Hesitating 2.25l diesel

[Hawaii_SIII]

I have a 2.25L diesel with 139k miles on the odometer. The motor will be puttering along at speed and then “stumble.” What I mean by stumble is that I’ll be putting along nicely then it feels like a strong gust of wind blows against or someone pulls the fuel cutout so it isn’t fully open. It isn’t misfiring, but rather just losing power and RPM. This phenomenon has been occurring for the last 5 months and has been getting progressively worse. At first the motor would stumble once in awhile uphill in 4th gear. It has gotten worse lately and now occurs in 2nd, 3rd, and 4th gears and is most pronounced while accelerating. I have been using Power Service Diesel Fuel Supplement since November to keep the fuel from gelling. The problem seems to occur more when the tank is less than half full. I think it could be the fuel filter (last changed 15k miles ago), fuel pump, or maybe the injectors. Has anyone experienced this or have any tips on narrowing down the problem?

[Tim Smith]

It sounds like air in the fuel line. Go ahead and replace them.

Diesels only need so much. Compression, injection and fuel.

[SafeAirOne]

I agree that it sounds like a fuel delivery issue. This happens to my 2.5 diesel when the fuel system can't supply enough fuel to meet requirements of the engine (more power to get up hills or drive on the highway). The problem has invariably been a clogged screen on the uplift tube inside the fuel tank. I'd check your entire fuel system including filter and screens.

[KevinNY]

Does the 2.25 diesel have a cable stop or solenoid to shut off fuel. I had the same problem and it turned out to be a broke wire to the stop solenoid, the insulation was still holding it together but occasionally it would cut out just as you described. If a solenoid is involved, inspect the wire and connections for it.

[SafeAirOne]

A 2.25 should have a cable stop. I sure wish my 2.5 had a cable stop!

[Les Parker]

It could also be the fuel lift pump nearing the end of its days.
A worn out diaphram can pull air into the fuel.
Is the glass bowl on the fuel pump full of fuel?

[Hawaii_SIII]

I think it's a clogged fuel filter. When I was driving to work this morning, it would bog down in all gears when greater than half throttle. It made for some fun before getting off the interstate. :mad: I checked the fuel cutoff cable and that is working fine. When I had the tank drained this fall, the pick up screen was clean and the inside of the tank didn't look like it had too many floaters or sinkers.

On the possible impending failure of the fuel pump; it won't hand pump via the lever as I found out last time I had to prime the injector pump. The fuel pump doesn't have a glass bowl either.

I'll replace the fuel filter tom, take a peek in the tank to look at the pick up screen and then check all the fuel line connections. If that doesn't fix it, the next step would be a new fuel pump.

[superstator]

On the possible impending failure of the fuel pump; it won't hand pump via the lever as I found out last time I had to prime the injector pump.

I thought my hand pump was broken too, last time I replaced my filters. Then I realized I was only moving the lever through its play, and if I really pushed hard it actually worked fine.

[ignotus]

The fuel pump. I had simular symptoms and just replaced mine. Small crack in the diaphram. From under the vehicle I could see fuel spitting out the breather hole on the bottom side of the diaphram housing. It can probably be repaired with a rebuild kit, not carried by our hosts, look around online. I think the only difference between the petrol and diesel is the diesel has a heavier spring under the diaphram.
I took apart my old one and a petrol one to compare them.
The rebuild kit nolonger comes with the seal under the diaphram blocking the oil from entry. Be creative, I fitted a 1" brake wheel cylinder seal(the one on the piston) by making a center hole and cutting down the lip. I heard of this trick from someone who did it as a roadside repair, lasted several thousand miles. This will be my spare.:thumb-up:

[Hawaii_SIII]

I replaced the fuel filter today. After looking at it and seeing the gunk filtered out, I am fairly certain it was the filter. I took it for a drive post replacement and it was purring like a kitten.:thumb-up: I also took a peek at the pick up screen and that was clear.

[SafeAirOne]

That filter has 15K miles on it? Time to either change gas stations or start replacing your fuel filters with BRAND NEW ones instead of gently used ones! :D

Glad to hear it was an easy fix!

EDIT: You don't by chance, use a boidiesel mixture do you? I hear biodiesel frees up a lot of gunk in the fuel system...

[Hawaii_SIII]

As a matter or fact, I was using some biodiesel while i was in Hawaii. That's what i figure all the gunk was from.

I've read all the oil and oil filter threads, but I wonder if there are any fuel filter threads. Both the old and new filters are napa brand.

[SafeAirOne]

I've read all the oil and oil filter threads, but I wonder if there are any fuel filter threads. Both the old and new filters are napa brand.

Well, I'd say the NAPA filter has done its job admirably and trapped so much junk that your engine was being starved of fuel. Much better than the other option. :thumb-up: