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3 Arm Wiper Setup
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Ford 6R80 6 spd
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Stall…vapor lock??
- Thread starter White Knight
- Start date
BOBS 2 68S
Full Member
The running while pumping the gas and the dies when idle sound like a vacuum leak
OP
OP
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- May 31, 2005
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I removed the aux tank… do I need to do anything with the fuel sender wires for the aux tank or just tuck them away
OP
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Sprayed with carb cleaner and clean with a soft brush. It will start right up and as long as you give it gas, it runs. Soon as you take your foot off the gas it stalls. So are we thinking new fuel pump is bad?
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- Nov 3, 2003
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Doesn’t sound like it. Still sounds like a carburetor issue.
Pour little gas into the float bowl vent. Not the throat of the carburetor, cause that’ll disappear in just a few seconds.
If you fill up the float bowl, the engine should run for several minutes just on that fuel being metered into it like normal.
If it still dies when you let off the gas, it has nothing to do with the fuel pump.
Pour little gas into the float bowl vent. Not the throat of the carburetor, cause that’ll disappear in just a few seconds.
If you fill up the float bowl, the engine should run for several minutes just on that fuel being metered into it like normal.
If it still dies when you let off the gas, it has nothing to do with the fuel pump.
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So I have a Holley 650 and decided to remove the front primary bowl, clean it, the jets and replace power valve… all back together should be good there. I took the secondary (rear bowl) … when I did, there are 6 screws (see photo) 4 are barely screwed in and 2 were loose sitting in the bowl. Are these screws supposed to tighten down… is it odd that 2 of them were sitting in the bowl? What do I do we these screws?
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Well, my guess, off hand is that, whether this is a carburetor or an articulated anvil, screws sitting at the bottom with empty threaded holes above, is a sure sign that they're supposed to be back in the holes. Truly, whether it's a clock, or a toilet seat.
And that any loose screw, still sitting in it's own hole, is supposed to be in that hole. Except that it's supposed to be tight.
Otherwise they're not doing their jobs. No company is going to spend money on screws that just sit at the bottom of an assembly, or uncontrollably loose in a hole. So they got there, presumably by not being put back correctly the last time it was apart.
I'm no Holley expert, but I would think that Holley probably has technical drawings and diagrams that should show (and even show in text) what those screws do, and whether or not they're supposed to be in their holes.
Looks to me like that is a "single-pumper" carb (vacuum secondaries I assume?) because instead of an intermediate jet plate (or whatever they're called) it's got a block-plate (or whatever it's called) that does not have secondary control circuits. So no jets, and no idle/air screws.
But you say it's a 650, which usually have mechanical secondaries, dual accelerator pumps, center hung floats, and all the usual suspects. Perhaps even a semi spread-bore base.
Got a picture of the whole thing? Or better yet, a part/model number stamped into the side somewhere? That picture has me very curious.
So yeah, put them back where it looks like they belong. Someone just left them loose or out when they put it back together.
Paul
And that any loose screw, still sitting in it's own hole, is supposed to be in that hole. Except that it's supposed to be tight.
Otherwise they're not doing their jobs. No company is going to spend money on screws that just sit at the bottom of an assembly, or uncontrollably loose in a hole. So they got there, presumably by not being put back correctly the last time it was apart.
I'm no Holley expert, but I would think that Holley probably has technical drawings and diagrams that should show (and even show in text) what those screws do, and whether or not they're supposed to be in their holes.
Looks to me like that is a "single-pumper" carb (vacuum secondaries I assume?) because instead of an intermediate jet plate (or whatever they're called) it's got a block-plate (or whatever it's called) that does not have secondary control circuits. So no jets, and no idle/air screws.
But you say it's a 650, which usually have mechanical secondaries, dual accelerator pumps, center hung floats, and all the usual suspects. Perhaps even a semi spread-bore base.
Got a picture of the whole thing? Or better yet, a part/model number stamped into the side somewhere? That picture has me very curious.
So yeah, put them back where it looks like they belong. Someone just left them loose or out when they put it back together.
