It didn't run at all until I changed the filters and bleed the
system.

I'll bet it's either the fuel pump or else the return line. Either
of those fits the circumstances.

"Scott Vernon" wrote

Did it run OK after you changed filters. Air leak?

"Bart Senior" wrote
All filters are new.

"Scout" wrote

check your fuel filter.

I'd pull the filters again, just to be sure there isn't some restriction
there. Call me superstitious, but so many years working with fuel systems
has taught me that new means nothing.
Scout

"Bart Senior" wrote in message
et...
It didn't run at all until I changed the filters and bleed the
system.

I'll bet it's either the fuel pump or else the return line. Either
of those fits the circumstances.

"Scott Vernon" wrote

Did it run OK after you changed filters. Air leak?

"Bart Senior" wrote
All filters are new.

"Scout" wrote

check your fuel filter.

Why would the return line cause it to lose fuel when you open the throttle?
If the purpose of the return line is to return unused fuel to the tank,
theoretically there is less fuel passing through it as you open the throttle
up.
Scout

"Bart Senior" wrote in message
et...
It didn't run at all until I changed the filters and bleed the
system.

I'll bet it's either the fuel pump or else the return line. Either
of those fits the circumstances.

"Scott Vernon" wrote

Did it run OK after you changed filters. Air leak?

"Bart Senior" wrote
All filters are new.

"Scout" wrote

check your fuel filter.

Scout wrote:
Why would the return line cause it to lose fuel when you open the throttle?
If the purpose of the return line is to return unused fuel to the tank,
theoretically there is less fuel passing through it as you open the throttle
up.

Not necessarily. With a Detroit, yes, but other types of injector
systems do it differently. With our diesel (Ford Lehman) for example
there is almost no return at idle, the return flow seems to be
proportional to throttle setting (although it jumps when the load changes).

A blocked return line could cause the engine to die but it would be more
likely to surge or be unresponsive to throttle first (disclaimer- I am
not an expert diesel mechanic and never played one on TV)

Your advice about checking the filter again even though its new is right
on. Say Bart do you have a vacuum gage on the filter outlet?

Fresh Breezes- Doug King

Good points Doug.
Also, in many of the fuel pumps I've worked with, a severely restricted
return line will blow the pump seal.
Scout

"DSK" wrote in message
news
Scout wrote:
Why would the return line cause it to lose fuel when you open the
throttle?
If the purpose of the return line is to return unused fuel to the tank,
theoretically there is less fuel passing through it as you open the
throttle
up.

Not necessarily. With a Detroit, yes, but other types of injector
systems do it differently. With our diesel (Ford Lehman) for example
there is almost no return at idle, the return flow seems to be
proportional to throttle setting (although it jumps when the load
changes).

A blocked return line could cause the engine to die but it would be more
likely to surge or be unresponsive to throttle first (disclaimer- I am
not an expert diesel mechanic and never played one on TV)

Your advice about checking the filter again even though its new is right
on. Say Bart do you have a vacuum gage on the filter outlet?

Fresh Breezes- Doug King

DSK wrote in message ...
Scout wrote:
Why would the return line cause it to lose fuel when you open the throttle?
If the purpose of the return line is to return unused fuel to the tank,
theoretically there is less fuel passing through it as you open the throttle
up.

Not necessarily. With a Detroit, yes, but other types of injector
systems do it differently. With our diesel (Ford Lehman) for example
there is almost no return at idle, the return flow seems to be
proportional to throttle setting (although it jumps when the load changes).

I find that very strange Doug. I have a Ford Bowman and have a very
strong return even at idle. Also have a very neat system to bleed the
system of air.
Its a tank mounted above the fuel system that has a capasity of the
whole fuel system. If I get air in the system it get trapped in this
tank above everything else. On top of the tank is a valve for purging
out all the air. It's great for removing all the air induced while
changing filters off shore in a rocking boat. My return is just as
strong at idle as it is at full throttle. I have a simms fuel pump
what do you have? Perhaps the Bowman conversation is just far better
and stouter than your lehman conversion.

Joe





A blocked return line could cause the engine to die but it would be more
likely to surge or be unresponsive to throttle first (disclaimer- I am
not an expert diesel mechanic and never played one on TV)

Your advice about checking the filter again even though its new is right
on. Say Bart do you have a vacuum gage on the filter outlet?

Fresh Breezes- Doug King

DSK wrote in message ...
Scout wrote:
Why would the return line cause it to lose fuel when you open the throttle?
If the purpose of the return line is to return unused fuel to the tank,
theoretically there is less fuel passing through it as you open the throttle
up.

Not necessarily. With a Detroit, yes, but other types of injector
systems do it differently. With our diesel (Ford Lehman) for example
there is almost no return at idle, the return flow seems to be
proportional to throttle setting (although it jumps when the load changes).


I find that weird Doug, I have a Ford Bowman and the return is just as
strong at Idle as it is a full throttle. My Bowman conversion has a
Simms fuel pump what do you have on your Ford?

Perhaps it is because Leamans or not as stout and well built as the
Bowman conversions

Joe



A blocked return line could cause the engine to die but it would be more
likely to surge or be unresponsive to throttle first (disclaimer- I am
not an expert diesel mechanic and never played one on TV)

Your advice about checking the filter again even though its new is right
on. Say Bart do you have a vacuum gage on the filter outlet?

Fresh Breezes- Doug King

"Bart Senior" wrote ...
It didn't run at all until I changed the filters and bleed the
system.

Because the filters were clogged, or you had air in the system?
If the filters were clogged, the new one may have restriction already.
Did you inspect the rubber gasket? Do you have 2 fuel filters?

SV










I'll bet it's either the fuel pump or else the return line. Either
of those fits the circumstances.

"Scott Vernon" wrote

Did it run OK after you changed filters. Air leak?

"Bart Senior" wrote
All filters are new.

"Scout" wrote

check your fuel filter.

The filters looked ok, I changed them anyway.

There was air in the lines.

"Scott Vernon" wrote

"Bart Senior" wrote ...
It didn't run at all until I changed the filters and bleed the
system.

Because the filters were clogged, or you had air in the system?
If the filters were clogged, the new one may have restriction already.
Did you inspect the rubber gasket? Do you have 2 fuel filters?

SV

I'll bet it's either the fuel pump or else the return line. Either
of those fits the circumstances.