77 400 has me stumped

[gw33gp]

I had a similar situation like this with my race car when I was running the original stock fuel tank. I could get a couple laps on the track and it would shut down. It had loose rust inside the tank and it would plug the pickup in the tank. When it shut down the rust would fall off and I could re-fire. That loose rust would then slowly plug the pickup again with the engine running. I tossed the tank and put in a fuel cell and never had that problem again.

 

[19Walt93]

If you can get it to quit, try taking the top off the carb to see if there's fuel present. I have seen Duraspark modules produce what seemed to be fuel starvation symptoms- a 70's Fiesta would run all day unless you accelerated hard enough to open the secondary, then it would die down and quit. I beat my head on it for a while before trying a module as a wild guess.

 

[rusty ol ranger]

If you can get it to quit, try taking the top off the carb to see if there's fuel present. I have seen Duraspark modules produce what seemed to be fuel starvation symptoms- a 70's Fiesta would run all day unless you accelerated hard enough to open the secondary, then it would die down and quit. I beat my head on it for a while before trying a module as a wild guess.

There is a good amount of fuel there after i moved the float up. But i didnt check it right after it died...only after i had actually shut it off

 

[bobbywalter]

Yeah

 

[RonD]

Cut your fuel line shorter so it doesn't run higher than the carb

When you pump the throttle linkage does the Accelerator pump squirt gas into the engine?
If not the float bowl is low or new accelerator pump is bad

When fuel line is off put the end in a container and crank engine over(Remote start) and make sure the pump keeps pumping
There could be a issue in the FEED from the tank that builds up a suction in the line from pump to tank, so stop the fuel flow
Is it a single or Dual tank?

And yes, you could put a gas can on the cab and run a hose down to feed the carb, by gravity, to see if its a pump/tank feed issue


I wouldn't think spark unless power is being cut to the spark system
1977 could be using a resistor wire or ballast resistor for the coil, and it may have issues, you can "hot wire" the coil, run a jumper wire from battery positive to Coil "+" terminal

 

[rusty ol ranger]

Cut your fuel line shorter so it doesn't run higher than the carb

When you pump the throttle linkage does the Accelerator pump squirt gas into the engine?
If not the float bowl is low or new accelerator pump is bad

When fuel line is off put the end in a container and crank engine over(Remote start) and make sure the pump keeps pumping
There could be a issue in the FEED from the tank that builds up a suction in the line from pump to tank, so stop the fuel flow
Is it a single or Dual tank?

And yes, you could put a gas can on the cab and run a hose down to feed the carb, by gravity, to see if its a pump/tank feed issue


I wouldn't think spark unless power is being cut to the spark system
1977 could be using a resistor wire or ballast resistor for the coil, and it may have issues, you can "hot wire" the coil, run a jumper wire from battery positive to Coil "+" terminal

Good idea on cutting the fuel hose shorter. Didnt think of that.

Yes accelerator pump is working.

I havent tried pulling the hose off and cranking on it after i changed the pump. Ill do that.

Ill set a can on the roof and try gravity feeding it. Wont hurt anything.


Like i said ive had alot of experence with these but ive never had a spark box give up on me. That was my main question really was if yall thought i was chasing a fuel issue when it might actually be spark. I know they are basically an early version of the ignition module just didnt know if they could fail in bizzare ways like the TFI ones.

 

[PetroleumJunkie412]

I'll give ya tree fiddy.

 

[Curious Hound]

I'll give ya tree fiddy.

But it's only a 250. You're offering too many.

 

[rusty ol ranger]

I'll give ya tree fiddy.

Sorry dude....even broke down this truck is not going on the block lol

 

[19Walt93]

The bowl can be empty of fuel and the accelerator pump will still squirt once or twice, take the top off immediately after it quits and look. If you want to just throw parts, I'd swap the needle and seat and set the float level to spec. A new needle and seat can stick. From the Fairmont vibration diagnosis guide: new doesn't mean good, new means new.

 

[85_Ranger4x4]

Holley Sniper EFI 550-510 Holley Sniper EFI Self-Tuning Kit - Shiny Finish

Holley just brought EFI within range with Sniper EFI! Introducing Sniper EFI! Sniper EFI is economically priced so you can have all the benefits of Fuel Injection and still have money to finish or upgrade the rest of your ride! Perfect for street rods, muscle cars, off-road trucks, or nearly...

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[rusty ol ranger]

Holley Sniper EFI 550-510 Holley Sniper EFI Self-Tuning Kit - Shiny Finish

Holley just brought EFI within range with Sniper EFI! Introducing Sniper EFI! Sniper EFI is economically priced so you can have all the benefits of Fuel Injection and still have money to finish or upgrade the rest of your ride! Perfect for street rods, muscle cars, off-road trucks, or nearly...

www.holley.com

No

 

[PetroleumJunkie412]

No

Yes.

 

[rusty ol ranger]

Yes.

You buy it and install it.

 

[RonD]

Fuel injection is the same at Auto Driving cars will be

No fun, at least with a carb you KNOW you are still a mechanic(weekly), and will be until the day you die, or you sell that vehicle