Paul
Are all of the screws the same length? Did you aver have a fuel leak of any sort from back there?
OP
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Never a fuel leak. It is a model 4160 Holley 650 the secondary doesn’t have a accelerator diaphragm or power valve or jet screws, instead there is a metered plate unlike the primary that has a metered block, jets, power valve, accelerator diaphragm. All the screws are the same length and I was told they have the very simple purpose of securing the metered plate
Sorry my knowledge of carbs is pathetic, but could that plate being loose cause a vacuum leak? How long have those screws and that metering plate been like that? Also, it looks like in the pic. that the other two holes won't accept screws. Has that carb been rebuilt at any point and that plate may be from a different Holley, but serves the same function?
Could be an issue instead of it not getting enough gas that it may be getting too much gas at idle and choking out? Not sure if the screws are blocking ports but if the metering block is loose could be getting too much fuel past the gasket and into the TB and needs the throttle blades open for air to let it run. May be why it runs when giving it gas but not at idle. Just a thought
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All 6 are back in and tightened. The metered block in the secondary has metered holes on the bottom of the plate…. Made sure they are cleared and re-installed the secondary bowl. I have removed the primary again and replacing seals, power valve and accelerator diaphragm tomorrow and will see what happens.
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Sediment/trash in the fuel tank did this to my Bronco. I was stuck on vapor lock forever. Replaced the fuel tank, problem solved.
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Well I changed new 6.5 power valve, new accelerator diaphragm, adjusted floats so bowls stopped filling up to top, insure needles were clear. Started right, up, no leaks, floats working correctly idled a little high ran it like that for 5-10 minutes out it in gear and ran for 15-30 seconds and stalled. I’m ready to hit it with a hammer. Any input would be greatly appreciated and anything goes… you won’t hurt my feelings
I got this from AI:
Vacuum Leaks
Vacuum Leaks
- Cracked, loose, or disconnected vacuum hoses let extra unmeasured air into the engine.
- The engine compensates at a high idle, but the added load of putting the car in gear destabilizes the lean air-fuel mixture, causing it to die
Not sure if it helps or not, but it sounds better than "use the hammer"
I also am not strong in carburetors but will dive into them if forced. Just some rambling thoughts while I wait for a friend to get out of bed and message me.
Since it's a mechanical fuel pump is the carburetor design one that you can open the top and look into the bowl to see the current fuel level? If so I would do your above test of letting it idle in park the driveway for 5 or 10 minutes and then turn it off. Remove the top of the carb and make note or measure the fuel level. Then reassemble the carb and start it up and put it in gear until it quits. Then pull the top of the carb off and see if the fuel level is the same as the in park test or is the bowl now empty. If at the same level you might have something not carb related going on.
Might sound silly, but block the tires and with the engine off have somebody put the transmission in gear and back in park a few times while you observe the linkages. Is something hanging out that the linkage is catching on and possibly killing the engine?
Wait until dark and then have a helper start and put it in gear while you watch under the hood. Stand on the side so you don't accidentally get run over. Does the ignition or plug wires start jumping sparks to ground?
Does it have to actually get the wheels turning before it quits or does it quit just sitting in the driveway in gear but at idle?
Since it's a mechanical fuel pump is the carburetor design one that you can open the top and look into the bowl to see the current fuel level? If so I would do your above test of letting it idle in park the driveway for 5 or 10 minutes and then turn it off. Remove the top of the carb and make note or measure the fuel level. Then reassemble the carb and start it up and put it in gear until it quits. Then pull the top of the carb off and see if the fuel level is the same as the in park test or is the bowl now empty. If at the same level you might have something not carb related going on.
Might sound silly, but block the tires and with the engine off have somebody put the transmission in gear and back in park a few times while you observe the linkages. Is something hanging out that the linkage is catching on and possibly killing the engine?
Wait until dark and then have a helper start and put it in gear while you watch under the hood. Stand on the side so you don't accidentally get run over. Does the ignition or plug wires start jumping sparks to ground?
Does it have to actually get the wheels turning before it quits or does it quit just sitting in the driveway in gear but at idle?
