Guys just want some opinions, my '89 shut off while ideling at a convenient store. All it does is crank, not one pop. Towed it to a guy down the street who works on large diesels (cuz I have no time). He said 2 injectors are bad. I need to find out what exactly he means by bad injectors (tips, cracked, ect.) But wouldn't the truck still start or try to even with 2 injectors bad? Sounds more like air is getting into the pump, or shut off solenoid is out. Just wanted some tips. I'm calling him tonight to find out all the details. Thanks in advance.

 

when one of our trucks had a bad solenoid we had the opposite problem, it wouldn't shut of, and even at that it was not long before the whole injection pump went out. I don't have any good answers for you.

 

I'd check the shutoff solenoid. Mine died on me idling at a red light before.

 

I believe I would fetch the truck home and make time to fix it.

You ?may? have some "bad" injectors, but I doubt that is your immediate problem.

You did the obvious and changed fuel-filters, right ??

Did you dis-able the grid-heaters and give it a squirt of ether while cranking ??

Did you put a test-light on the fuel-solenoid and ascertain that it was indeed getting power when the key is ON ?? still getting power when the key is in START position and engine cranking ??

If you have power at the solenoid, then remove the solenoid, GUT it, and re-install --- it should fire.

Of course, you will then have to use the manual kill-lever to shut it off.

If no power at the solenoid, then no need to GUT it, jumper a HOT wire straight to the solenoid and see if it fires.

If it fires with the jumper-wire, then there are about a dozen possibles in the fuel-solenoid circuit that could be the problem, including the key-switch.

 

Did you loosen the bleeder-screw at the filter and crank the engine ?? getting plenty of fuel ??

It is also possible that either of the short sections of rubber fuel-hose has rotted apart; one located between the frame-rail and lift-pump, the other between the frame-rail and tank.

If it will start on ether and then run, it is possible one of these rubber lines has developed a crack or split and an extended idle time allows the small amount of air to overwhelm the system, yet the amount of air be small enough to carry through when driving.

 

Ok, so found out the lift pump went out, the plunger broke inside the lift pump, no problem replaced the lift pump. Still didn't run smooth, so all the injectors are coming out and going to conestoga diesel to get rebuilt and rebalanced. But if somthing goes in the lift pump can a small piece of dirt or whatever go thru the filter, injection pump and clog an injector? I wouldn't think. Thanks for the suggestions guys.

 

Does it still shut off with the key? If the FSS shredded, it could get clogged up in a DV or something and cause it to be rough, or just air in the system unless you did crack all injectors after it was running to make sure all air was expelled.

 

Got injectors back from conestoga diesel, they pop checked ok and everything was in order and fairly balanced between all 6. They said the pressure was a little low, they were at 3,000 psi and bumped them back up to 3,500. So we will put them back in and see how it runs.