It only really ran at higher rpms. What we found is that the chemical cleaner during the rebuild knocked some build up loose, but didn't remove it and clogged up the carb so it only worked at high rpm when gas was being pulled through the carb a lot harder. Oddly enough we just tapped the side of the carb a few times with a wrench, firmly but not violently, and it worked out whatever was clogging the system.

Also, I suppose if you lowered the floats too much that could starve your engine, but I would imagine that would be a problem at higher operating speeds, not deceleration.

I can't claim much if any knowledge on your year of truck, but if you have a mechanical fuel pump in there, that could be failing to work, and since that does depend on rpms, it might also be the problem.

I hope this helps, I'm not genius, so take everything I say with a grain or two of salt.

Good luck ApacheFiend.

Well my summer job was working at a summer camp and I used what was at my disposal to set the floats. That means I had nothing at my disposal haha. So I kinda eyeballed them. I reset the floats because I was running rich and was fouling my plugs. What I don't understand is that after setting it, I drove for a couple more weeks around camp and did the drive home, 120-130 miles, with no issues. Drove it for a week here at home and it was fine. This just started last night when I took it off the jacks after the bearings got redone.

I think I will go back through the carbs and reset everthing. Balance them the best I can ect. Thanks for the ideas and suggestions SEMPERFInk and Enginenut! Does anyone have suggestions as to a good point to start the floats at lower than spec? This is on a 235 Duel Carter YF's. Start at a 1/16th of an inch? Thanks again!

Maybe the specified setting for floats is ok.If changes are in order it will be a cut and try exercise to find the magic spot.I think one of the main things concerning float level would be to try and make both the carbs the same--actually in every way and setting like the metering rods and pump.Have seen lots of problems from multiple carbs setups from dissimilar carbs trying to be paired.
Inspect those floats good for leakage or damage and dented floats are unusable.In your tuning you could at some point make a short run then remove both carb tops to visually check that the actual fuel level is the same in both carbs.Inspect the metering rod diaphragms well as one side is open to vacuum and a leak will be into the manifold around the normal metering and cause a rich mixture.
Metering rod adjustment is important to low and mid range mixture ratio and have an effect on economy and plug sooting at light loads.The main jets set the fuel ratio at full throttle but the metering rods decrease the size of the mains at cruse and high vauum conditions.
With throttle closed the stop screws need to be the stop--don't let the linkage hold one off the stop.
Both carbs need to come off idle together and have the throttle plates operate at the same angle all through the range.
With throttle closed the air flow through the carb throats needs to be very very near the same for smooth idle and off idle performance.
The best way to get this is with one of the gadjets like the uni-syn, a friend playing with english sports cars or motorcycles carbs can loan one.Many of the english cars with multi carbs to balance described using a piece of hose like about 1" heater hose placed to the ear and the other end offered to first one carb throat and then the other to hear the hiss of air around the butterfly and from the intensity decide how to make adjustments of the stop.I never developed my skill at this very well--I loved my unisyn to much.
One reason the idle settings are so sensitive is because the air and fuel normally delivered to give a proper idle by one carb is now cut in half because we have 2, and the fuel adjustment and the throttle plates are not designed to meter at that tight setting.I have seen it be necessary to work with the fit of a butterfly to get the air flow down.
I hope Hot Rod Lincoln can speak to these things--the serious racing mechanic has to develop a bag of tricks to keep a performance engine carburating cleanly all through the ranges.