Community Forums

Craig1960 · 09-05-2021, 08:58 PM

While on our trip when we stay a night or two somewhere the m/h has been hard to start each time, to the point today I had to find the problem to get it going. The fuel solenoid wasn't working so I pushed it up and the m/h fired right up. After that we only shut it down for a few minutes while checking into the next campground and it fired right up with no help this time.

My question is two part I guess, first is when I pushed the plunger in, it came back out a bit before it stopped (maybe 1/2" to 3/4", I can't say for sure because I didn't think about until later)but still started fine, does it have to be all the way in and would I be starving it for fuel if it wasn't in all the way?

Part two is does anyone have a part # for it. 98 Monaco Windsor with 8.3 Cummins. It's dark now so I won't be able to get any other numbers off the engine until daylight.

Skip426 · 09-05-2021, 10:56 PM

The fuel shut off solenoid on a P-7100 injection pump , is two stage ; pull and hold ; the pull portion gets a signal from the starter motor ( via a relay )when the engine is cranking and the hold from the ignition switch.

So bad power through the relay to pull the solenoid has to be investigated , before replacement .

Here's a diagram .
As far as parts are concerned , I believe all the P-7100 pumps used the same solenoid , so one listed for the same vintage 5.9 Cummins will be the same .
94>98 1/2 Dodge/ Cummins.

Craig1960 · 09-05-2021, 11:19 PM

Thanks, I will be checking the wiring when I get home but was just trying to get a part # in case that's what it was which should be easy to find with the info you gave me.

Now I'm wondering if I need to zip tie it up for the trip home or if it's ok to just push it up like I did today.

Skip426 · 09-05-2021, 11:28 PM

If the solenoid arm is tied up ; you can't shut the motor off with the key .

You'd have to cut the zip tie. Not much fun on a hot engine .

Craig1960 · 09-06-2021, 12:21 AM

Quote:

Originally Posted by Skip426

If the solenoid arm is tied up ; you can't shut the motor off with the key .

You'd have to cut the zip tie. Not much fun on a hot engine .

That's why I would like to do it the way I did today. Do you know if the arm is suppose to be all the way up or is it ok if it drops down a bit like mine did?

I have been down on power as well but I was thinking it's exhaust related because I'm only seeing 18lbs boost at the most. I'm going to be home in a couple days and have 5 or so hours of driving to get there and was going to go through everything then but could that be fuel related to?

shootist · 09-06-2021, 10:24 AM

Quote:

Originally Posted by Craig1960

That's why I would like to do it the way I did today. Do you know if the arm is suppose to be all the way up or is it ok if it drops down a bit like mine did?

I have been down on power as well but I was thinking it's exhaust related because I'm only seeing 18lbs boost at the most. I'm going to be home in a couple days and have 5 or so hours of driving to get there and was going to go through everything then but could that be fuel related to?

Tie it up if you're down on power. Lack of fuel is really hard on your pump and they are expensive. If you don't see any difference with it tied up then I would not be so concerned.

Craig1960 · 09-06-2021, 10:50 AM

Quote:

Originally Posted by shootist

Tie it up if you're down on power. Lack of fuel is really hard on your pump and they are expensive. If you don't see any difference with it tied up then I would not be so concerned.

Good point, that's what I will do to see if it does make a difference.