Injection pump problems

[CESMITH]

My 93 F350 7.3 ATS non wastgated turbo, Last weekend the fuel filter lite came on in the dash, no big deal (changed fuel filter ) now this:fuel filter lite comes on under hard aceleration,it takes fits of rough idling ( sounds like a SB chevy with a cam in it) every once in awile it acts like someone turned on the nitros?confused:I have checked for leaks in the return line ,could I have a return line pluged . or is the IP junk ! It has a tendency to stal if you dont downshift it at stop signs. I was told the govner is sticking.but it has done that since it was rebult less than 3000 miles ago. any body have any thoughts thanks ED

 

[Black dawg]

have you checked lift pump pressure?

 

[dyoung14]

The light comes on to tell you that you dont have enough fuel pressure, that wont happen if it was the ip, more than likely is the lift pump

 

[CESMITH]

IP pump

I think i did change the lift pump when i had the IP rebult, It could have craped out

 

[94turboidi]

I agree with the lift pump I have had those very same symptoms when I have had one go out.

 

[dyoung14]

could also be the tank selector valve being clogged and/or deffective, possibly even an air intrusion lots of things to check out

 

[icanfixall]

When the dash lite comes on your being told the filter is under vacuum. That means the injection pump is drawing more fuel than can come thru the filter. All the above postings are possiblitys. Check the easy ones first. Don't just start throwing money at it. Who rebuilt the injection pump and do they have a good reputation...

 

[hesutton]

I'd test the lift pump. Take the core out of the schrader valve on the fuel filter head. Hook up a pressure guage to that valve and crank the engine with FSS wire unplugged from the IP. It should be 4-6 psi. For volume, you should get 1/3 of a pint minimum with 10 seconds of cranking.

It sounds like you're starving for fuel. Gotta try and find out if it's the lift pump, or something in the tanks or the lines in between the tanks and the pump.

Heath

 

[CESMITH]

Lift pump

Yea , I remember now it did this before , I pulled the lift pump tonite , arm not atached to the diafram picked up a new pump on the way home . running again ! thanks everyone

 

[icanfixall]

The only way you can break the arm off the lift pump is to install it wrong. What you really need to be sure of is the arm fits under the cam lobe. If it ends up on top the arm will break off. Sometimes members find several arms in the oil pan when they overhaul the engine....

 

[CESMITH]

Lift pump

No the arm was under the cam , I had to check to make sure the wear marks were on top of the arm . The arm is still atached at the pivot but not atached to the diafram back inside the pump. darn shame it isnt that old and its made in the USA .got it at NAPA

 

[Diesel JD]

So did replacing the lift pump fix your problem? I hate those mechanical lift pumps forever and have had an electric pump for a long time.

 

[hesutton]

So did replacing the lift pump fix your problem? I hate those mechanical lift pumps forever and have had an electric pump for a long time.

X 2 Did it fix the issue? Probally did as it sounds like that lift pump was dead. I also love my electric lift pump as well.

Heath

 

[badasp118]

ok stupid question and i do not want to hijack a thread but you are talking about the mechanical fuel pump when you say lift pump correct? only way to learn is to ask I always say......

 

[icanfixall]

Yes... The mechanical fuel pump is also called the lift pump. They are one and the same thing... No dumb or stupid questions around here... Just dumb mistakes like.... A few years ago my rig was smoking a bit much so I turned down the fuel... Well it smoked worse than before... So I'm thinking I have a problem and just continue driveing. Then about 2 weeks goes by and me still thinking what I may have done wrong and it hits me like a fat girl falling off a bike... I turned up the fuel.... Me... A well know person around ehre make a mistake that simple... I posted what I did because its something others can laugh at with me. No matter who you are you are still capable of a mistake... Righty tighty... Lefty loosey... Works everywhere but the fan clutch nut.....