The 225 slant in my 62 valiant started stalling at idle without warning. Fuel pump, tank, and all ignition components are within 1000 miles new including rebuilt carb. Ran great last night but today will stall at idle unless I feather the gas pedal. All plugs look good and dry compression test is 110 to 115 psi on all cylinders. Tried tuning carb with no luck. Engine starts right up but immediately stalls unless you work the gas pedal. I removed the fuel supply fit tong from the carb and found the small I ring was deformed but also in the process the metering valve disappeared so I'm can't go much furtber until I get the carb right. Just looking for more direction as I move forward
225 stalling
- Thread starter Ranger333
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valiantwagonguy
Well-Known Member
Was the fuel pump brand new or new old stock? New ones use a diaphragm that will stand up to ethanol NOS ones didn't have that.I found this out in my 76 Aspen with a slant in it.I put a new old stock pump in and 1200 miles later I had the same thing you are having.I went nuts until I finally changed the fuel pump and the problem went away.
It's a new pump. Though pump and tank are new, maybe it's stopped up on the inlet side
valiantwagonguy
Well-Known Member
It could also be a vacuum leak in the advance unit on the distributor . Does it run after you get moving ok or does it bog down and feel like there is no real power when underway?
Slight stumble under way but mostly just won't idle. I checked vacuum advance and for other vacuum leaks already
valiantwagonguy
Well-Known Member
What kind of carb?
Not certain, it's a Holley 1 bbl
valiantwagonguy
Well-Known Member
I'd look at the carb .The float height . It may have picked up a small particle in the fuel and have a clogged jet .Take it all apart and squirt carb cleaner thru all the passages and jets . Could also be an issue with your points or a failing condenser or a failing coil . Could be a bad spark plug wire or corrosion in the cap where the wires plug in
My Barracuda had this problem for 20 years. Both my father and I rebuilt the carb numerous times, eliminated all vacuum leaks. Finally decided it was a tiny crack in the carb body where the idle screw seats. Swapped to a 2bbl Super Six setup and never looked back.
Carb is super clean, only issue is that messed up o ring on fuel intake, swapped with what I have on hand. I've found that if I hold the choke about 90% closed it idles perfect but need to open choke as I accelerate. So I assume it's a fuel delivery issue. I suspect the o ring is at fault or a failed pump
So, the little seal I pulled from carb fuel inlet should not have been there to begin with. I thin a piece may be in the carb somewhere. I do know accelerator pump puts out a nice stream. I'll rebuild the carb, and check fuel pressure from the pump.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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If it idles with the choke 90% closed, it's getting too much air from somewhere else. Think about it, she's running, so it is in fact getting enough fuel, to run, just too much air. This means your fuel system is working fine enough to idle. And since you can drive it and it seems OK,the fuel system seems to fine there too.
So the only issue you have is at idle. And Ima thinking it is sucking air somewhere.
Yeah the idle air bleeds may be not working right, but I'm going with a vacuum leak.
Yeah the point gap may be too tight, but I'm sticking to vacuum leak.
But, before you spend a ton of time on that, I would lash the valves. It wouldn't be the first time tight valves confused the issue. I use .013/.023 lashed at about room temperature. Mine runs like crap at the spec of .010/.020 hot lash.
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Thanks man, when I had it running today, the valves actually sound a little loose. I'll get a new carb gasket and check for leaks. I was thinking a air leak that large would be more noticeable and if a crack in the intake It would likely get worse when hot. It does stumble some on acceleration from a stop but it's also coming up from idle. Come to think of it, I had noticed that it would start right up first thing in the morning I could drive any distance, stop for a few minutes and it would start right up, if it sat for over 30 minutes, sometimes it would be a bear to get started, choke functions normal. When it acted up like that it seemed like it was flooding. My plugs are golden brown
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I guess in 62 they didn't have a PCV system. Is the carb also a 62 model?
Cuz if it's a post 68 it will be calibrated for a PCV. If you run a PCV carb without one, you will be too far up the transfers at idle, with the factory timing. And your mixture screws will be screwed in too far. This will make it idle, but lean at tip-in, causing a sag or hesitation. If you crank in some timing, then you can sorta get the fueling right, but then sometimes that puts the engine into detonation under load.
So the take-away here is, that if your carb has a PCV port, you should figure out a way to use it, and get rid of the road-draft tube...... or go back to the 1962 calibrated carb.
Cuz if it's a post 68 it will be calibrated for a PCV. If you run a PCV carb without one, you will be too far up the transfers at idle, with the factory timing. And your mixture screws will be screwed in too far. This will make it idle, but lean at tip-in, causing a sag or hesitation. If you crank in some timing, then you can sorta get the fueling right, but then sometimes that puts the engine into detonation under load.
So the take-away here is, that if your carb has a PCV port, you should figure out a way to use it, and get rid of the road-draft tube...... or go back to the 1962 calibrated carb.
Check the basics first. Put a dwell meter on it. Are the points in adjustment? Next, put a timing light on it. Where is the timing set? Start it up at night and look under the hood in the dark. Do you see plug wires arcing? Don't tell me they're new. CHECK THEM. New doesn't mean good. Also, look for any obvious signs such as a vacuum leak. Has it backfired recently? That can sometimes blow vacuum lines off and then you have a manifold vacuum leak. Look for the obvious first. Things like this are almost always something cheap and stupid.
For anyone following, the symptoms implied a vacuum leak. While I detected no leaks, upon disassembling the carb for cleaning I found a screw loose on the pump housing. So the vacuum leak was internal. Ol Betty is running great
now!
now!
oldmodlover
Well-Known Member
Dang. Just got back on. Had couple of things get in the way. Sometimes called "work " and "everyday life.
Was going to suggest vacuum leak.
I know, l know, after the fact, but hey, wuz tryn' to make a couple extra bucks to be able to fix my sh*t too. Lol!!
Glad you found the problem ! ! !
Was going to suggest vacuum leak.
I know, l know, after the fact, but hey, wuz tryn' to make a couple extra bucks to be able to fix my sh*t too. Lol!!
Glad you found the problem ! ! !
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