How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Curtis B. Your Own Question
Curtis B.
Curtis B., Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 26748
Experience:  Technician turned service manager on multiple lines of trucks and engines, used in industry.
30244710
Type Your Medium and Heavy Trucks Question Here...
Curtis B. is online now
A new question is answered every 9 seconds

I'm trying to start an old Gradall, Detroit Diesel engine.

Customer Question

Hi, I'm trying to start an old Gradall, Detroit Diesel engine. Has been sitting for 8 years. It cranks and will fire when using starting fluid. But shuts off when stop using fluid. I changed fuel, changed fuel filter. New batteries. Cracked the injectors and the fuel pump works.
Submitted: 12 months ago.
Category: Medium and Heavy Trucks
Expert:  Curtis B. replied 12 months ago.

This the 4-71 , with knobs on the rocker cover? Do you have fuel coming out of the return line on the cylinder head?

Expert:  Curtis B. replied 12 months ago.

Have you removed the rocker cover and checked the injector fuel rack? It needs to be loose enough that it will move in toward the injector body and spring loaded to move back, If rack does not move, injectors are stuck!

Expert:  Curtis B. replied 12 months ago.

Would you have a manual pump you could hook to the secondary fule filter, the one past the fuel pump, and pump fuel into the filter and out the return line?

Expert:  Curtis B. replied 12 months ago.

My response shows as customer again!

Expert:  Curtis B. replied 12 months ago.

The injector rack needs to be all the way toward the injector bodys to start, but has to be free for the governor to bring engine back to idle. Or it will run away.

Expert:  Curtis B. replied 12 months ago.

Also consider this engine has an emergency stop and is a flap in the air inlet housing, before the blower. If it has been tripped, engine gets no air. But it must be open, or it would not start on starting fluid.

Expert:  Curtis B. replied 12 months ago.

Here is rack setting.

Related Medium and Heavy Trucks Questions