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No Fuel getting to injectors

21K views 22 replies 8 participants last post by  Stuart Perkins 
#1 ·
Hey guys,
Long time reader, first time poster!

I have a 1992 F250 7.3 idi diesel and I have been getting air in my fuel lines and it's causing the truck to die while running.

Currently I have traced the fuel line from both tanks, through the switch and into the lift pump. I noticed the fuel line had a small leak right were it attached to the lift pump. I added a hose clamp and tightened that down so it doesn't leak anymore. I replaced the fuel filter because it looked old and I didn't know when it was last replaced. I have also replaced the fuel return lines because they looked old and I noticed a few cracks in those as well.

Now I am trying to bleed the lines so I can get the truck started and see if I am still getting air in my fuel lines. My problem is that I have now drained my batteries twice trying to get fuel to the injectors but I have yet to succeed. I had noticed fuel bubbling up at a couple of the injectors but when I inspect the line it seems like it may just be air pushing through because no fuel is dripping out.

I'm stuck now and am not sure where else to look. I just bought this truck last year so unfortunately I do not know the history of when parts were replaced but by looking at the IP and would guess that it has been replaced withing the last 5 years. Also, the bubbles coming through lead me to believe that the IP is still working.

If my fuel lines were empty from my lift pump all the way to the injectors how long should it take me to bleed them through? Is there a way to get fuel back through the system without trying to start the truck and risking burning out my starter? Is there any other thing that I have overlooked?

I appreciate any guidance you can give. Cheers!
 
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#2 ·
you could have a air lock in your fuel filter that is stoping fuel getting to the ip
 
#3 ·
Did you fill the filter with fuel or a diesel rated additive? If not then your going to be a LONG time pushing enough air out to get it to start.

Crack all 8 injector lines at the injectors. Crank for 20 seconds and REST the starter for 2 minutes between cranks. As you see fuel bubbling out, tighten that fitting and keep up the cycle of starter/rest. It can take a LONG time, patience is key. Also make sure the tank your pulling from has at least 1/4 tank.
 
#5 ·
Hey Chuck, Some advice that was given to me was to top the filter off with some ATF. I did find out that the fuel level in my rear tank (only operation tank I have at the moment) was low, @ 3 gallons, and that its possible that air is getting into the lines from there. I have since then added @ 4 more gallons of fuel. I have loosened all 8 injector lines but do not notice any bubbling of fuel when I am trying to start the truck.

I got concerned and loosened a couple lines an the injector pump itself and although I have fuel going to the inlet I have no fuel coming out of the pump, this makes me cry a bit! Before I replace the injector pump is there anything I can do to try and fix it? Although the truck is a 92 the injector pump is probably the newest part under the hood. By the look of the pump I would guess that this had been replaced in the last 5 years.

I've driven this truck for over a year and it has never given me any indication that the IP was going out. On my last f250 the truck gave me problems for over a week before it finally gave out on me. Is it common for IPs to go out without any warning?
 
#6 ·
Some advice that was given to me was to top the filter off with some ATF.
That's far from being good "advice". If you're having a fuel and/or starting problem and you change the filter don't add to the problem, tilt the odds in your favor, at least fill it with something a diesel fires up and runs on----that would be diesel fuel.
 
#7 ·
Some advice that was given to me was to top the filter off with some ATF.
That's far from being good "advice". If you're having a fuel and/or starting problem and you change the filter don't add to the problem, tilt the odds in your favor, at least fill it with something a diesel fires up and runs on----that would be diesel fuel.
I agree, only thing that belongs in the fuel system is FUEL or a diesel rated additive.

OP: get a new filter and fill it with fresh fuel or SeaFoam. Then trst the fuel shutoff solenoid. On the top of the IP Drivers side Front connection. Apply 12VDC and it should click. Remove voltage and it should click again. No click, solenoid issue.
 
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#8 ·
The advise for the ATF was from an old timer and since I run BioFuel he told me that when I change filters I should fill it with ATF, start the truck and let it idle for a couple minutes to get the fuel in the injectors then shut it down and let it sit overnight to help degunk the injectorts...it sounds very much like the process I've read about with Seafoam, I just think that was too new of a product for him to know about. He's in his 80's and hasn't worked on diesels in a while.

I picked up a new filter and some Seafoam, I also grabbed a can full of diesel as well. With the new filter full of diesel I still get no fuel making its way through the pump. I also tested the solenoid by applying 12VDC to it and there was no click to be heard. At this point is there anything I may do to fix it or am I just looking at having to replace the IP?
 
#9 ·
I've read about with Seafoam, I just think that was too new of a product for him to know about. He's in his 80's and hasn't worked on diesels in a while.
That might be me, been on here since 2007, previously known as Bill1013, now Trucker87. At 89 still working on em.

All good advice above.

When cranking to expel air, keep a battery charger on the batteries. Takes about two days to recharge both batteries at 15 Amps charging.

Like said, 20 seconds start, 2-3 minutes rest.

If you have a tire valve cap that removes the valve stem, use it to loosen the Schrader valve stem on the filter to expel any air from there, close it when you get a solid stream of fuel while cranking. A remote starter button is your friend when doing that.

