Ford 7.8L cutting out at high rpm?

[Ace]

Well I have gone thru everything I can think of and checked everything but nothing seems to help. Its starting to look like a rebuilt injection pump is in my near future. I'll let you guys know when I get it going again, that is if I get it going again:beatsme Thanks for all your advice

 

[willie59]

Well I have gone thru everything I can think of and checked everything but nothing seems to help. Its starting to look like a rebuilt injection pump is in my near future. I'll let you guys know when I get it going again, that is if I get it going again:beatsme Thanks for all your advice

Yes, do let us know how it works out, always good to know with problems like this.

 

[Ace]

I have an update on the truck, I took it over to an old school truck mechanic to see if he could figure it out. It took him a few days but he thinks hes got it going. He found out the fuel filter base was plugged up. I changed the filters but never thought about the filter base itself being the problem.

 

[willie59]

Good news indeed! Could have had a piece of debris lodged in the fittings of the filter base. Things like that are not easy to find. Glad you got it sorted out.

 

[Ace]

Yeah I never would have thought that was the problem. Its amazing how you can spend hours upon hours diagnosing and trying to figure it out and it ends up being something simple like this. I'm glad it was'nt the injection pump! It was definitely alot cheaper this way!

 

[RVservice1]

another 7.8

Glad to see it is going for you!

I also have a 7.8 in an old L8000 similar to what you describe but the box was removed and a crane attached behind the cab. It drove in here two years ago and I hope to acquire it, but cannot get it started. The prime pump is gone, blocked off, and I have not been able to bleed the pump. They shut it off by closing the fuel valve as the shutoff solenoid is gone. I put fresh #2 directly into the pump, all injector lines off and still no fuel. I then pinched off the return line as I see it going back to the tank, tried again but to no avail.

Short of pulling the pump which I dread any ideas you have learned?:beatsme

I am going to back at it this am

Thxks

Larry

 

[CM1995]

Welcome to the Forums RVservice1!:drinkup

 

[willie59]

Welcome to the forum RVservice1. :usa

Have you verified the lift pump is delivering fuel under pressure to the injection pump?

 

[RVservice1]

Yes, I did, but I did get it to run. The stop lever on the pump was not open all the way. The hand lift pump is gone, replaced by a short plugged hose.I was low on diesel so I substituted WMO filtered and some Canola oil. Runs ok.

Rear air brake was seized on, loosened that, moved it to in front of the shop. Alt is not putting out, air is about 100 psi with a minor leak at the rad shutter solenoid.

Unit has a telescoping boom crane, 86 vintage, but I do not know the make or model could only decode a CM5001 number and a C11624 which might be serial num

I think it about 50' and a cable winch on it I guess with 60' of cable, 2 outriggers, controls on both sides. One control is for a pole puller/tamper but that is not on this crane.

Will let you all know If I get it and what I plan to do with it, all off road!

Thanks a lot

Larry

 

[MrKomatsu]

cam sensor?