Engine/Transmission (1994 - 1998) No fuel from inj pump

[DDennett]

Well I had the injectors tested all of them were 400 psi low and 1 had excessive leak down so I had them rebuilt. I got them installed and now I can not get the truck to start. I have fuel into the injection pump but no fuel out. I have tried bleeding this thing every way imaginable all to no avail, its to the point were the batteries are weakening. Everything on the fuel supply side has been replaced already, fuel lines, overflow valve, lift pump, all seals and grommets, fuel filter and pre filter are new as well. What gives? How long does it usually take to bleed the high pressure lines? I cranked it with the fuel line coming out of the delivery valve loose and nothing. It was running before I replaced these injectors so I don't see how the pump could just all of sudden fail while I am trying to get it started. Do I just need to be more patient and keep on cranking or am I looking at a catastrophic failure of the injection pump? Any suggestions are appreciated.

thanks

Demian

 

[CToney]

I had the same trouble after changing my headgasket but the lift pump was nfg. Keep all the injection lines tight on the pump and have the rear three injector lines on the injectors just finger tight and the front three quite loose. crank the engine for 30 secs let cool for 2min and try again until you see fuel spraying out of fittings then tighten the fittings and she should start. Try the prime button a few times you should hear fuel going over the overflow. If you don't you have a lift pump or overflow problem.



Good luck



CR Toney

 

[Vaughn MacKenzie]

Demian, make sure the shutdown solenoid is energizing and pulling up to the Run position. Take a look at this diagram here and find the part on your engine that is labeled "Fuel shutdown solenoid" http://dodgeram.org/tech/dsl/Facts/figures/12Ve_locations-l.gif



Once you find it, feel below where the rubber boot is. With your ignition key "on" try pulling up on the lever the rod connects to. If you're able to pull it up and it clicks into place, that was your problem. When it's in the Up position the fuel valve to your pump has been opened, and it should start after a little cranking. When the solenoid gets weak and/or your battery gets weak, it doesn't pull itself up to the run position, and therefore fuel to your pump is cut off.



Remember when you go through your cranking cycles, don't turn the key all the way off, otherwise you'll have to go back under the hood and pull up on it again.



Once you get it running and your battery charges up, the problem should go away. Good luck, let us know if that was it.



Vaughn

 

[DDennett]

The shutdown solenoid seems to be working as advertised and correctly adjusted, it pulls up with the key in the crank position and stays up until the key is turned off. I can here the overflow valve sing while priming and I am getting fuel out of the bleed screw on top of the filter. I'm about at my wits end with this thing, at what point do I give up and pull the injection pump to have it checked out? At which point they will probably tell me there is nothing wrong with the pump and I will go completely insane! Anyway I appreciate the help and of course any further assistance will be greatly appreciated.

thanks

Demian



One other thing I just thought of, when I took the high pressure lines off to replace the injectors 2 of the delivery valve sockets/holders were loose, not falling off loose, but no where near 85 ft lbs, is this a sign of some other problem or just a case of 2 loose fasteners?

 

[TGroves]

this may be left field but here goes ,,, my truck would stay running and it came out to be that the key that keeps the truck running and shuts it off ... ,,, broke ,,, little lever just below the solenoid,,, held by a 8mm bolt ,,you will have to pull that off to look and see

 

[jeepullr]

I'm about at my wits end with this thing, at what point do I give up and pull the injection pump to have it checked out? At which point they will probably tell me there is nothing wrong with the pump and I will go completely insane!

Hold off as long as you can for having the pump tested... Mine was $400 to have tested... only to find out that the plungers were bad... rebuild was gonna start at $3000 and go up from there.



If you know that the injectors were your issue, then nothing should have changed with your pump.



When I replaced my IP, this was my restart\bleed proccedure:



Loosen banjo bolt at IP (line coming from fuel filter),

Hand pump till I had flow there,

tighten banjo bolt and hand pump till the IP screamed

Loosen all six fuel lines at Injectors (have them tight at the IP)

Crank motor till I had good flow at all injectors,

tighten fuel line fittings

Crank motor again...



Fortunately mine fired at this point. I had leaks at the hold down bolts on 2, 5 and 6. And leaks at the fuel line fittings on 2, 4 and 6.



It is a major PITA to get these things right... and any air in the lines just pressurizes and doesnt move.



Good luck.

 

[Howard Durand]

This may be a dumb question but is the pump actually turning when the engine is being cranked?

