Installed my rebuilt 250 Cummins fuel pump

[70deuce]

Took my Cummins 250 fuel pump off to let the people at Marini's Diesel in Commerce City, CO do their magic on it. They specialize in Cummins motors. My M818 was getting harder and harder to start and had an messed up idle. Also after idling for a few minutes you could floor the pedal and nothing would happen for a few seconds. Anyways they went completely throught the pump. Mainshaft was worn, most O-rings and springs were shot. They bumped up the output by about 15%. Man does that thing run now. Way crisp throttle response. Finally have some dark smoke coming out under load. Starts right away, idles way smooth. These guys had already done the injectors so now I have a better than new fuel delivery system on this truck. One thing all 250 owners might want to check is the rubber coupler that goes between the three accessory drive teeth and the pumps three teeth. Mine was completely GONE!!! See pics on what it should like. After 37 years it came apart at some point and disappeared into to the oil pan. The pump was driven through metal to metal contact with an inch and half worth of slop. The Marini guys say this is not uncommon even on newer engines. Pump comes off fairly easy an is not timed. Rebuilt pump came back with a new one and flange gasket.

 

[papercu]

Great fix and pictures. Would the price scare us? Wayne

 

[area52]

If you don't mind, how much did it cost for the work?

Looking sharp and glad to hear its running better!!

 

[area52]

Was that return spring on the emergency shut off valve a "field mod" by you?

 

[70deuce]

Might not. They charge $425 to do the work on this pump no matter if they have to replace everything or just do adjustments. For how this runs now it might be on the higher side but it was worth it.

 

[70deuce]

Yes it was. I put it on there to ensure the valve stayed all the open and would return to open if I ever had to pull the t-handle.

 

[area52]

How long did they take to do it?

 

[70deuce]

should have come out "all the way open" in my previous response.

 

[70deuce]

Two days. That shop has one guy that just does injectors and pumps.

 

[papercu]

My switch shut down has never worked but I found another one of those stops that is on the end of the wire and put it ahead of the shutdown lever. Now it works like the deuce. Wayne

 

[70deuce]

Wayne you probably already checked this but is your knurled knob shaft on your shutoff valve turned all the way out? If its turned in the electric shutoff will not work.

 

[papercu]

Never looked, when I first got it I didn't know any better and I'm used to it now. Thanks for the price, doesn't sound bad. Wayne

 

[jwaller]

makes me want to pull mine to check the rubber washer.

 

[70deuce]

Except for the lower block side mounting bolt and maybe a new gasket, it doesn't take much more than 45 minutes to have that pump off, check for that rubber snubber and have it back on. That lower block side bolt is a bear to get started once its out.

 

[gem1410]

Did your engine ever have a slow return to idle after acceleration before the pump was done?

 

[70deuce]

Sure did. Its definitely way better in that regard but while putting the pump back on, I found a small crack in the large feed rubber fuel line right at the fuel pump input fitting. This was a small leak I'm sure added to th slow return to idle. Since they are rubber lines over barbed fittings I just cut the last inch off the fuel line off the fitting right at the fitting, slipped the remaining hose over the barb and put a hose clamp on it. Did this on the smaller rubber return line that goes from the pump to the hard line on the frame but replaced the whole length of line with new line. I am going to do the same with the feed line replacing it from the filter to the pump. No telling when the remaining line will develop another leak. Need to do all the tank lines too I'm sure. But I can tell you this, the rebuilt pump really makes that motor "crack" off a very smooth idle with just a touch of the pedal. Man its responsive now.

 

[area52]

70deuce - thanks for the info, something I am considering for my M816.

 

[vinny-socom1]

Thanks for the info!!!

Vinny

 

[hoopsoft]

Wow I bet I'm thinking like most of these guys, it would almost be worth the $400 just to get the extra HP from the increase shaft size. I wonder how much it increased your output.

 

[70deuce]

Going by what the experts at Marini say, a healthy 250 at 5500' is probably putting out only around 140 HP still with gobs of torque. They bunmped out the output of the pump 15% so maybe I have 160 hp now. Pullled the 38 foot van trailer for a test and hills and even a sweet running 250 still kill ya. Without the trailer the off the line performance is impressive now. The starting and idle performance are drastically better also. This AM at 42 degrees using the cold start procedures (glowplug for 30 secs) it started right up after about 3 compression strokes.