Haulin_in_Dixie

I read over this whole thread and am surprised that no one mentioned a couple of things. The quick disconnect at the tank likes to leak and will do what your are describing. If I have half a tank or less and park with the nose up hill, it will pick up air. It gets it from the tank pickup system.

That being said I also had a problem one time after putting the engine back together with starting after sitting. Later I found a slight leak at an injector line. Fixing that made it start properly again.

A small leak in the return line will cause this also. Try one thing, get under it and reach up over the tank, find the fuel supply line with the disconnect. Move it around some to try to seat it. There is an O ring that slides over the tank pickup and it can get dirt etc on it. A leak is made worse by cold fuel and by low fuel. I'll bet that with a full tank you don't have the problem.

I think that there can be some problem with the actual pickup in the tank also. I had about 1/8 tank a couple of weeks ago and was going to get fuel. Stopped at the exit nose up for the light. Light changed, I started, turned the corner and lost the prime. Put five gallons in it and had a problem getting it to pickup. All of a sudden it caught and went to normal, 15 pounds.

I have found that a leak will drain the fuel from the supply circuit in the VP44. As was suggested, cycling the pump a couple of times will fill that section again and it will start like it had no air. If it is run out, the injector circuit also gets air and then you have to bleed it at the injectors.

Again, I would look at the tank fittings for a leak. Also wanted to mention, the copper washer keeps a fuel leak from getting into the cylinders. An O ring part way up the injector body keeps it from getting into the valve cover area. The injector tubes have an O ring to keep it trapped in the injector area. It is pretty well sealed.

Make sure you have no fuel leaks at the VP and the injectors. With the engine off and cold wash the joints down with brake cleaner. Then drive it for a while and check for wetness. Hard to see the lines at the VP in the back. Wonder if you took the lines off both ends when you put the injectors in. I have had trouble getting a good seal on the VP end of the lines and generally tighten them before the injector end.

ramlovingvet

I have seen the return fule lines fail and develope holes thats can cause this problem too. It was on a 96 but who knows?

HOHN

Thanks, fellas. I have been going around in circles on this one.

HID, my truck DOES do this even with a full tank.

When I change injectors, I never touch the lines at the VP. No need to.

I am starting to think that something at the tank is the real culprit. The reason is that I think back to how this all started, and it happened after I went off-roading really hard, then let the truck sit for 10 days in some bad cold weather.

I dunno if it was the cold or if it was the off-roading or what. It's mysterious to me that tightening the injector hold downs seemed to make it go away temporarily-- but this coincided with warmer weather, so it may not be the case. Since we got more snow today, I think I am gonna spray the brake cleaner, then check the tank fittings.

Justin

banshee

What kind of FP gauge do you have? My electric sending unit on my westach on my '01 started weeping, and it caused the same hard starting until I figured it out. Luckily the sending unit got bad enough and starting leaking fuel out one of the electrical posts, so I saw it and changed it. For the first few days it never put a drop of fuel on the ground, so it doesn't take much of a leak. If it's not on the gauge, you have a minor pin leak somewhere.

John

HOHN

My gauge is mechanical-- a Hewitt gauge from EEP. It doesn't seem to leak. It was sealed with thread sealant at all points, and I have no diesel smell in the cab or engine bay.

Maybe I need to try the talc method?


If you clean it with brake cleaner and let it dry (or blow it dry w/ compressed air), you can then dust areas with talc and it will show you even the tiniest leak.

We used pink talc to do this when I was a fuel system specialist in the USAF.

Justin

HOHN

Time to update my hard start condition, as it's been almost a year.

It's mysterious to me that I have been able to deduce two things about my hard start condition:

1) It only happens in colder weather. Once the weather warmed up, the hard start "magically" went away.

2) There's some kind of interaction between fuel level and the flatness of the surface it's parked on. The more nose-high the truck sits, the lower the fuel level has to be before the truck will lose prime.

In the last week, the starting had gotten REALLY bad, to the point where it would lose prime almost instantly, regardless of uphill or downhill attitude. I found that a fuel line connection on my Fitch was loose. Tightened it down last night and the truck SEEMED to start just fine. The fuel level is close to half (which is low enough to cause it no matter the angle it's parked), and after sitting for 20 minutes uphill (in my driveway) it fired right up.

When I parked the truck for the night, I backed it up the drive so it was nose-low (as has become habit in an effort to help starting).

This morning-- no dice. I had to crank and crank and crank.

So I'm effectively back to square one. While I was able to fix the FP gauge noise (needle valve) and also tweak the WG in my "wrench session" last night, I have NOT found the air leak!

You can only BEGIN to imagine the frustration.

I think I may have to just tear apart EVERY SINGLE connection in the plumbing from the tank to the VP and put thread sealant gunk on them. AN or JIC fittings like the Max Flow setup uses SHOULD NOT require this sealant, though.

I just can't see how the air leak is in my delivery system! I've gone over it so many times.

What would be the effect of a leak in the RETURN SYSTEM? What if it was small enough to allow air in, but not fuel out?

Keep in mind, that the first time I had this problem (last winter) it was BEFORE I installed the max-flow system. I also had a peculiar tank pressurization that accompanied that issue (the tank vent was working, too) and the fuel cap almost took off my nose when I refueled!

I'm almost to the point of picking up some stock injectors or 275s just to see if it makes the problem go away.

Anyone have slightly used 24V stockers they will part with for cheap?

Justin

gies

Justin -
I have a set of stock injectors, you are welcome to use them to see if that is the problem. I would need them back though for when I upgrade next. Shoot me a pm and let me know if you want to throw them in there and see if that helps. I'm in WYO for another 3-4 weeks so that should be enough time to tell...
good luck,
j

Haulin_in_Dixie

I don't have the time to re read the whole thread right now but these problems usually come from the tank pickup in the cannister. Can also be caused from bad sealing of the injector tubes, especially if the older ones are used. But the injector tubes will not cause the higher fuel level starts and level if the truck starts, that is usually in the cannistor.