[grebmohr]

Spent some time checking and tracing leaks on my '90 Diesel. I seem to have all of them fixed and starting is alot easier- still have occasions when the motor kicks and then stalls immediately. Then starts fine. If I depress the Schrader valve on filter house there can be some air expelled before I get a steady flow of fuel. What would casue this?

 

[cdnsarguy]

Air is entering the filter header from somewhere........ Try clamping off the line to #1 injector from the filter header........ then do some starts and driving. Sometimes the check valve in the filter header does not work and allows air to return to the filter from the injector return lines.

Visit my photo link and search for the steel line seals ....... they are under the cap nuts on the lift pump to filter connection also the filter header to IP steel line connections.

 

[grebmohr]

Air is entering the filter header from somewhere........ Try clamping off the line to #1 injector from the filter header........ then do some starts and driving. Sometimes the check valve in the filter header does not work and allows air to return to the filter from the injector return lines.

Visit my photo link and search for the steel line seals ....... they are under the cap nuts on the lift pump to filter connection also the filter header to IP steel line connections.

I have suspected that check valve but have not replaced it yet. My wife does not understand that a $500 dollar truck with a blown transmission costs more that $500 total to get road worthy again.

I got some diesel safe PVC clear from Mcmonster-carr. Do you think I can road test with that inplace of the black line to get everything up to temp then shut it off and wait for the bubbles? the clamps wont hold on the smaller OD. what kind of pressure are we dealing with in the return circuit? According to the Ford engine manual, that line,to #1, arrows point towards the filter header. Any leads on the lift pump seal? Also does the IP feed line have a rubber crush seal on the top and a Flare on the IP side? Or is it rubber both ends...I am certain the lift pump side is an inverted flare fitting.

Lots a questions for a small post. Seems like the filter/separator header was an "oh crap, we forgot something" moment for Ford.

Transmission Parts tab- 500.00+ I lost some receipts.
Rear wheel bearings and seals 100.00
Brakes with Cylinders front, rear kits, pads and shoes,machining 180.00
PS pump rebuild kit and hoses 65.00
Thermuskrat/gasket 1st time Napa 32.00 2nd time Ford 28.00- DOH!
Spending money on "Bertha" but man, I love this truck! I offered to pull the bumper off a friends '72 Ranger... he declined the offer... :-(

 

[trampsdieseltruck]

i put 2 clear return Fuel_Line on me truck when i was having problems.when the truck is idling i was seeing bubbles in the lines.i would turn the truck off and there was fuel in the clear lines but when i checked 3 hours later the fuel was gone.turned out to be the fuel sending unit in the tank.i had the sending unit rebuilt for $70.truck runs good now,the clear lines have been in the truck for 15 months now.

 

[grebmohr]

i put 2 clear return Fuel_Line on me truck when i was having problems.when the truck is idling i was seeing bubbles in the lines.i would turn the truck off and there was fuel in the clear lines but when i checked 3 hours later the fuel was gone.turned out to be the fuel sending unit in the tank.i had the sending unit rebuilt for $70.truck runs good now,the clear lines have been in the truck for 15 months now.

What was bad in the sending unit that caused your problem?

My truck runs well it's just that I have to purge a hammock of air when cold starting. and sometimes just a paper clip of air when warm.

"Where did you get those units of measure?"
"Mar-y"

 

[trampsdieseltruck]

there was a pinhole in the metal line at the top of the sending unit.if your truck has no major fuel problems then i would not worry to much about it.

 

[grebmohr]

Anyone know if there a check valve in the outlet extension of the lift pump?

 

[grebmohr]

I think I have solved the problem. I had removed the heater unit and sealed in a flanged aluminum plug which I then secured with an aluminum cross bar, threaded into the plug to hold it together while the sealant dried. (this repair was flawless and permanent)
In all my attention to that fix, I was negligent in my sealing of the 1/8 NPT threads on the filter header. It was a situation of more air sucking in than fuel was leaking out. Took me a week to notice there was any moisture on the header at all. Now it kicks off before I hear the 3 Rev start- awesome!

Thanks to everyone for help.