When you changed the return lines any disturbance of the hard lines from lift pump to filter and from filter to IP, the sleeves on those lines get hard over time and will let air in but not leak fuel. LP to filter takes a 3/8" sleeve, filter to IP takes two 5/16" sleeves, one at each end. Use a Dental pick to get the old ones out.
 
#10 ·
Haha... Trucker87, it was from a family friend so you are not to blame for this one!

I started to double check all the work I have done so far and I found that I did something wrong when I tested the FSS. after testing it again what I found is that if I remove the connector and plug it back in I do not hear any clicking noise. However I read in another thread that I can use a wire and make a jumper from the positive on the battery to the FSS post on the IP. When I do that I definitely hear a distinct click. I'm hoping this means that there is still hope for this pump. I have tested all the relays in the power distribution box under the hood and they are all working. Why would I not be getting power to the FSS connector? how would I test were this short is coming from?
 
#11 ·
Thanks for all the guidance everyone! After all of that what it ended up being a loos pin in the harness that was keeping me from getting power to the FSS. That was a lot of mind numbing troubleshooting for a needle in a haystack. And to think I was a couple hours away from spending a bunch of money on a new IP.
 
#12 ·
A diesel engine burns ATF well enough. The difference between putting ATF (or your favorite diesel additive) and diesel fuel in the filter is that, provided it comes from a clean container, ATF can be put in the filter directly, whereas diesel fuel would have to be filtered separately first (after all, whatever you pour into the filter, you pour in _after_ the filter medium). This is why the factory manuals always instruct you NOT to put unfiltered station diesel fuel into the filter before installing it.

If you want to be completely "orthodox" about it, you could choose a diesel additive like one of the Power Service or Stanadyne products. At least the wouldn't need to be filtered first.
 
#13 ·
I fill mine with SeaFoam when I change filters.
 
#14 ·
A diesel engine burns ATF well enough. The difference between putting ATF (or your favorite diesel additive) and diesel fuel in the filter is that, provided it comes from a clean container, ATF can be put in the filter directly
Really, and as a full time diesel mechanic you've researched the flash point of ATF compared to diesel fuel? Also as Trucker87 has said more than once, it's not too difficult to pour clean diesel into the outer filter holes so it flows through the filter media.
 
#15 ·
As an owner, I have to wonder how important/relevant flash point is of a substance that DOES burn in our engines, and would take literally seconds to consume. As a reader of the FSMs, I tend to refrain from doing things the manual instructs, in all capitals, not to do.

As an ad hominem attacker, have you researched the flash points of every diesel additive on the market, that diesel owners use every day?
 
#16 ·
Try cracking the small triangular plate on the side of the pump if no fuel seeps out you might have a faulty fuel shut off solenoid or the shut off valve has jammed.
 
#17 ·
The OP did post that the issue has been resolved.
 
#18 ·
Still having trouble getting mine to start again after changing the filter. Topped it off with diesel...poured into the outer holes only...cranking it produces a pulsed stream of fuel out the schrader valve, which makes sense since it is a mechanical lift pump.

I loosened the first injector line, but got no fuel out of it. Do I need to actually pull the line to break the seal? What is the likelihood of needing new o-rings if I do?

Unfortunately, the only thing I hate more than the smell of gasoline on my hands is the smell of diesel on them. :(
 
#19 ·
If you're going to work on these things you had better get used to the smell of diesel.
As for your priming troubles, as Chuck said above, it requires patience. crack lines loose following the flow of fuel and see if it is there. once you reach the I/P, then 20 seconds on the starter, two minutes off--repeat till it fires off assuming it is getting through the pump
 
#20 ·
That is my main thing I wish to accomplish today. Unfortunately, it is more than just the smell that bothers me. Once I've had all of the Petro fumes I can handle, my eyes will essentially swell shut. I don't want to "work" on diesels, but I need a reliable truck for my farm, and don't have the $ to pay someone to fix it right now. All of my $ are obligated to medical expenses for my daughter for the time being...and then some.
 
#21 ·
Henry Lives! Yes, I name my vehicles. Not sure if he is Henry Ford or Henry Wadsworth Longfellow...he is certainly a long fellow.

Anyway, cracked the injector lines loose on the left bank and the front two of the right bank...the back two required removal of stuff I didn't want to remove unless I had to. Cranked until bubbles stopped and liquid was oozing...and it started. Shut it off quickly, tightened all back down and reassembled the air cleaner. All is good now. No drips. No smell. No imminent risk of fire.

It always seems that right after I put new tires on a vehicle, something else goes wrong. :/
 
#22 ·
If you're that allergic to diesel, you might try using nitrile gloves while workig on it. It won't get on your hands. A dust mask might help with the vapors.
 
#23 ·
It hits me in the eyes. I just have to meter how much exposure I get in the course of a day. Fortunately, it didn't take much to get Henry going again.

I have a very hard time doing things with gloves on...sweat too much, and hampers my sensory input too much. A mask or goggles are too confining...I can barely do reading or safety glasses. That is a psychological thing I think. I manage by doing as little as possible with fumes involved.
 
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