94 7.3L idi wmo help!

[mudslut350]

Okay so I have a 97 7.3 psd I just started wmo in no problems whatsoever. Now a buddy of mine has a 94 7.3 idi. First we topped off his rear tank which had 3/4 tank no2 so it was 5 gal wmo and about 10 gal no 2. Right off the bat would not start. Not even off the no 2 still in the lines and filter. Since then got it started finally just by jumping it and turning it several times till it fired off. This last time we put 5 gal wmo in then topped it off with no 2 andtruck now stalls at least once in a 15 mile drive. Worked once without fail now consistently stalls. I thought if anything my psd would have more problems lol. Btw it has plenty of power runs fine no problems at all when it is running. Any help on the issue would be great. Thank you all

 

[leftcoastjeff]

Doh

First off, how did you filter the WMO?

Any water in that oil? IIRC That will swell the paper in the filter and block it quick.

Maybe the oil went straight to the bottom of the tank and you got nothing but WMO to the fuel filter?

You jumped and it started, I'd start there, then check for fuel flow.

Too bad it sounds like an intermittent problem, can be difficult to track down

I blend in a can, then pour in the tank.

Good luck,

LCjeff

 

[Brad S.]

X2 on the filtering.
About 1 year ago I put some unfiltered oil in my rear tank, I think it was about a gallon.
The pail the wmo was in was open and had a very fine amount of wind blown silt.
I found that silt in my fuel filter about a day later.
Is there a fuel filter light on??? or flickering??
I would switch to the front tank after a filter check, maybe try to get that fuel out of the rear tank.

 

[mudslut350]

The oil is filtered to 2 mic and sealed the entire time in 55 gal drum and is the same oil I put in my 97 7.3. I understand it goes to the bottom of the tank mine does to my filter light comes on and smokes more but it clears up and never stalls out. I can put 10 gal wmo in one tank and top off with no2 and not have a problem. His on the other hand just wont have it. We add oil it wont start even with a hot engine. And itll drive fine down to road not sluggish or anything then suddenly stall out. Get it running again runs fine for a weekend then stall out twice in a 10 min drive.

 

[775NVEVOX]

Hello
its my truck that is having the issues. a little to add as of today. If and when the truck stalls it will be about 40-55 mph and only when on the throttle about 1/2-2/3 pedal. if i'm running just normal fuel i don't have any issues I know of. after the first five gallons of oil. I changed the glow plugs and filter. not that it matters but oil change and filter. the fuel light will come on just before the truck stalls. the truck has always been a little hard to start. if you need any more info happy to supply.

Thanks for the help and advice.

 

[Dsl_Dog_Treat]

If the filter light is coming on, then the lift pump isn't able to supply adequate fuel therefore triggering the vacuum switch on the filter head. Try mixing the fuel before dumping it in the tank. If filters are fresh, the lift pump may be getting weak.

 

[mudslut350]

He has one of those green inline pumps like from oriellys. It on the truck when he got it wonder if itd be worth it to switch back to mech pump. Also with the truck running I was not able to get any pressure from both valve stems on the filter head. Either way yea that makes sense now I was not sure what triggered the fuel filter light. The little pump definitely pushes fuel though its not inop but weak makes a lil more sense. Any ideas on a good one to put on it?

 

[Josh Carmack]

MOST DEFINITELY Switch back to the mechanical pump to run anything thicker than no2. The little silly centripetal pump from Oriellys' will not pump more viscus fluid. The little auxiliary pumps sold as replacement fuel pumps are not positive displacement pumps.A positive displacement pump will be needed to pump vicous fluids, and then, they are only good if the fluid viscosity cannot overcome the vacuum created by the pump. That will happen in colder weather, and I am already seeing it myself. Those little electric fuel pumps rely on centripetal force to move fluids. Once they are flooded with a viscus fuel they almost instantly lose prime of sorts, or turn too slow to move the fluid. They are also NOT positive displacement, which means while they may not loose prime, they cannot force a fluid out. The best analogy I can make is like this. Those little pumps are like a fan, if you turn a fan on and then place it against a wall it'll run and stir air up right around the blades, but it won't move air across the room. Then apply that to an air compressor. You can block the output (the tank) but it will still move air into the tank until the pressure reaches maximum. While air is compressible, it makes that analogy a bad fit, but I think it suffices to make my point. In the mechanical pump there are two chambers of which the volume is varied by the motion of the cam follower. Despite some peoples belief that the CAM is what forces the fuel to move, it's actually the opposite. the cam causes the pump to draw in fuel, and then the return spring is what forces the fuel along. That design allows the return spring to regulate the pressure output of the pump which is determined by by the strength of the spring.

