Injection Pump???

[mdelay]

99 F250 superduty 7.3L turbo.

We had a bad freeze last year (-36) and the diesel gelled. It started not running right, loss of power at random times eventually dying. We replaced the fuel pump, fuel filter and it was running good for a few months. Now it has started running bad again. Replaced another fuel pump and filter (thought maybe there was still some residual gelling) but no go. Ran some diesel kleen through it, a little better.

It is running good at speeds less than 45 mph all day long. After about 5-7 minutes of 45+mph it looses power until it eventually dies. Someone suggested the CPS that was recalled. It was replaced after the recall, but just to be sure we replaced it again. Still nothing. Took it to a diesel mechanic who ran a compression test which showed #8 injector failure. But was told it would not cause it to run like it does. Thinking the injection pump......but don't really want to spend the money on it if thats not it. Don't know too much about diesels as this was my dads and its our first one.

 

[DaveBen]

This, and all Super Duty Diesel trucks are computer controlled. There probably are codes stores in the PCM (Program Control Module) that you will need to get retrieved. You can do this with a Scanner like AutoEnginuity® - OBD2 Scan Tool - Professional PC and PDA Diagnostics or some sort like it. A good mechanic will have a good scanner to get these codes. Have it scanned to see what is going on. We are guessing without a scan.

Dave

 

[mdelay]

Sorry, forgot that part....No codes came up when scanned

 

[BIG JOE]

99 F250 superduty 7.3L turbo.

We had a bad freeze last year (-36) and the diesel gelled. It started not running right, loss of power at random times eventually dying. We replaced the fuel pump, fuel filter and it was running good for a few months. Now it has started running bad again. Replaced another fuel pump and filter (thought maybe there was still some residual gelling) but no go. Ran some diesel kleen through it, a little better.

It is running good at speeds less than 45 mph all day long. After about 5-7 minutes of 45+mph it looses power until it eventually dies.

When #2 Diesel (any fuel) Gels, allot of sediments that would normally be trapped by the filter.. go into suspension, (in the gel mass) when the fuel warms... the sediments fall out.. and go the the bottom of the fuel tank and form.. Muck/Mud.

In the bottom of the tank, on the bottom of the fuel pick-up tube, there's a Screen. Kinda sounds to me.. that screen is, or gets, plugged.. cutting off your fuel supply.

If, over time (1999) & miles, along with the gelling.. you may have enough Muck built up.. that during idle and low speeds, or for awhile.. it'll run. but when you put any fuel demands on... the screen plugs up.. and it Dies.

It's not that hard to drop the tank. Triple rinse it with Soap & water. Dry it Good. Clean the screen.. Re-install everything.. fill it up. re-prime the fuel system.. Start it & Run it.. in a coupla days.. change the filter.

Yul be good to go

I'm think'n.... thats yer Gremlin.

 

[DaveBen]

I think Joe has hit a home run!

Dave

 

[dpantazis]

the 7.3 you have does not have an injection pump, it has unit injectors. a low pressure lift pump feeds fuel supply to the injectors, but the high pressure oil pushes a piston inside the injector to mist the fuel.
the non-powerstroke 7.3's have traditional injection pumps, like the 6.9's and the non-turbo 7.3's.

that said, try what joe suggested.

if you look at the wiki for the hutch mod, you can see parts and pieces of what you are looking at.

also, air in fuel can do that too, the fuel pump fittings are notorious for sucking air. make those good too.

 

[BIG JOE]

the 7.3 you have does not have an injection pump, it has unit injectors. a low pressure lift pump feeds fuel supply to the injectors, but the high pressure oil pushes a piston inside the injector to mist the fuel.
the non-powerstroke 7.3's have traditional injection pumps, like the 6.9's and the non-turbo 7.3's.

that said, try what joe suggested.

if you look at the wiki for the hutch mod, you can see parts and pieces of what you are looking at.

also, air in fuel can do that too, the fuel pump fittings are notorious for sucking air. make those good too.

X2 mdelay. Air Could, probably Would, be getting in to the fuel too.. on acount of the fittings dp talks about... due to the plugged screen.

(the fuel pump is trying to pump fuel. It can't, because of the screen.. so it sucks Air in.. thru some faulty fittings. engine looses fuel prime.. dies)

If yer guna drop the tank ? NOW, would be a good time to upgrade the Fuel Pick up assembly.... by doing the Hutch Mod, the Harpoon Mod, and the Fuel Pump Inlet delete Mod.

Use our Search feature, read up on'm.. if you have ANY questions ? Post'm Up.

Seeeee.... in just two Posts.. you've been Dezelmacated..

Joe

 

[mdelay]

Great! Definately makes sense. Will try that....Got jeep troubles too....lol

 

[DaveBen]

Sorry, but we don't do Jeeps, even though several here have them. There is a Jeep forum at JeepForum.com - Jeep & Off-Road Discussion Community.

Dave

 

[mdelay]

have tried many jeep forums, can't figure it out....thanks for the link though, but unfortunately that one has been tried too.... Hopefully the truck will be good to go, and can haul it in to a mechanic....