More engine problems (Documentation of testing fuel system, failure of Hyd Head)

[patracy]

Well, let me explain the chain of events.

A couple weeks ago, I went over to a friends shop to pick up waste oil. I ended up pushing the truck too hard on a low tank of fuel. And ran it dry as I pulled into his shop. I thought, no biggie, I'll just top it off now.

Well in doing so, my airtex lift pump died (no longer "vibrates" or pumps). I rigged up another spare pump (12v) enough to get me back home. The truck ran ok getting home, but it certainly wasn't right. I believe the hose I had kept collapsing at one fitting.

I tried to restart the truck, nada, not going to run.

So fast forward to now.

I dumped all the waste oil in the tank and have 18 gallons of diesel in the tank now. I replaced the long dead in tank pump as well. I've gone through the process of purging the fuel lines. Lift pump on, I can crack the primary, get fuel there. Lift pump on, I can get fuel to secondary bleed port.

Pulled the HH center plug and turned on the pump, fuel there as well.

Bled the injector lines. Gave it a huff of starting fluid, was able to get it to run. Thought, wonderful, I'll let this thing run for a few minutes while I run to the bathroom. A few seconds after I walked into the house I heard the engine stop.

So I go back out there and find that the lift pump fuse had worked its way loose and fell out. (Found this out after cracking the bleeder lines and seeing no fuel coming out)

So I went through the purging process again. With several sprays of starting fluid, finally was able to get it running again. But it would only run at WOT, EGTs extremely high. It was smoking. I would slowly let off the the throttle, it would start to idle down, then a puff of white smoke and it would shut off. No starting again without starting fluid and WOT treatment.

So I thought possibly I had a sticking injector. I swapped all the injectors with the spare ones I had. Same results.

It's almost like it's out of time now, I know when I did the engine swap last summer, I timed it 180* out and it would start just like this and only run with WOT.

I'm going to check the engine timing tomorrow I guess. I know it can't be 180* out. But perhaps it slipped timing from the cog.

I'm just puzzled since it drove itself home. I know the 100% waste oil wasn't a good idea though.

 

[JasonS]

I know the 100% waste oil wasn't a good idea though.

IMO, burning junk fuel is like diggin' through the dumpster for a half-eaten, day-old donut.

 

[patracy]

Thanks, your disapproval has been noted.

 

[Heath_h49008]

Do you have a spare set of filters?

 

[welldigger]

This is just a theory of mine but maybe when you ran the lines dry some crud that was caked on the walls of a line or pump housing, etc, broke loose and is hung up somewhere in the IP causing something to stick? Air can cause crap to break loose when normally it would stay in place. Just a theory of mine.

 

[rrrr]

Well I had a similar problem when I found out that empty on my fuel gauge was at 1/4 tank !

I was able to reprime mine like you and make it to a station to fill up with diesel. I only run diesel in mine. I put in 25 gallons and a quart of Dex3 tranny fluid to help clean things up. The truck was weak running after that. I had about 100 miles to get home. Finally after an hour of running the truck at 55 (I have 395's on) it started to run strong again. I think there was some air trapped and it took that much running to finally get it all out. I also always use a diesel treatment it help keep the fuel and stop it from gelling.

You might need to replace all your fliters as well. Is the fuel shutoff working and not partially closed ?

 

[gimpyrobb]

I really doubt you jumped a tooth, maybe quill shaft issues. I have heard of them breaking. I agree with starting at the filters and going from there.

 

[patracy]

Fuel shut off it moving freely, forgot to mention I checked that.

If it was a quill shaft, it wouldn't run at all.

 

[phil2968]

Re: More engine problems (fuel system)

I would bet the HH plunger is not stroking like it should. I ran my truck back home for 500 miles after the 12SSGR without a working lift pump. If the system is primed the booster pump will keep it going.
A spare HH would be nice in a situation like this.

 

[gringeltaube]

Phil, yes, could be the plunger sticking, but if it moves up-down 5.5mm, consistently, while turning engine over, that could be excluded IMHO.

From the description it also sounds like timing was way off but.... if nothing was disassembled it only could occur (to some degrees, retarded) if.... the 3 bolts securing the IP-driven gear to the IP hub had worked loose somehow... not very likely.

Drew, you didn't mention having checked the fuel pressure, on top of the 2nd filter...? It really is such a simple & quick test to make sure everything between tank and HH is working like it should.
Remember: 5-7 lbs from lift pump, engine not running; 35 lbs @ 800 rpm, no load; 60-65 lbs @ 2600, no load.


G.

 

[mcmullag]

I believe I had a similar problem where if engine would start at all, it would go to WOT.
The fix: two diesel mechanics separately advised me of this. Diesel fuel and atf, with 1/4 of the mix being automatic transmission fluid. Cleaned tank, changed filters, ran fuel pump with this mix for couple hours to get the mix thru the system.
I then ran engine on that, truck just sitting there, and it started slowing down and cured itself.
Original problem: I picked up the truck from GL at Ft Carson. A 1987 air force reserve unit had it at Peterson afb here,and only 13000 miles on it,
just not used, just sat. Found out after I drove it home, about 10 miles (ran normal for the drive home) the fuel tank had at least an inch of brown goo in
the bottom, the two secondary fuel filters were just full of brown goo. Runs great now, I always use diesel fuel from the store.

 

[Stretch44875]

I've had a problem with 100 percent oil, in the winter. Right now the M108 won't run, keeps getting air in the fuel system. Oil is just too thick for the lift and booster pump to get it going, think the booster pump is sucking a vacuum in the lines, and getting air in.

Plan to change all the filters, thin the fuel, replace starter, and hope it runs.

 

[patracy]

Yup, going to change the filters (even though I get flow with the LP running). Fuel is now 18 gallons of diesel. Course it's still black from the WMO residue.

 

[wreckerman893]

Well I had a similar problem when I found out that empty on my fuel gauge was at 1/4 tank !

The only thing that lies more consistantly than a career politician is a MV fuel guage.

 

[patracy]

Ugh, this is fun!

Primary filter looked ok, replaced anyway. Secondaries were totally my fault. I bought the engine used that's in the truck now. I had swapped the filters on my first engine. When I swapped engines, I forgot to change the filter housings. So the secondary filters were pretty nasty. The first primary filter had gunk caked over it.

Hooked up a oil pressure gauge on the purge port. Had 5-7psi from the lift pump to there with master power on. Didn't have any increase in pressure while cranking. Had my son hit the starter while I wiffed it with starting fluid. Eventually it started running. Got it idling great and revving. With the engine idling I saw about 35psi. So I revved it to high idle and saw 65-70psi. It then stumbled and shut down. Not restarting now. Still have 5-7psi with the master switch on. But it doesn't build pressure when starting (actually starts dropping).

I'm going to get my son to help again. I'm going to pull the center plug and verify the plunger is working correctly. If that works correctly, the only other thing I can think of is the check valve on the booster pump. (Or a bad HH now?)

 

[Heath_h49008]

I would be somewhat surprised if one load of bad fuel would take out the HH that fast. Did you check the screen on the lift pump?

 

[rrrr]

I think you might have air in the system. Try purging the fuel lines again to make sure fuel is getting through. Some bad stuff might have gotten through the filters into the HH and is causing the issue also. Is the fuel shutoff working correctly and not closing on you ?

 

[gimpyrobb]

Nah, if he gets 5-7psi, its not dirty screens. I wonder if the by-pass valve has gone bad. The T fitting right at the front of the secondary filters.

 

[Heath_h49008]

You think some crud might have just lodged in the port?

 

[doghead]

The HH could have been ruined from starvation.