engine dies on bumps
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Junior User
Joined: Mar 2005
Posts: 66
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engine dies on bumps
86 f-250 7.5 liter 4brl
Runs great most of the time. but when going slow, like moving through a parking lot, hitting speed bump, or anytime engine is pretty much at idle and I hit a bump the engine will die. It will start right back up, and I have found that if I gas it as I hit the bump or pot hole that I will make it past said bump without the engine dieing. I am imagining that fuel momentarily sloshes away from fuel inlet in float bowls but perhaps I am wrong. When I set the carb I thought I had the fuel in the floats set at the right levels. Anyone got ideas?
Runs great most of the time. but when going slow, like moving through a parking lot, hitting speed bump, or anytime engine is pretty much at idle and I hit a bump the engine will die. It will start right back up, and I have found that if I gas it as I hit the bump or pot hole that I will make it past said bump without the engine dieing. I am imagining that fuel momentarily sloshes away from fuel inlet in float bowls but perhaps I am wrong. When I set the carb I thought I had the fuel in the floats set at the right levels. Anyone got ideas?
Elder User
Joined: Jan 2004
Posts: 561
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From: houston
Your float is probably too high. The fuel is sloshing out of the bowl and over the main jets. Whats happening is the engine is flooding out. With your foot on the gas, the engine is running fast enough to burn the excess fuel. That carb should have a sight plug in the side of the bowl. With the engine running, set the float so the fuel just wets the threads of the plug hole. Good luck.
Senior User
Joined: Jun 2004
Posts: 141
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From: Coal Creek CO
Could be a carb issue, I suspect electronics.
My 84 had a bad ignition wire, the green one coming from the ignition control module going to the coil was in bad shape. The insulation was like dust, I would at least check the wires and make sure you are not momentarily groundiing out on those bumps, a higher rpm just lets it pass on through.
This is just something to veryify before going into that carb, my opinion for what it's worth.
Jeff
My 84 had a bad ignition wire, the green one coming from the ignition control module going to the coil was in bad shape. The insulation was like dust, I would at least check the wires and make sure you are not momentarily groundiing out on those bumps, a higher rpm just lets it pass on through.
This is just something to veryify before going into that carb, my opinion for what it's worth.
Jeff
Fleet Mechanic
Joined: May 2005
Posts: 1,575
Likes: 11
From: Puyallup, WA
Check the main fusible link by the starter solinoid. I have had two 1986 models that while the fusable link itself was ok, the connector where it attatched the main harness was defective. Seems that Ford (and others) use a cheap butt connector of sorts. Because of the limited contact area for the electrical connection of this type of connector, heat builds up and causes corrosion. This causes further restance and more heat / corrosion.
Much like Aluminum wiring can do in a house !
Oh, these were EFI engines so I didn't have a carb to worry about.
Symptoms were - Random stalling at idle, engine would start right back up.
David
Much like Aluminum wiring can do in a house !
Oh, these were EFI engines so I didn't have a carb to worry about.
Symptoms were - Random stalling at idle, engine would start right back up.
David
Last edited by dmanlyr; Jun 13, 2006 at 11:25 AM.
