Help! M915A1 Cummins 400HP dying!

[Autocar]

Anyone have any experience with a 400 HP Cummins dying after a long coast? This has happened three times now. After coming down a long slight grade with no throttle and coming up to a stop sign or freeway exit the engine just stops cleanly as if I shut off the key. I coast off to the side of the road and hit the ignition and it fires right up and no more problems. I don't have a clue where to look. Any ideas?

 

[hemichallenger]

Sounds like the fuel shutoff or losing power to it. Turn the screw on top of it. It will not shut off with the switch then but you will see if that is the problem.

 

[wreckerman893]

Were you using the Jake when it quit?

If you mash the Jake pedal down just before you stop this can happen.

Since I was so used to pushing in a clutch I caught myself doing this unconsiously in my M915.

Scared the crap out of myself a few times before I broke myself of the habit.

 

[R Racing]

My jake has a issue were it wont release from time to time ( even when I don't depress it, Think I have a electrical gremlin) . Have you tried setting it to low? Mine will do it on high and med but not low.Mine will sometimes do it at idle when I let off the throttle from a higher RPM.

 

[73m819]

My jake has a issue were it wont release from time to time ( even when I don't depress it, Think I have a electrical gremlin) . Have you tried setting it to low? Mine will do it on high and med but not low.Mine will sometimes do it at idle when I let off the throttle from a higher RPM.[/QUOTE]

Sounds like your MICO switch at the IP is sticking, also DIRT under the retarter pedel will cause the not releaseing, the switch under the pedal is nothing but a foot start button,

 

[R Racing]

I would agree. but its not suppose to come on unless I push the jake pedal . So I'm thinking Jake pedal switch. I did check both with a meter and they seem to actuate fine? anyone know were to find a replacement Jake pedal switch ??

 

[73m819]

i would guess napa, any foot start switch should bolt in, looks like evan a old ford tractor start button,

 

[Autocar]

I wondered about the Jake. The very first time it happened, I was backing up and turned around looking out the back window and I thought I might have hit the jake. I don't think I hit it on the coasts. I have the brake set on High. Where is the fuel shut off solenoid or the screw on top?

 

[fasttruck]

The knurled bypass screw id on top of ther fuel solenoid which is on top of the pt fuel pump on the left side of the engine where the throttle linkage ends. Normal running position is mturned out so the solenoid holds the valve open and when key is turned off allows in the close and stop engine. If turned on (clockwise) the screw holds the valve open all the time and with a 915 it will not shut off until the screw is reversed. With a 809 put in im high gear and stall the engine, 900s use the emergency shut off in the middle of the dash and reset the valve under the hood to restart engine.

 

[Autocar]

Thanks, I'll look for it

 

[73m819]

Anyone have any experience with a 400 HP Cummins dying after a long coast? This has happened three times now. After coming down a long slight grade with no throttle and coming up to a stop sign or freeway exit the engine just stops cleanly as if I shut off the key. I coast off to the side of the road and hit the ignition and it fires right up and no more problems. I don't have a clue where to look. Any ideas?

You know, I read this whole thread again, my 819 would do that, thought air, found no air, tried this, tried that, ended up being the electric fuel shut off solenoid, Will Wagner set me on the right path

 

[m16ty]

I vote for fuel shutoff. It's the simplest thing to test also.

 

[WillWagner]

Or too little throttle leakage. If you can't tell if the jakes are killing it, for a test, disconnect the throttle switch. If it still dies, turn the manual override in, then check it again. if it still does it, pay attention, if the RPM dips more than around 50 or so, it can have too much throttle leakage. Try the above stuff first..one at a time. If it still does it, PM me and i'll see if I can walk you through the adjustment for leakage.

 

[Autocar]

Will,
When you say the "throttle switch" do you mean the Jake brake switch on the floor?

 

[73m819]

Will,
When you say the "throttle switch" do you mean the Jake brake switch on the floor?

there is a micro switch on the Ip that the linkage contracts

 

[Autocar]

I've seen that. What does it do? I presume it tells the jake that the throttle is at idle and therefore it is ok to apply the brake?

 

[R Racing]

Yes thats what it does.

 

[bcowanwheels]

Sure your not sucking air in the fuel system ?

 

[Autocar]

If I was, I think it would not want to start. As soon as I touch the starter it fires right off.