 

[pwjackson]

X2 on the mechanical pump, I can had a new mechanical lift pump on my 6.9 and could run 100% wmo. The electric pumps do not like anything other than straight diesel.

 

[FarmerFrank]

How many miles are on your injection pump?? will it start once the engine cools down? just throwing that out there

 

[Josh Carmack]

Farmer Frank In my opinion his IP isn't the problem in this case. It has been observed in many cases to actually help the symptoms of a worn IP to run WMO in them. It decreases the high pressure plunger blow-by and allows the pump to build better pressure. Temps were below freezing last night and I was able to run 55mph on my 95% tank, but anything faster would cause the FF light to ignite, and the tell tell surging of air intrusion., thats with a strong mechanical lift pump as the spring has been changed by the P.O. because he wanted to run a 2mic filter. So he says, Its been so many years since I saw the innards of a mechanical pump lol. I do know that the return spring is what controls the fuel pressure, and that is the case not with just our fords, but any mechanical lift pump.

I know that centripetal pumps Will Not pump oil from my own experience. When I first got started in this WMO venture I had very little equipment to move, store, or process the used oil. I attempted to use a bilge pump from a boat to pump oil for me and it failed miserably, and that was in the 70's for temps. I could hear the pump running down inside the IBC tote, but it wasn't moving anything. Thought the pump had gone bad, dropped it in a bucket or water and it came rushing out at 500GPH, drop it back in the oil, and nothing. Oil is so viscous it never enters the impeller of the pump because the shear forces upon entering the impeller are too high for the viscosity. now mind you, the larger the capacity of a centripetal pump, the larger the impeller, and the lower the shear forces. Hence why you can move oil with a large gasoline powered centripetal pump, but not with a little 20GPH lift pump.

 

[FarmerFrank]

i agree completly, like putting straight 50 oil in a 351M to get oil pressure again, its thicker and takes up the worn out space where as thin diesel goes by. In my 88 the pump head was so worn out that even on my w85 it would not start hot. I was just layin it out for him to play it out.

As for pumps i prefer a gear pump and a pressure regulator. I normaly have great luck getting them to prime and they seem to pull fluid from a greater distance. I run a small gear pump simular to a furnace pump with internal bypass for my filtration rig and a small electric driven gear pump on my trucks. They make a little more noise but who can hear it over all that clatter anyway??

 

[Josh Carmack]

Now I hate to hijack the thread, I do hope the OP has gotten some useful information, but I am very interested in what, where, and how, on your gear pumps!

 

[FarmerFrank]

i too might as well appoligize for the hijack.

Welllll, i work for a multi-billion dollar company that throws away good parts that never make it to the dumpster..... They only made 7.3 billion the second quarter of the year, and things are "slow". anywho, they donated me a gear pump that is about the size of my fist that i hooked straight to a 1hp motor. it then goes to a fuel filter head for a QSK 50 Cummins (2250 hp) with three fleetguard FF5644 filters (4 microns), then to my centrifuge (about the same size as PA bio diesels 55gph) then to my holding barrel. the pump itself is small indeed but i've seen it burry a 200psi gauge before i had a regulator on the system and that was also the day i found out what my burst pressures on my filters were... the set up has been good to me so far. if i can figure out how to upload pictures ill start a new thread with the set up because this site was a huge help with it.

The trucks have a Mr. Gasket pump. http://www.summitracing.com/parts/mrg-95p/overview/ i can explain in more detail if you are interested

 

[idiabuse]

Yep I'm reading here and have had lots of miles on WMO, lately I started crashing my truck into people, 3 incidents this year already, my front bumper has pissed off many people since 1999, still looking good!
But the 2nd incident started some weird alien crap going on with my fuel delivery system.
I built my two tank system some years back and it has been excellent.
A tee at the bottom of my front tank which connects to the bottom of the rear tank
that gives me constant gravity fed fuel to my pump electric right under my butt.
Well lately the aliens are screwing me. fuel don't like to get pumped up front to the engine.

I have all my lines out today searching for the root cause and nothing has been found.
I poured 8 gallons into my front tank and while I was getting ready to head to work my truck
idling warming up I noticed pressure loss on my gauge, it normally at 6/7 psi full time.

Upon further inspection the entire front tank was empty and the rear tank full.
that has never happened before to me, So I am like ***!
I always end up with things that make no damned sense at all.

I will work more on it in the morning, had enough BS today already...