IP troubles...

[BlazeKeeper]

Hey all,

I recently bought an 89 F250 7.3 idi non turbo 5 speed. I got it for a great price, because it had "fuel issues." The guy bypassed the lift pump and fuel filter with an electric pump with inline filter just to isolate his fuel source, and put a reman IP on it from Pensacola Diesel (shudder) but it still isn't getting fuel to the injectors. I figured he didn't purge the air out of the lines, so that's where I started. Charged the batteries all the way up, cracked the injector lines, and cranked on it.... for about 6 hours. I'm barely getting any fuel to the injectors. I ran a hot wire from the battery to the FSS (even though I'm getting good voltage from the stock harness) just to make sure, and I hear it clicking. I'm getting a small amount of diesel from the return line on the top of the pump, but basically no fuel through the pump to the injectors. Before I pay $700 for a new IP, I want to replace the FSS to make sure that isn't my problem. Does this sound like a good place to start? I'm not new to mechanic work, but this is my first diesel.

Any help you guys can give would be great!

Thanks!

 

[DrCharles]

If you have fuel to the IP, and the FSS is clicking, and there is no fuel to the injectors, then the problem has to be in the IP!

 

[Thewespaul]

Try cranking the engine over with the glowplugs out, see if you get fuel at the injectors then.

 

[BlazeKeeper]

I've already taken the pump off, because I was going to take it to the local diesel shop and have them test it. Until I found out that they're going to charge me 150 just to test it. I can theoretically throw it back on one afternoon this coming week and try that.

Forgive my ignorance, but what does taking the glow plugs out do?

Not really relevant, but I did test the glow plug controller and it's working, and I bench tested all the glow plugs and they all work. So there's a couple things I won't have to replace right off the bat lol

 

[Thewespaul]

It’s like taking the spark plugs out of a gasser. So the engine has little resistance to spinning so you have a better chance of building pressure in the ip and displacing fuel.

 

[BlazeKeeper]

Makes sense. I'll give it a shot. I'm just trying to exhaust all other possibilities before spending so much on a new pump.

 

[IDIBRONCO]

Nothing wrong with that. Just make sure that you buy from one of "The Big Three" in order to get good quality. They are R&D IDI Performance, Conestoga Diesel, and Russ (member Typ4 on here).

 

[genscripter]

Just to make sure, are you cracking your injector lines at the injectors? I'm sure you are, but I have to ask. If not, read this.

Whenever I run my IP dry, my internal metering valve seizes shut. No fuel will get pushed out of the IP to the injectors. The only solution that I've found is to open the top of the IP (careful to remember how to reinstall it just as you found it) and wearing a brand new latex glove, I wiggle the metering valve to get it from unsticking. I've only had to do it three times in the history of my IP, but every time resolves my no-diesel issue. (Note, if you are a diesel noob, I don't recommend you opening up your IP. Take it to a shop and spend the $150. But if you are pretty technically or mechanically savvy, you could give it a shot.)

 

[BlazeKeeper]

Just to make sure, are you cracking your injector lines at the injectors? I'm sure you are, but I have to ask. If not, read this.

Whenever I run my IP dry, my internal metering valve seizes shut. No fuel will get pushed out of the IP to the injectors. The only solution that I've found is to open the top of the IP (careful to remember how to reinstall it just as you found it) and wearing a brand new latex glove, I wiggle the metering valve to get it from unsticking. I've only had to do it three times in the history of my IP, but every time resolves my no-diesel issue. (Note, if you are a diesel noob, I don't recommend you opening up your IP. Take it to a shop and spend the $150. But if you are pretty technically or mechanically savvy, you could give it a shot.)

Yes, cracking the lines at the injectors, probably 1/4 turn. I'm quite savvy, so I feel pretty confident I can break the thing open. I was doing some research before I posted this thread about replacing the FSS. My thought was, if it isn't opening enough to let the proper amount of fuel through, maybe that was the problem. Fixing it myself with a $60 part is a lot easier to stomach than $700-800. But if you guys don't think that's the issue, I'm back to square one.

 

[genscripter]

If your FSS is clicking, then you probably don't have to replace it.

I'm talking more about the metering valve. It rests in the bottom of the IP reservoir, and controls the output of the IP. In order to access it, you need to open the top of the IP, and pull the cover off. Then with really clean hands (gloved), reach into the pool of diesel in the reservoir and fiddle with the valve, trying to work it back and forth. Then reinstall the cover (careful to realign the components on the underside of the IP cover).

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This post from FTE kinda explains it well: https://www.ford-trucks.com/forums/1406576-hard-starting-a-7-3l-turbo-hot-or-cold.html#post15790738

"The fuel metering valve is just a solid chunk of steel. It is round and fits in a bored hole with very close tolerances. It rotates back and forth with "no fuel" at one end and "full fuel" on the other. It's not something you'd want to replace. I'd check it for sticking and make sure it moves freely. I'd be more suspect of the linkage or the fuel-shut-off solenoid. I have never seen a fuel-solenoid actually go bad either and I watched them evolve three times since the early 60s. But the newer ones like used in our trucks can suffer from a metal plunger that sticks. It is just a metal rod that rides up and down inside a round plastic-lined bore and I've seen a few get sticky and catch at times . I have also seen solenoids short out but that is because of the rubber isolators where the electric studs protrude through the top-cover. Not the windings themselves.

If it was mine - I'd pull the top cover off and check the solenoid plunger, shut-off linkage and the fuel metering-valve for free movement."​

If I were you, I'd put that IP back on, check your components in the IP for movement, and then purge the air out of your fuel system. Then see if you get fuel at the injectors.

 

[icanfixall]

Welcome to the forum. If the fuel shutoff solenoid is clicking with on & off power. then its working. It wont half open either. Replacing it has risks but you tell us you are savy. Please do this "IF" you replace or remove the top of the injection pump.Make sure you can shut down the air to the intake. If you mess up installing the top cover the engine will go well past the stock rpm red line because the governor has been bypassed when you installed the cover on top.
You tell us you installed and removed the injection pump.If you did this with the gear cover and gear still attached to the injection pump you made a huge mistake.. But that can be corrected with help.
Now finally you need to know VERY LITTLE fuel comes out the hard lines when cranking and the engine must crank very fast to generate enough heat from compression to combust the diesel. you need 942 degrees in the cylinder to ignite diesel. Being a standard trans truck why not push or pull start it??? That gets the engine spinning fast enough to heat up the air in the cylinders to ignite the diesel. Any diesel will not start by slow cranking the engine. The faster we compress the fuel the hotter it will be. Thats just plain science acting right there. Many do not know this.

 

[ISPKI]

I will second what Mr.fixall said. I had a laundry list of fuel issues to troubleshoot on my truck when i got it and was shocked at how little fuel actually comes out of the injector lines, its about enough to moisten a paper towel.

 

[BlazeKeeper]

Alright, I got the top of the pump taken off, and this is what I found. I don't really know what I'm looking at, so here's a couple videos. Thoughts?

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[Thewespaul]

Looks good from what I can see on my phone screen.

 

[BlazeKeeper]

Update: After no luck, I took it to the shop and asked them to tear it down and tell me what it needed before they did anything. Apparently the seals and the advance piston both need replaced. All the more reason I'll never deal with Pensacola, no matter how good their prices are. Pricey fix, for sure. Hopefully I'll be able to make my money back if I decide to sell it. Time will tell.

Their price was about the same as sending it off, so I figured I'd save on shipping and just have them do it