Looks like I may need an injection pump

[ChrisWilliams]

Well, the lift pump went out on my 91. 5 and it may have got the VE as well. My dad and uncle were towing a load back to NC from VA and it just shut-off about 100 miles out. They told me it got a little sluggish going up hills on the way back. Checked the shutoff solonoid, also the filter was dry and the lift pump offered no resistance when pumping manually, so had the lift pump replaced and bleed to the injection pump. It still wont hit a lick. When the weather warms up, dad is going to crack #1 injector line and see if fuel spays everywhere. I'm hopeful, but expecting the VE will need replacing. The truck had plenty of power with the stock pump, for what we do with it, so I would like to keep the pump stock is possible.



So my questions are: Is a rebuilt VE the only "stock" replacement option? Any recommendations on where to get a good reasonably priced pump? Given the new ULSD fuel, are there any pump upgrade options I should consider?



I'll go ahead and say, yes, I learned my lesson, the fuel pressure gauge is on order.

 

[JLEONARD]

Normally a lift pump failure doesn't take out a VE pump.

You probably just need to open up a couple of lines at the injectors and bleed the system out a little better to get fuel thru the VE.

 

[dpuckett]

Get a 17mm wrench, crack the injector lines, and see if it bleeds out.



If it's cold unhook the grid heater relays.



Fuel should squirt on the underside of the hood if all is well.



Major upgrades are a 366 governor spring, steel throttle shaft bushing. Get a new set of springs, and a new advance piston upon rebuild.



Daniel

 

[Forrest Nearing]

do first gens have smaller injection line nuts?



I seriously doubt there's anything wrong w/ your injection pump

 

[Greenleaf]

Yeah, I find all the P-Pump engines on the buses are 19 mil and the lines on my trucks are 17 mil.



The VP-44 units are 19 too... ... ... ... ...



I too seriously doubt there is a problem. Some guys sell rigs like this and the new owner only has to install a new battery and bleed the injection pump/lines.

 

[ChrisWilliams]

Thanks guys, I'll let you know how it turns out.

 

[JLEONARD]

install a new battery and bleed the injection

Good point Scott. .

she no spin fast, she no start

 

[ChrisWilliams]

It ain't over yet. Looks like I will have to go up to NC and work on the truck myself. My dad had a local mechanic, who towed the truck in, to replace the lift pump and bleed to the VE, but the truck still would not start. I knew something wasn't right and after hearing from you guys, I talked with dad and explained how to bleed the system, starting at the filter bleeder, then the feed line at the VE, turn on the switch and manually pump the lift pump to fill the VE, and finally crack a few injectors... He and the mechanic tried to bleed the system. He gets about two pumps of fuel, then starts getting air with a little fuel. They pump and pump, but never get only fuel. At this point, instead of stopping and working backwards to the tank to find the problem, they keep going. Now, they have opened the fuel system from the filter to the injectors and, of course, haven't gotten anywhere. They even filled the tank with fuel and tried to bleed it off again. You must have good fuel flow to the filter before you can go further. I'm thinking there is a cracked and/or collapsing line between the lift pump and the sump in the tank. It has the 5/16 metal lines along the frame rail, but there could still be a problem there. My plan is to replace the lines from inside the tank to the lift pump. I am thinking of using some 1/2" J30R7 fuel line, a 12 micron fuel water separator under the bed and a Vulcan Draw Straw in the tank. I have been looking at the Vulcan Draw Straw to replace the sump. It is listed as a Gen2 part on Vulcan's website. Will this work as a direct replacement to the stock sump and return or will I need to plug the original lines and drill another hole for the Draw Straw? I'll call Vulcan after while, but I wanted to hear if any of you guys had used one on your rig.



I also found out a little more about what happened before the engine shut down. On the trip to VA, they noticed the truck didn't have as much power as it usually does, but was running fine. When they loaded and started back from VA, the engine would hesitate and stumble at WOT on long hills. They drove like this for 200 miles before the engine shutdown on the back side of a long hill. They were towing my 16ft dump trailer, about 4,500# on the way up, and loaded, about 10,500# on the way back. I'm hoping they didn't toast the VE. I know the VE is tough, but 200 miles starving for fuel and ULSD at that!

 

[Greenleaf]

If the lift pump was on a high spot at the cam it will do nothing. It could have been good but I have no idea how long it was on there and the pressure.



Always run with a lift pump pressure gauge. It will tell you worlds of knowledge. I recommend the Westach for trouble free performance and ease of install.



