Vacuum Problem?
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Vacuum Problem?
Hey guys. Hoping I can get some help here. I have a 1977 f-150 2wd, with a 351m and a c-6. All is stock with the engine, but just did a clean up with new gaskets. This has been a long process(8 years), but all is ready to go. Timing is set pretty close, truck runs, but stutters a bit until I give more gas. I have blocked all vacuum lines except from carb to distributor. This kind of stuff boggles my mind and really have no idea what goes where. So close, but feel lost. Is this a vacuum issue or is my timing not set right? Number 1 cylinder is at TDC, timing mark is around 8 degrees BDC, and the rotor is pointing at the number 1 spark plug contact on the distributor cap. Thanks in advance.
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No reason for blocking the vacuum lines, just not knowing what I am doing. Seems to be getting good fuel, brand new fuel pump as I wasn'teven getting fuel before. No, the carb hasn't been rebuilt. Playing with the timing, seems to help, but just wondering if the vacuum lines could affect rough running. I would assume so. Learning as I go.
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From: Isla de Muerta
It could be a lot of different things.
Have you installed a new fuel filter?
What carb are you running, is the choke set up correctly?
How's your distributor and it's components?
Vacuum leaks at the carb base, intake or any leaking vacuum hoses?
Do you have a pic of your engine that we could look over?
The vacuum system is a pretty important part of making these old trucks work correctly. Do have power brakes? What all did you unhook/block off vac hose wise?
Have you installed a new fuel filter?
What carb are you running, is the choke set up correctly?
How's your distributor and it's components?
Vacuum leaks at the carb base, intake or any leaking vacuum hoses?
Do you have a pic of your engine that we could look over?
The vacuum system is a pretty important part of making these old trucks work correctly. Do have power brakes? What all did you unhook/block off vac hose wise?
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This is the factory carb for this truck. No , I didn't change out the fuel filter as it does seem to be pumping good into the carb. The distributor looks in good shape but is original. I did buy a new coil though. This truck ran awesome before and I just tore into it to clean it up. Nothing on the carb has been changed. I will try to get some pictures up tonight and hopefully I could get this thing driving again. I appreciate the help.
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Joined: Nov 2003
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From: southeast Idaho
If you are going to unhook vacuum lines unhook all of them including the distributor. It shouldnt have any vacuum to it at idle anyway if all is well
If it starts running better hook them back up one at a time with it running so you know which one to look at.
But there are many things that could cause what you describe..
If it starts running better hook them back up one at a time with it running so you know which one to look at.
But there are many things that could cause what you describe..
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So of course, I didn't havd a chance to get pictures taken and posted(darn kid). I did find an illustration of where the vacuum lines go, so hope to get that wrapped up soon. I appreciate the ideas, questions and recomendations. I can put this stuff together but to understand is the key. I just want to drive it!
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