i have a 77 f150 with a 400 in it. at the begining of the week it started to run rough. not wanting to idle and wanted to dog on take off. i figured it was a fouled plug or two cause it had a little miss to it. yesterday i changed the plugs and wire it didnt help right away. i decided to take it to a buddies shop to dig into it a little deeper. On the way there it fixed itself and ran good. Now today i drove it to a car show and it did fine there and back.

when i got home i park it for a little bit and then took it to the store it started right back into it. i have no idea what is causing in.

oh yeah its got a 600 cfm holley on it. any advice would be helpful

 

Check your Fuel Filters, another possibility could be a gunked up carb...if you check your fuel filter(s) and there is sediment, it could be your pick up tube in your tank????

 

its got a new fuel filter and its still full of fuel when it does it

 

I'd say a gunked up carb...do you have a spare laying around you could try?

 

no ill have to get one

 

Personally I keep an "extra" on hand...that way if something goes wrong with one (i.e...it needs to be rebuilt, or something like that) I am not dead in the water...came in handy about a year or so ago...went to pick up another Dent (roughly 2 hours from me), on the way back the carb started giving me issues, was able to swap the spare in, and finally made it back to the house...

If your going to pull it, might as well rebuild it...

 

today i took it out and down the road. i beat on it a little bit and it went back to normal. started to run better. but i do wanna get rid of the carb anyways its been nothing but trouble since the day i bought that thing. it was rebuilt before i got it and its pry had only 4000 miles on it.
i wanna switch from a holley to a new 1406 edelbrock

 

Love my Edelbrock...great carbs...

 

do i need to get a pressure regulator with one or am i good to go

 

Do you have a standard/stock fuel pump? Do you know how much pressure it produces? I have a gauge on my stock pump and it pushes 5-7ish...

 

yeah ive got a stock fuel pump. i just heard that if i put one on i would need a pressure regulator

 

Edelbrock carbs recommend 6 if I remember correctly...check the specs but I think that is correct...it wouldn't hurt to put a gauge on your current set up just to check what pressure your at now...I've got an inline pressure gauge right before my carb...

 

I have an issue with hard starts and rough running lately too on my stock '78 Motorcraft 2150. Believe it or not, I fixed it last night and found a messed up vaccuum actuator and some loose vaccuum hoses that the PO left open. Not knowing exactly where they went after coming off the carb, I had to resort to stuffing a large bolt in the end of each open hose, except for the one that goes to the distributor. (Mind you, this is after playing the "guess and check" game with the hoses and a vaccuum diagram.) The PO removed ALL the emissions crap from under the hood and blocked off the EGR valve with a piece of sheet metal, causing even the correct vaccuum hose setup to run like crap (if it ran at all). As I said above the only connected vaccuum hose is the one going to the distributor (which I want to say is the "S" port?) Mine runs pretty strong now, fires up the first crank every time without pressing the pedal to the floor at all. Sure I could track down the emmissions equipment and reinstall it, but here in wisconsin, people dont really care about emmissions, especially from these "ancient" trucks.

Just my experience, but my truck is due for a full engine overhaul and a new carb, even with 93,XXX on the odometer. But I bought it for $500 and it runs most of the time, so I'll just wait with doing a rebuild until I can roll in enough money to buy some better quality parts (headers, carb, pistons, etc.)