7710

[ken tudor]

will the return lines on top of the fuel injectors make it miss if they leak fuel. i put new pump an injectors an still got little miss when pulling her hard.
 

[Tx Jim]

Leaking fuel return lines will make a "mess" but not a "miss". Sounds as if it's a timing problem,bad injector or faulty engine cyl head valves.
 

[RodinNS]

They can let air in... so yes, could cause problems.
Do you know if it's getting an adequate supply of fuel into the pump?

Rod
 

[Bern]

Rod, this is one of those rare occasions where I am going to disagree with you.

The leak off lines on top of the injectors return fuel to the tank. Since this line has return fuel in it, a problem with this line should leak fuel externally, not allow air in. Even if air was to somehow get it that line, it should not affect the operation of the fuel system.

My comments assume an inline Minimec pump. I'm pretty sure my statement is also true with the CAV DPS rotary pump.
 

[RodinNS]

In principle I'd agree with you...
I'd not rule it out tho.
My line of thinking was more that it might allow drainback, but perhaps that's possible anyway.

I wish he'd just get someone to look at it instead of throwing more parts at it...

In my experience a 77 with the fuel staggers is almost always a dirty filter. If the lift lines leak then they won't start once the top tank is empty.... and usually if mine gets the staggers... it'll work OK for a while or until it's placed under a heavy load, then the missing starts.
This could also be a venting issue with the lower tank... a collapsed line between the tanks. A lot of things....
We're only armchair analysts from here.

Rod
 

[Bern]

My experiece on any Ford with two tanks that is starving for fuel has been plugged screens in the bottom tank.

I think Ford should have gone with a coarser screen once they went to the glass sediment bowl. Or better yet, nothing at all.
 

[ken tudor]

im about ready to get rid of it. i drain the bottm tank an no dirt at all in thr, i never fill the top tank just put 6 to8 gallon at a time in ,i have not adjusted the new pump yet, it sounds an runs good just dn a little on power an i can feel a little miss in high rpm
 

[RodinNS]

Well... my first course of action would be to FILL the top tank. That will then give you an idea of what kind of fuel flow is available at the filter and will provide supply enough to rule out a bad lift pump or some minor air leaks in the suction lines.
You can approach this from a fuel supply issue, atomization (injector) issue or a compression issue...

Rod
 

[DavidNZ]

Have you checked the injector pump timing? I had a 6600 that ran fine at 1500rpm and was missing at 2100rpm. Adjustment to timing fixed the problem.