Did you pull the shut off solenoid? Look careful at the plunger tip for metal sparkles. It tells you what is going on inside. Did anyone check for 12+ volt at the solenoid? Did anyone pull the rubber plunger out and install the body to see if it will fire. Also, pull that thing out and pump the lift pump (with the cam on a LOW spot!!) It will run fuel out.



You have work to do... ... ... ... ... ... Lemme know.

 

[JLEONARD]

do first gens have smaller injection line nuts

Forrest... our nuts may appear smaller but it only an illusion. :-laf:-laf

 

[ChrisWilliams]

The story continues... Dad finally got the system bleed off good. There must be some problem between the lift pump and the tank, because he had to run the lift pump from a 5 gal. can to get good fuel flow. Anyway, he ran the return line into a separate can to verify he was getting good fuel flow through the IP and also removed the solenoid plunger and lost it. #@$%! Blew a chunk out of the top of the battery grinding the bracket on the IP , another story for another time.



He bleed it off at the filter and the IP, Cracked #1 injector, cranked a few seconds, waited, pumped manually, cranked more, did this several times. All total, ran about 2 gallons out the return line and got nothing at the injector. I ordered a reman IP this afternoon and will be heading up to NC next week to install the IP, a new fuel pressure gauge, and replace the fuel lines from the lift pump into the tank. Thanks for all the good info, I'll post when I get the rig running again.

 

[ChrisWilliams]

I got her up and running this afternoon. Oh she sounds good singing that sweet sweet song, rattle rattle rattle rattle. I wound up replacing the fuel system up through the lift pump and replaced the injection pump. I staked the KDP while I was at it too. I have a little wiring left to do tomorrow for the fuel gauge, but the hard work in done. I'm not sure what the original problem was, but those rubber lines at the tank were really soft. I was very surprised at the size of the original pickup line in the tank, looked like 1/4". I also found some fuel on the metal lines under the cab. Anyway, what ever the problem was, it got the VE.



I put a new draw straw with return in the tank, plumbed in a filter/water separator under the cab and tied into the lift pump with 1/2", then ran 3/8" from the return tee at the back of the motor to the tank. Those lines are a little big for a stock setup, especially since a 12mm fitting only has a 3/8 hole in the center. If I knew what I know now, I would have replaced the return with 1/4" and the feed line with 3/8". Anyway, I have room to grow later. Next is a piston lift pump and 3/8" lines to the VE, but not right now.



Thanks for all the info and advise, it would have been a whole lot harder without you guys.

 

[DThibault]

Chris, I have to replace the lines in my 91 someday soon but I will wait till spring and take the bed off so my body doesn't have to go through contortions. Did you do the whole thing with rubber lines? I was going to try to find the original plastic ones. Thanks for the help.

 

[Greenleaf]

Wow. You really needed an injection pump!! Man. I wouldn't have guessed that. Happy to hear it's ok now.



School buses;



They use Parker Par-Flex HTFL8



(high temp fuel line) Looks like plastic air brake lines. They use the same brass ends. They have an insert/nut/ferrle and the fitting of your choice. I know the talk is stainless steel braided hose but... ... man. Isn't that a little corny? I mean if you have a glossy hose fetish, then yeah.



The Parker fuel hose (plastic tubing) is bought is a large roll and you simply cut it and install the ends. I know... ..... that's too easy and it aint stainless... . Whatever. :-laf The plastic is approved by the ohio state school bus construction standards which is the most ridged set of laws on the face of this Earth. Trust me when I tell you.



Oh... ... ..... the size. Brace yourself if you have one of them "big shinny fuel line fetishes" . The buses are 1/2 " RETURN and 3/4" SUPPLY. I know. some of you guys feel sick, but it's true. Your going to have to go bigger now.

 

[ChrisWilliams]

Pulling the bed is definitely the easiest way, especially if you have a motor hoist around. I had the bed off in a half hour and back on in a couple of hours.



I called up Eric at Vulcan and sourced all the lines and fittings through them. I got the parker marine grade rubber line with push-lock fittings. That is some nice tough hose, takes a sharp knife. You need to warm the hose a little at the ends and make sure you eat your Cheerios before trying to push the fittings in. Braided stainless steel is nice but it is a PITA to cut and fix the ends. Besides, I was concerned it might collapse inside.



There were three places where it might rub a hole, one where it runs from the bed to the cab (10" piece of radiator hose covered both lines nicely), one where the hose comes out of the filter mount under the cab (short piece of 2" rubber hose over the feed line) and another near the transmission linkage at the firewall (about 14" of 2" rubber hose). It'll never give any trouble now.