Well, I did check the lift pump, and as I was expecting, it spit out a reasonable amount of fuel. (I don't have a pressure guage to check if it really was 5~7psi or not)

I got at the engine, opened up a few injector lines, and once they started dribbling fuel, I closed them back up.

Then I turned the engine over one more time and heard that wonderful rumble...of my engine turning by itself....a little rough at first, but just the same it sounds pretty good about now!

Thanks for all the help!

I do have one final question...about re-tightening those injectors...I think I can guestimate something like 25~30 ft/lb, but if you have a chance, let me know if the proper number is significantly higher/lower than that. Without a torque wrench (and I don't have one), I'm probably not even calibrated within than +/- ft/lb anyhow, so as long as that is close, I'll just leave it as-is.

 

The roughnes was the last of the air getting out of the fuel system. Great to hear it is running again. Keep us informed.

 

If they are not leaking fuel, I say leave them alone.

Glad to hear it is running again, do stop in and join the fun now that it is running.

 

Last installment, I was feeling quite satisfied with myself at being able to fix it (with help anyhow), and the van started just fine.

Three days later, it didn't start again. Probably air in the fuel again. Unfortunately, this is our only moterized vehicle, and we need it...and I didn't have time to fix it in a timely fashion, so it got towed to the shop. I've heard second hand reports of what is going on.

They bled the fuel lines and got it to start, but couldn't figure out where the air was getting in.

They are afraid that it might be a leak in the injector pump, and it sounds like replacing it would cost something like the value of the van.

I'm also starting to wonder more about this--I don't think there ever was water in the fuel, and the starting problem was always after the van had sat for a while, so if air was making its way in through a pinhole somewhere, it would have had time to get enough in there. On the other hand, if there is a pinhole letting air into the high pressure system, how come fuel isn't spurting out all the time?

Any ideas what else it could be or what the cost for replacing the high pressure pump should be?

Thanks

 

I hate to stear you away from a fuel problem, but... How fast is the starter spinning the engine?

I just chased (for 2 months) what I thought was a air in fuel, or bad injection pump only to have a new starter fix my woes.

The local parts store did an amp and voltage drop test and it tested good. I thought it was turning the engine just fine, until one day it didn't turn it at all. When I put the new one on WOW what a difference. It is running before I can get my hand off the key.

It's just a thought.

 

An injection pump will cost about 450 dollars and it will take a couple of hours to change.

I fthe leak was in the high pressure side of the pump, you would have fuel spraying out.
The pressure on the high side is measured in thousands of PSI.

Air leaks in the return lines can empty the filter.
When you crank the engine it sucks the air into the IP which pumps the air into the injection lines.
Since the volume of fuel injected is small it can take a long time to get the air pumped through the system.

Do you still have the return line going to the filter?

Several people have changed from the mechanical fuel lift pump to an electric one to eliminate air intrusion problems.

 

I had a problem with a truck that had a hole in the dip tube in the fuel tank. I would not start well after it sat for any length of time if it was under half full.
Also for any truck with a little air in the lines, if you hold the throttle to the floor while cranking, it will start much faster by forcing more fuel through the lines. Just my two cents worth

 

Well, the starting motor seems to be good--at least it sounded like it was turning the engine over just fine. Well, I did do a BUNCH of starting and running the glow plugs in the process of bleeding fuel & trying to start, and I think my batteries are running down a little, so it may not be spinning quite as fast, but the starter still seems OK.

As for replacing the IP, I'm wondering if the garage is giving us an estimate that is a touch on the high side for it. I've got an E250 van, not a truck, and I'm wondering if the way they shoehorn the 7.3L engine into the van chassis makes it harder to get to the IP to replace it. I'm guessing it is near the fuel filter, which is probably the least accessible part of the engine--in the middle between the part of the hood that opens and the removable doghouse in the passenger compartment..

When I get the vehicle back from the shop, I'll take a look and check on the fuel return line(s). I've got two fuel tanks and a switch to change tanks. (Factory installed, I'm quite sure) Do I need to look for two return lines and a valve as well, or would the return line go to only one tank? How would I go about looking for an air leak in the fuel return line?