Did you have the linkage apart when you were working with the fuel shutdown solenoid?

As mentioned by TGrove, there is a little half moon key in the shaft that operates the fuel valve and is real easy to lose. I can't see how it would be broken but if it is or is missing there will be no fuel to the pump.

 

[DDennett]

Well the pumps out now, so we shall see what comes of it. The woodruff key for the shutdown is there and intact and the shaft turns stop to stop. As far as wether or not the pump is turning I can only assume that it was, the gear is intact and the engine turns over just fine. I have cranked the **** out this thing and there is just no way that it can take this long to bleed the high pressure lines, there had to have been fuel in the pump after reinstallation of the injectors because other than the high pressure lines I had nothing disconnected at the IP. I get good fuel flow out of the bleed screw on top of the filter and there is fuel to the inlet side of the pump. You can here the fuel bypassing the overflow valve while priming. The only component that doesn't seem to be doing its job is the IP, I don't get it either since all I changed were the injectors but I don't know what else to do short of having it towed to diesel shop where they are probably going to do all the same things I have done and end up at the same place only for a lot more money. I am an aircraft mechanic by trade so I know which end of a screwdriver to hold and I have tried to go about this logically, which the logical next step was to pull the pump, so here I am. I will update when I know something more. Thanks for all the help fellas!

 

[Howard Durand]

When you pulled the pump, was the nut tight that holds the gear to the pump shaft? They have been known to slip in the later models. I wouldn't think that it would loosen enough to keep the pump from turning but possibly enough to really mess up the timing.

Hard to imagine the IP becoming a "black hole".

 

[DDennett]

Yeah the nut was tight and so was the gear, it gave a nice "pop" when it came loose from the shaft. I am half tempted to put everything back together and try it one more time but I just don't know. Oh well tomorrow is another day.

 

[Vaughn MacKenzie]

Sounds like you covered your bases well and taking the pump out was the only option you had left.



I have R&R'd two P7100 pumps and never had much trouble firing up afterwards. All I did was push the primer button until I could hear the OF valve squeak, then cranked it. Never took more than 2-3 rounds of cranking for it to fire up.



Vaughn

 

[Howard Durand]

Maybe connect a gauge to the fuel line that was removed from the pump and see what is going on with the fuel delivery.

 

[DDennett]

Sounds like you covered your bases well and taking the pump out was the only option you had left.

Thanks Vaughn, the pump is at the shop now, so I should know something this afternoon.



Thanks to everyone for the help, it was all good information.

Demian

 

[Vaughn MacKenzie]

Any updates?

 

[DDennett]

Yeah I talked to the pump shop today. The good news is I am not crazy, the bad news is the pump is going to cost $2300 to fix. The 4&5 delivery valves somehow got shoved down inside the pump or something to that effect and wreaked all sorts of havoc. He told me exactly what happened but when I was talking with the guy I was at work and had a plane gate return on me, so I was a little preoccupied. I asked if he had any idea what caused it but he really didn't know. I wonder if I screwed them up when I tightened the holders, or if the holders were loose because something was already screwed up and I just excacerbated the problem by retightening the holders. Hind sight I should have taken those 2 dv holders off and had a look see if anything was out of the ordinary, but I just figured they came loose with the lines. Oh well, I should have the pump back on Friday and the truck back together on Saturday. Once again I really appreciate all the help you guys have given me, it definitely makes the membership worth it!

 

[Howard Durand]

Bummer! Could it be that the only thing holding those DV's in place when it was running OK was internal pump pressure?

 

[DDennett]

I don't know enough about the internal workings of the pump to make an educated reply... good question... I will quiz the guy at the pump shop on Friday when I pick up the pump.

 

[Vaughn MacKenzie]

Huh, that's kinda bizarre



Well hopefully the $2300 includes some calibration/tuneup tweaking.

 

[DDennett]

Got the pump in last night but had to finish up this morning due to rain. She roared to life on the second start attempt Oo. The truck runs better than it ever has, so I must say, despite having to shell out all that cash, I am pretty happy now.

The pump guy showed me the old dv plunger, it was split right in half. He said they have seen this a couple of times but not very often. Probably caused by some sort of hydraulic lock condition, whatever it was it certainly wreaked some havoc on the pump internals. So I wound up with a new housing, 2 dv assys, and whatever else is involved in a pump rebuild including calibration and they even painted it.

Once more I would like to thank everyone on the TDR that tried to help out.

Demian