Later model float w/ scallop is 1-19/32" per fig. 1 and float drop is 25/32"
I don't have the factory Ford specs but the kit specs always worked for me.
Later model float w/ scallop is 1-19/32" per fig. 1 and float drop is 25/32"
I don't have the factory Ford specs but the kit specs always worked for me.
Come to a stop with the trans in neutral well before slowing down. Does it still stall?
I know you said you checked, but i had a kinda releasing but not entirely releasing clutch do this to me.
I always suspect the mechanical fuel pumps. They're troublesome when good quality and the aftermarket ones are rarely good quality. I'd put a fiver on the new pump helping your issues but I have no good reason for believing that; I just do.
Replace the fuel pump, reset tje float.
Still only stalls when brakes are applied from a roll. But not stationary.
What the ever loving berkeley???
I should add: stalls when hitting the brakes from a roll. In neutral with clutch released to take clutch drag out of tje equation. I also unhooked the booster and pcv to take tjose out
No change
If i partially block the throat of the carb, the engine picks up speed. But i cant find a vacuum leak anywhere.
And it will only restart after stall with a clutch pop or ether
Dusterbd13 said:If i partially block the throat of the carb, the engine picks up speed. But i cant find a vacuum leak anywhere.
Definitely sounds vacuum leakish. Have you tried spraying carb cleaner around the intake/outside of carb with the engine running to see if the RPMs pick up?
I does sound like you're leaking air. Only when hot........I'd be checking something attaching to the intake manifold somewhere. Feel around the bottom or use a mirror to make sure there are no weird openings that used to be attached to something. Make sure the bolts are tight. If you can get it running spray ether between the block and the intake top and bottom. I think there's a chance something is getting hot and moving.
EastCoastMojo said:Dusterbd13 said:If i partially block the throat of the carb, the engine picks up speed. But i cant find a vacuum leak anywhere.
Definitely sounds vacuum leakish. Have you tried spraying carb cleaner around the intake/outside of carb with the engine running to see if the RPMs pick up?
Along with that is there any slop at all in the throttle shaft? That was an issue with worn out Quadrajets.
I’m not too familiar with ford 300, but is there any chance it has a gasket between the intake and exhaust manifold under the carb?
On the Chevy 4.1 L6 I’ve seen the metal plate between the exhaust and intake corrode through.
But since it only happens after being under a load (when he exhaust would be hotter than idle if in driveway) I would guess it might be a small crack or leak between the manifolds that opens up when it gets hot under load allowing exhaust (or air) to flow into the intake manifold instead of drawing through the carb.
In reply to jstand :
Looking at intake manifolds on ebay, there does seem to be a gasket there. Or a plate. Or something. And its in a place that would burn off anything i spray before it got pulled in, because its an exhaust manifold. Wonder if i can see it with the carb removed?
In reply to Dusterbd13 :
I’m not sure on the Ford, but I’m pretty sure it was visible when looking into the intake on the Chevy.
But I haven’t worked on one of them since the late 1990s, so the memory is a bit fuzzy.
Does the '77 carb have a dashpot? It's designed to keep from stalling, it keeps the butterfly from shutting too fast at a stop and going rich.
No dashpot
Im trying to find clear pictures of the cavity and gasket between the manifolds now.
Just for fun have you done a compression test lately? Set up a vacuum gauge that you can see while driving (duct taped to wind shield). Use vacuum gauge readings to diagnose or eliminate issues. .
That may be one of the most useful things I've ever seen on the internet. Talk about your arcane knowledge.
I recall seeing a version of that chart in an old general auto mechanics guide (Chilton? Haynes?) that I had many years ago. I really wish I knew what I did with that book - it was very useful.
From what I'm reading....
Its not a fuel pump issue. Poor fuel delivery would show up during high demand, not low.
Its likely not a vacuum issue since a vacuum leak that big would show up or be obvious.
Its likely not a brake booster issue since they tend to just crack the diaphragm and its a problem all the time, not just when braking.
I'm strongly suggesting float issue. That would also explain why it stalls when you brake from a roll and not when stationary. Fuel slosh. That would also explain why you need starting fluid to start it again because its flooded. The ether has a much higher vapor pressure and will ignite when liquid fuel won't
Take the air cleaner off and get it running. Have someone keep it at a fast enough idle while you listen to the air. Let it go down to idle and I'm assuming it will die. When the air rushes in, a properly set float (no liquid) will sound like air being sucked like the vacuum hose at the dentist when its just sitting on the stand. If the float is set too high it will start sucking liquid fuel and sound like that same dentist vacuum, but it will sound like its in your mouth picking up liquid. That rattly "clicking" is liquid fuel getting sucked into the throats.
I have found that most carb rebuild kits come with fine enough parts, but horrible directions. I was rebuilding a 2jet for my boat and the directions said 3/4" between the horn and float which I knew to be incorrect. 2jets almost always are 3/8" so I set it using a 3/8 drill bit and it was fine. Don't always rely on the directions that come with your kit.
It should have a Carter YF or YFA on it yes? If so, throttle shaft play is an issue as well.
Other things I suggest: Try a $10 junkyard carb. Clean it up and install it for an afternoon. It may run like crap, but if the idle stalling is still an issue then you know its probably not a carb issue. I would also try taking the vacuum line off the brake booster and plugging it. Don't use a fully-threaded bolt, there is enough of an air leak down the spiral threads to cause problems. Use a clevis pin, or a shouldered bolt where the smooth part of the shank can be inserted into the hose. That will at least eliminate the possibility of a brake booster leak.
You can test for vacuum leaks with the ether as well which I think you probably already did. Just spray suspect areas and listen for idle changes.
Somewhere back didn't you mention that the carb was wet on the side with gas? Is that gasket leaking enough to effective lower the float level, causing the slosh stall?
Didn't read the rest, but are you sure the float is floating?
ultraclyde said:Somewhere back didn't you mention that the carb was wet on the side with gas? Is that gasket leaking enough to effective lower the float level, causing the slosh stall?
Or is the float level WAY to high, causing fuel to leak out the top?
We changed the float level both down and up last night. It didn't change the ussue, but resetting to the 3/8 that was reccomend here solved the wetting the sides issue.
The booster was capped off completely. At rhe manifold port.
I have been unable to locate anotger carb for a reasonable price.
Used ether last night, and had no conclusive findings. My last guesses are ignition module/coil (throwing parts at it), vacuum leaks at the intake somewhere that the ether is burning off before being sucked it (lors of labor without broken bolts, and it could get ugly quick) or a wiring connection that is breaking contact under negative g force.
There's a saying in the Volvo world where everyone is quick to blame the carbs or D-Jet: 90% of fuel problems are ignition related. And this sounds like it could be ignition to me. Are you 100% sure the timing is set correctly? And the mechanical advance is functioning properly?
A common way to check for intake manifold leaks is to spray carb cleaner at the junctions while the engine is running. If RPM changes, there's your leak. Which thinking about it, could be your problem, but it might be tricky to find the offending area.
It idles fine in neutral, not moving. If you hit the brakes, parked, not moving, does it stall? Used to power brake years ago to check for bogging, try to power brake it to see if it stalls. Does it have the stone filter at the inlet? Might be dirty cutting off fuel. Sounds like a float issue though.
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