Lets is know how you made out with electrical, coil?? did you take the valve covers off and check the pushrods and rockers. I had an old mopar the bent a couple of the pushrods before right out of the blue. I'm sure that you had already check this, but I'm at work and don't have much time to reread you posts. Keep us posted. Sorry about the english and misspell words.
Harmonic balancer?
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efi pump has too much pressure, do you have a regulator on it set down to around 6-7psi? If not you are forcing too much fuel into the carb and flooding it. a better choice for a in tank stock style pump is for a mid 80's cfi pump that puts out about 13-15 psi then use a regulator to bring it down from there.
are you using a bypass style reg? did you put bigger fuel lines in? fi pumps are not designed for a carb app and have very high press. and low volume which is the opposite of what carbs need. if you are using a dead head reg you will kill the pump and get pressure creep past the reg. which will cause problems. just because you drove it for a month doesnt mean its right, sometimes it takes time to do damage. think of it like this, some people jump off bridges and some of those people live for a month afterwards but that doesnt mean its a good idea and the outcome is still the same youre dead in the water.
going back to a stock pump would be going in the wrong direction, stock pumps have even less volume and the same pressure as what you have now. The only right way to do it is to get a correct carb fuel pump and a minimum of 3/8" fuel line up to the carb. I know there are people who say its fine and they know someone or have done it themselfs but the reality of it is that in the end you never hear about the bad stuff since noone want to admit they messed up, rather youll hear that the engine builder did something wrong to make a valve or ring burn up or head gasket blow. heres some basic info, if say you are looking for 400 hp n/a from your motor it will consume 200 lbs per hour of fuel or about 33.3 gal. per hour. Now to get that past all the resrictions and 16 ft. of line then through reg and carb youre gonna need a bit more pump, which is why we run 140 gph pumps for that hp. If you look at FI pumps a 255 lph pump only puts out 67.3 gph or about 404 lbs per hr. which is enough to feed the motor with no problems but the difference comes in the way the fuel is handled and introduced into the combustion process. injection must atomize fuel into each port and that requires high pressures, its also more precise. A carb atomizes fuel in the plenum and each cylinder must pull air and fuel from a common area and get it down to the cylinders which isnt always easy. Im not gonna get into the rest, the best thing to realize is theres a reason there are 2 different types of pumps, its not a one size fits all deal.
As for would it cause a vibration, well it could if it is fouling out the plugs or running lean and burning things up. its really hard to have the answer online, all we can do is point out what sounds wrong and what to check and hope you tell us everything and check things. it could be fuel problems, spark scatter, arcing. If you can give me as much info about the ign. and carb setup as possible I can tell you where to look more.
As for would it cause a vibration, well it could if it is fouling out the plugs or running lean and burning things up. its really hard to have the answer online, all we can do is point out what sounds wrong and what to check and hope you tell us everything and check things. it could be fuel problems, spark scatter, arcing. If you can give me as much info about the ign. and carb setup as possible I can tell you where to look more.
This sounds like my problem last year. I wound up filling my oil pan up with fuel because when I rebuilt the carb, I put the wrong seal it (Holly 4150 metering block seal). The engine idled, but shook like hell when I hit 3k. It took me 3 days to figure out what was wrong. When I did, I had about 7qts of oil, and a gallon of fuel in the oil pan.
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If it is running insanely rich it will having issues revving and should even really be idling right at all. Sounds like the car is loading up from too much fuel do to the EFI pump.
Some good info..
http://www.allfordmustangs.com/forums/5-0l-tech/135024-efi-carb-conversion.html
Some good info..
http://www.allfordmustangs.com/forums/5-0l-tech/135024-efi-carb-conversion.html