when i run my car up to like anything above 4000 it will cut out really bad and lose all power, and then gain it again in a few seconds and then lose it again so i have to get off the throttle and idle for a little while and then it will do good until i run it up again i cant race anybody becuase in the middle of the race my car will start putt putting really bad and no matter how much gas i give it

 

Fuel pump? Fuel filter? Ignition?

 

im replacing the filter tommorow the car had a tpi motor and i bought it without any motor so i put a carbed on it and i am using the stock in line metal filter for the tpi. The mechanical pump is sucking through it pretty good, but the car sat whithout a motor and trans for i dont know how long so the filter probably is bad.

 

What did you do with the TPI pump when you put the carb on? Likewise what did you do with the distributor?

 

I bought the car with no motor or tranny so my motor has an accel HEI dist, and i dropped the tank and took out the fuel pump replacing it with a peice of hose about the same length as the fuel pump was. Its gat a mech pump on the motor now.

 

I replaced the filter today and the car is alive again it dosent cut out or lope when i am running it up. Besides loosing 5 gallons of gas changing it everything went great. I had to put vice grips on the rubber hose up by the tank to get the gas to stop coming out, but i already went from full to little over a half, i almost cried.
Mustangs watch out im back.

 

Scratch that is was doing good i took it on a 30 mile drive to pick my bro up and on the way back it acted up bad i couldnt go over 35 mph so i pulled off and revved it up a little bit and took it easy the rest of the way home and it did alright.
Fuel pump maybe

 

mine did the same thing it could've been several things so I took care of all of them and It doesn't do it anymore.

1)carb problems, I had an old quadrajet that wasn't really jetting just dripping

2) exhaust leak blowing on the fuel lines. This caused vapor lock and went away. I went from truck manifolds to headers and it went away.

3)at around 4000 rpms I understand the valves begin to float. I replaced the cam and needed to replace the valve springs anyway.

 

Don't forget most carbs have a small filter at the inlet. If the car sat without engine for long you might have sent some trash up to the carb. You didn't say what kind of carb you had or if it ever ran well with that setup. Sounds like it may be ignition related. See if it will run up when it is cold.

 

ive got an edlebrock carb and everything is brand new on the motor just built it and it ran great the first 600 miles and now it does this acting up. But it does run good when it is cold or even when it is beginning to warm up becuase i drove it aroung town when i replaced the filter and i thought it was fixed it ran great on the 30 mile drive to the school and on the way back it started acting up, granted i did get up to 110 but it still should do good thats what a built the motor for.

 

i too had problems with vapor lock b4....my car would run too hot (like 220-240ish) and when i would get on it it would cut out like mad......what temp does your car run at and how close are your fuel lines to your manifolds/headers....??

 

my car runs around 180 and sometimes it will go up a little bit but it will got right back down. Ive got shorties on it and the fuel line runs by the brack booster so it isnt really that close. My right side header now has a big leak it sounds like my motor is knocking really bad but it is the header leak could that cause it. Ive also got a stock fuel pump off an lg4 and it may not be fueling it properly either.

 

i just looked at my haeader and the back 3 bolts that hold it on are gone, I dont know where the went but the are gone.

 

to keep the header bolts from coming loose get some breslin split lock fastners trust me they work. you can get them from summit for $46.95 part #bpp-200-076