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More fuel system woes :>(

Crankme69

Crankme69

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All right it's time to ask some questions.

Truck sat for 2 days & when I started it today it must be getting air in the fuel system from somewhere. Yea it will start but there is no way this thing is gonna start when it's zero out.

Clear tubing where to put it? On the front/top of the IP or is there a better spot...?

Should I attempt to place a pound or 2 of air pressure on the tank through the return lines to search for leaks is this a bad idea got any better ones?

I have the new 25ft roll of Bio fuel hose so I will replace the tank side to the LP & any of the lines that look suspect. How do I check the top of the tank or worst the line inside the tank that attaches to the sock for leaks?

I'm ready to pull the tank, but would like to have some idea(s) of what I should gather part wise before I do it.

Friggin old chit :mad2:

TIA

Greg
 
Have you checked the bottom of the fuel filter manager? The heater's o-ring are known to age and gets hard and leak slowly.
Introducing air into the system.
 
Put that clear tube on the top/front of the IP,you can permanently leave it there.
Mine is on it for 3 years already.Its great for diagnosics.
Run the engine till the tube is full,you should not have any airbubbles coming trough in a healty system.

Check that tube first thing in the morning before you start it.It should still be full of fuel,there is only 1 tiny air bubble allowed in the very top.

I advise you to get an in cab fuel pressure gauge.IMO it is the first best mod you can make.
The tubing in the tank are usually not rusted out but the outside is a diff story.
A few LBS of pressure in the tank wont hurt.
 
Going to head over to ACE hardware in a few minutes to get some clear tubing for the IP return line...

Bottom line if the sender is not tightly sealed to the tank should it really matter? I can't see how that would introduce air into the LP or fuel system? I mean what am I missing? I can understand how the LP feed line or even the LP feed line that runs down into the tank itself could provide a source for air to be drawn in but the sending unit on the top of the tank...I don't see that being any different then running with the cap loose...??? Am I missing something?
 
holes in the tank wont cause air intrusion, like you said its the same as with the cap off. But without a cap or a hole can cause the fuel to be less stable in the tank where is allowed to slosh and foam more. The closed system would achieve a slight vacuum as fuel is consumed. Fuel goes away and not displaced by any more air. The cap prevents too much vacuum. The fuel expands some from heating up, as well as any air that was in the tank when put the cap on, but its not more displacement than removing 10 gallons of fuel.

A hole in the the tank or removing the cap may relieve air intrusion a bit though, because with no vacuum in the tank the LP would not have to pull as hard, thus lowering the vacuum in the fuel line and relieving a pin hole between the pickup and the LP.

So you are correct a poor seal around the pickup wont cause air in the fuel lines, but it might make fuel get colder allowing more moisture and air into the tank and also more foaming.
 
If you don't have any bubbles, than it could be a drain back problem. Over the course of the night you should be able to tell if fuel is draining back or not.
 
Crankme69 said:
All right it's time to ask some questions.

Truck sat for 2 days & when I started it today it must be getting air in the fuel system from somewhere. Yea it will start but there is no way this thing is gonna start when it's zero out.

Clear tubing where to put it? On the front/top of the IP or is there a better spot...?

Should I attempt to place a pound or 2 of air pressure on the tank through the return lines to search for leaks is this a bad idea got any better ones?

I have the new 25ft roll of Bio fuel hose so I will replace the tank side to the LP & any of the lines that look suspect. How do I check the top of the tank or worst the line inside the tank that attaches to the sock for leaks?

I'm ready to pull the tank, but would like to have some idea(s) of what I should gather part wise before I do it.

Friggin old chit :mad2:

TIA

Greg
Click to expand...
I would not know how you would get to these lines back there without dropping the tank.
 
Ok so here where it stands after today's diesel bathing.

New Walbro LP with new rubber fuel lines from the tank all the way to the FM. The old LP had seen better days and the metal LP feed & discharge lines were at the end of there life also. I didn't see any obvious leaks but the lines were all in bad shape.

Now we'll see what tomorrow brings. The last 3 weekends I have spent under this truck, this chit is gonna come to a halt one way or another...
 
Have you got the pre-prime going? Since OBD2 vehicles have pre-prime during WTS, that likely covers up several similar issues until things are really severely bad.
 
No I never did that. I'm anticipating that will be next now that the LP is no longer stock it'll burn up the OPS next. You know how I plan to fix that...that OPS is gonna be for indicating the oil pressure only when I'm done.
 
Crankme69 said:
I installed the clear tubing on the IP return line...NO bubbles nutta nothing zero WTF?

I'll check it again tomorrow morning I guess.

This truck is really trying my patience, it's begging me to be replaced!
Click to expand...



when you own an old truck you gotta expect to have maintainence issues,if this is all it takes to make you sell it you better start driving new trucks. just saying
 
I hear ya believe me if I didn't like the truck as much as I do it would have been gone long ago...

FYI I have not purchased a new vehicle since 1990 & that was also the last time I had a car payment so yea I cry some but I hate payments so...
 
The OPS relay mod is not that tough to do and would keep things nearly stock,adding a pre-prime like mentioned would only take the addition of a starter bump button on the dash wired to the relay or OPS circuit to close the relay before cranking.

With no air in the clear line,I would start looking at the glow system for starting problems.
 
One teeny tiny bubble in the top of the clear tubing this morning. It started right up no coughing or stumbling very little smoke & ran like it used too. Now I will leave it set for a couple of days & put it to the real test. I think I got it fixed, we'll see.

The glows are new 7 new Duratherms one would not come out, verified power to all. Might get ambitious some day & go after the one that's stuck...we'll see.

Thanks all for the replies I'll post up in a few days let ya all know if it's finally fixed or not.
 
Crankme69 said:
I hear ya believe me if I didn't like the truck as much as I do it would have been gone long ago...

FYI I have not purchased a new vehicle since 1990 & that was also the last time I had a car payment so yea I cry some but I hate payments so...
Click to expand...

I finally got my truck running after a bout of line bleeding, battery draining, starter ruining fun. During that period of time i was tempted to throw it into the woods, set it on fire and collect the insurance...but then i remember my insurance doesn't cover that :p

I've said that about every truck/car i've owned and each one of them holds a fond place in my heart. Each one i would kinda like to drive right now too.
 
Crankme69 said:
One teeny tiny bubble in the top of the clear tubing this morning. It started right up no coughing or stumbling very little smoke & ran like it used too. Now I will leave it set for a couple of days & put it to the real test. I think I got it fixed, we'll see.

The glows are new 7 new Duratherms one would not come out, verified power to all. Might get ambitious some day & go after the one that's stuck...we'll see.

Thanks all for the replies I'll post up in a few days let ya all know if it's finally fixed or not.
Click to expand...
Exellent,it won't get any better than that.
 
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