Alt question.

[TexasNomad]

Some thing in the pump broke and it flooded my engine with gas while I was driving home from work toasted that engine, I pulled my dip stick out and oily gas was dripping off it..

 

[1985 Ford F-150]

Well if ya buy a good one itll be fine. Ive never seen one do that and thats all that I run.

 

[Fellro]

What happens is the diaphragm tears, letting fuel into the motor. I had a carb needle stick once and do that too...It would seem possible too that you have a pinhole leak letting some air in before the pump. If small enough, it will still pull fuel, but also some air.

In reference to the plug gap, I have seen some chev's run anywhere from .044-.060. It may be higher voltage, but not so much that you can run just any gap, it still need to be in a range to keep things even. Even HEI's will not fire right when the plugs wear down too much.

 

[TexasNomad]

Well I changed the plugs right now and I must say its made a Huge! difference...
I'll replace the line next weekend...

 

[blackhat620]

Great info and thank you for the help, if I remember right when I changed the gas tank on my truck back when I first got the screen on the fuel pick up was crushed and ripped opened so I just take it completely off.. But check this out!
I have my fuel pump on a kill switch and when I kill the pump and the truck starts to finally die I turn the pump back on and both fuel filters will be full of fuel I can watch the filter before the pump and after a while it will pull a bunch of bubbles out of the tank and start doing the weird surging thing again..
Beats the hell out of me.

If you are getting air bubbles in the fuel filter then there is a leak in the fuel line leading up to the filter. Fix the leak and the bubbles will go away. This will solve the fuel surging and inconsistent fuel pressure problem.

 

[blackhat620]

Quick question...how on earth can his carb be starving for fuel, if he says it's running rich and blowing black? To me, those two symptoms just don't add up.

Simple, you are assuming that black smoke means that the engine is set rich, and this is not correct. Black smoke means that there is in-complete combustion taking place. Incomplete combustion can result from poor/inconsistent spark, incorrect engine timing, incorrect timing advance curve, air intake problems, varying carb float level resulting in inconsistent fuel mixture metering to name a few.

Tex has more than one problem here contributing to the poor fuel mileage and performance of his truck. From what information he has posted in this thread, he has low fuel mileage, lack of power, black smoke, extremely high base timing, too large spark plug gap, fuel supply problems and possibly and improperly adjusted carburetor. To isolate and fix the problems we must follow the basics of fuel, air & spark, set everything to OEM baselines in proper order and fix any problems with fuel, air and spark delivery.

 

[blackhat620]

...It would seem possible too that you have a pinhole leak letting some air in before the pump. If small enough, it will still pull fuel, but also some air.

Exactly

In reference to the plug gap, I have seen some chev's run anywhere from .044-.060. It may be higher voltage, but not so much that you can run just any gap, it still need to be in a range to keep things even. Even HEI's will not fire right when the plugs wear down too much.

I agree that engines will run with increased plug gap, and have done so myself on race engines, but it does take a stout ignition system and plenty of experimentation to find the correct increased gap that does not reduce performance.

 

[blackhat620]

I had a problem like that with them stupid elctric pumps. I swapped to the good ol mechanical and that filter stays full. Id maybe try that Tex.

I'm not a fan of epumps on these rigs either...putting a mech. pump on may help the fuel flow...but you still probably have a bigger issue. As for what you dropped on your pump, resell it...they seem to have decent resale value...or save it for a rainy day. You can pick up a carter pump from your local store for $20...or you can get a blinged out Holley like I did for $80.

Let's not get Tex throwing away good parts to install inferior parts. A mechanical fuel pump has far more negatives than positives and is a step backwards, no matter what year the vehicle was manufactured. Electric fuel pumps far are superior to mechanical pumps.

yeah I may try that but I paid allot of money for this Holley pump.

Tex Do Not trash your electric fuel pump, you will have far fewer fuel delivery problems with an electric pump then any mechancial pump.

 

[blackhat620]

Well I changed the plugs right now and I must say its made a Huge! difference...
I'll replace the line next weekend...

Glad to hear that properly gapped plugs have helped. Get the fuel line leak fixed, then check and set your base timing to spec. Then you can address carburetor adjustment as needed.

BTW what carburetor are you running on your engine?

 

[1985 Ford F-150]

Just sayin what worked for me when I had similar issues with my electric fuel pump.

 

[blackhat620]

Just sayin what worked for me when I had similar issues with my electric fuel pump.

Dan, that is fine, you had a bad electric pump that you replaced with a good pump. It would not have mattered if it was an electric or mechanical new pump since you had a bad pump anything would have been an improvement. That being said an electric pump that is pushing fuel is much more efficiant & consistant than a mehcanical pump that is pulling fuel. Also electric pumps will not leak fuel into the crankcase or suffer from vapor lock problems.