Loss of Power

Engine, ignition, fuel, cooling, exhaust

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BiggMike
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Loss of Power

Post by BiggMike »

I have a 69 F250 with a 360 and it loses power once you get up to 50 - 55 MPH. I have replaced the coil, points, plugs, and put a carb kit in. It is acting like it is losing fuel. I can release the accelarator and gently push it and maintain speed at 50 MPH but if I try and go faster it loses power.

Here are the specks on the truck
1969 F250
360
2100 Carb
Auto
Manual Steering & Brakes

Any help would be helpful.

Mike
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
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BiggMike
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Re: Loss of Power

Post by BiggMike »

I forgot to say that I just got the ttruck too, and it has done it since I got it.
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
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thebannister8
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Re: Loss of Power

Post by thebannister8 »

what do you mean by loses power....cuts out..stumbles or feels like it being held back.. :?
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BiggMike
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Re: Loss of Power

Post by BiggMike »

It struggles to stay running. It has a manual choke and I have tried to choke it to see if that would help and it doesn't.
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
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The Good Humor Man
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Re: Loss of Power

Post by The Good Humor Man »

I would check your vacuum lines, especially the one to your distributor for your vacuum advance.
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BiggMike
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Re: Loss of Power

Post by BiggMike »

did that but will double check again in the morning. Thanks.
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
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Re: Loss of Power

Post by fordman »

check the vacuum advance itself also. you have to provide it with a vacuum source to see if it operates. sucking air through the line can make it move.
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BiggMike
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Re: Loss of Power

Post by BiggMike »

Will do thanks.
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
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The Good Humor Man
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Re: Loss of Power

Post by The Good Humor Man »

I would also check around your carb for leaks. You can spray some carb cleaner, around the outside, and base, and if you hear it rev up you have a leak.
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BiggMike
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Re: Loss of Power

Post by BiggMike »

Double checked all vacuum lines and made sure the vacuum advance was working. Found a section of fuel line under the cab that was pinched and changed that to no such luck. Also tried the carb off my 72 F250 and it didn't help. Planning on draining and pulling the tank tommorrow to see if there is any thing in there and will also blow out the lines.
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
JEF199
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Re: Loss of Power

Post by JEF199 »

If you pull the choke out a little at a time while it's messing up and it dosen't help or hurt it then check the fuel presure. I just had a simular problem and I found that it had a pin hole in metal fuel line right where the rubber fuel line goes on.
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BiggMike
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Re: Loss of Power

Post by BiggMike »

Well I think I finally got the problem fixed. Not sure what it was but tuesday I drained the tank, blew air through the line from the fuel pump to the tank, removed the sending unit to inspect the inside of the tank and seen nothing stopping the flow, replaced the line from the pump to the carb, changed the plug wires, cap & rotor. Drove it today and had no problems at all. Now I just hope I can get the exhaust manifold bolts out without snaping them to replace the gasket. I just purchased the truck last week and getting all the bugs fixed before I put the body & motor on my 72 4X4 frame.
Mike

1968 F100 SWB project/parts
1969 F250 Ranger LWB 360/C6
1972 F250 4X4 Plow Truck LWB 360/4 Speed
1968 Fairlane 2Dr Coupe Project
1968 Mustang Coupe project, wifes car
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