And while I'm thinking about it, could the dual fuel tank arrangement change the situation I'm working on?

 

Air leaks are not noticeable because air is a smaller molecule than fuel. Fuel probably won't leak out (telltale sign) but will leak air in thru very small cracks in hoses on the engine and fuel system. I had a fuel return line which was rusty and it was getting hard to start. Replaced the rusty area of the line with a rubber fuel line and it started right up like new. So rust will let air in to the system as well as cracks.

 

That is interesting.....Pinholes too small for fuel to go out could let air in. Never thought of that one, but there sure is a difference in the size of the molecules, so I guess it is possible. I'll definately take a look at the fuel return line(s) next time I'm messing with it.

Now that I'm thinking about it, there may have been a gradual change in the van too: Since we bought it two years ago, it has started a bit rougher--more smoke and running rough a bit longer before it settles down, although until last month, three attempted starts ago it always turned over just fine.

I always attributed that to buying it in Florida where it is always hot (and I didn't even know it had a block heater installed!), and moving it to the Pacific Northwest where it is pretty much cool and damp most of the time, so the engine block at startup is 40~70F instead of 70~100F.

I suppose that getting hints of air into the fuel could have contributed to that too--does this sound likely to anybody else?

 

If the fuel return lines on the motor are painted gray. They are original. Need to be changed. When you take one off it probably will be brittle/stiff. And when you bend it it will sound like it is cracking.

 

Well, the van is finally back from the shop, and they couldn't figure out anything that they could do which wouldn't be exceeding the value of the vehicle, so here's my status as of now:

1. I can get the van started by bleeding fuel out of the injectors when it won't start.
2. The shop was able to get it to start by taking off the air filter and pouring fuel into the manifold.
3. The shop claims it doesn't prime the way it should. (I do not doubt them, however I haven't figured out an obvious way to confirm this)
4. The shop claims there is a fuel leak near the fuel filter. I know I spilled fuel all over the place below it, but haven't confirmed a current leak.
5. Perhaps the most "interesting" thing about the failures is that when it has sat for too long (week? day?), the engine turns over, runs for about 5~10 seconds, then dies and refuses to start again. (I believe the guy at the shop was puzzled by this) My interpretation of it is that the leak is a little ways before the injection pump, and the lines have enough clean fuel to get started, but then the bubbles make it up where they cause trouble very soon after.
6. Based advice earlier in this thread, when I have a chance, I'll try to find the fuel return lines and see if they need replacement, and I'll do that if needed.

My questions for you forum wizards are:

• Pouring a little diesel into the manifold sounds easier than bleeding the injectors. How do I identify the manifold and where within it should I pour in fuel? Or does that even make sense?
• Is there a way without buying too much equipment I could check or test for leaks?
• What does it sound like my problem is now--Is there anything else I should try next? (Besides replacing the return lines?)

 

Nothing off hand because you got it started right away by pouring fuel into the air intake so glow plugs must be working. Has to be the air letting the fuel return back towards the fuel tank.

 

Like I said before I is quite possible you have a leak in the dip tube in the fuel tank. I had that same problem when mine had a hole in it. Try switching to the other tank for a while and see if it still does it. Just my opinion

 

Hello again folks....

I've decided to just bite the bullet and replace all the fuel return lines, but now I need to find them!

Looking at the engine, I see the 8 metal lines going from the pump to the injectors. On each side I see short lengths of rubber hose painted greenish-gray (like the rest of the engine) going between the injectors, plus a line going off on both the front and the back. The ones going off the back snake around, and are joined to a newer looking black hose going to a metal line and then to something which (presumably) goes back to the tank(s)

The front is harder to get at and I haven't figured where the lines coming off the front injector go yet. Is this part of the fuel return line and do I have to replace it too?

All these lines have cheesy looking spring clips holding them onto the injectors (which I won't trust to fit the new hose right, and even if they do, probably won't hold well once they have been touched.

Am I finding what I need to find here? My next stop is going to be to the auto parts place to get a bunch of fuel line and decent clips/clamps....after I measure it.

I'll see if I can get a picture up here--the Forum software gave me grief last time I had a pic, but I'll try to put it up in another comment.

Thanks Everybody!