Engine/Transmission (1998.5 - 2002) Fuel leak down issues, still.

[Froadin]

This has been an ongoing thing for my truck for the last half year, or maybe a bit more.

I injured my back and hip last year, so I haven't been able to spend a lot of time leaning into the engine bay.



History, nothing had really changed recently when this started. It basically would have the typical no start, let the LP run it's cycle once or twice, and it starts. After it's running, it would restart just like normal. As the days went by, the time needed for leak down to occur grew shorter. It started around an hour needed before it happened, but got to the point that 10 - 15 minutes would be enough for a no start.



I changed out ALL my inlet fuel lines from the vulcan draw straw, with a straight run to the LP's on the frame (took out the stock line that goes next to the tank and ran all 1/2" line).

All line is 1/2", all fittings are good, and all o-ring seals are new.

After that, I replaced the fittings on the T in the return line because they showed a little seepage. This helped a little, but the problem remained.

I have checked and replaced any line or seal in the fuel lines, both inlet and return.



I pressure tested the valve on the VP, opens around 14psi like it should.



My back was feeling good enough to take out the injectors a couple weeks ago and had them tested. Two of them were bad, but no surprise there.

Right after I did this, it started back up like normal. No leak down issue. Actually, it was the opposite in that if I had the LPs running with full pressure, it wouldn't want to start as easy. GREAT, like it should be!

But that didn't last long.

It still has the leak down issue, but it isn't AS hard to start now. This also might be because it's warming up some as well.



Ok, what's left?

The tubes looked fine when I did the injector install.

I put back in my stock injectors. They need a good cleaning, but they never had any leak down issues when I had them in before.

I am waiting on Don M to finish moving so I can get my injectors worked over, so I am stuck with the stock injectors for now.



Would the o-rings on the injector tubes even be able to cause this?



And what other component might I be overlooking?



Should I replace the valve on the VP anyways? This keeps sticking in my head, but it doesn't make sense when it passes the pressure test.



Btw, this only happened a while after the HRVP44 install. Never on the stock VP.



My back is getting better, and I REALLY want to get this issue fixed!

 

[Missouri Mule]

Just bringing back to the top!

 

[JAG1]

I had this same problem once. Happened several times.

I thought I had tightened the fuel filter cap almost too tight, was afraid I'd break the plastic cap so when it felt tight enough I stopped. It kept drawing air loosing prime, so I finally got out the torque wrench and tightened the filter cap to specs. Was able to get almost a full turn before it showed the right ft lbs. (forgot now what that is) it solved my problem and never had the same problem again.

 

[kkreigh]

If you still have the stock fuel filter assy on your truck You need to check the fuel filter drain valve. Dodge mechanic told me they have a rebuild kit available for them. This is the valve you use to drain water out of fuel filter.

 

[Froadin]

I tightened the snot out of the fuel filter cap.
I haven't set it to torque yet though.

Hadn't thought about the drain valve though.
Any idea where it's leaking at on or around the valve?

 

[JAG1]

I'm never going to rebuild Dodges drain Valve. I'll just leave it open and put on a high quality fuel shut off valve. They have stainless valves if you want the best.

Almost forgot, if you have the stock pump, check to see if the three bolts on the top are tight. I found mine loose from the factory, was leaking there.

 

[AllianceDiesel]

Have you changed the connector tube o-rings have seen them with a lot of miles on them crack or become flat, also have seen brand new ones get pinched when getting installed and get cut, causing them to leak off pressure.

 

[csutton7]

this is usually the overflow valve, although the crossover tube orings(like just stated) can be the culprit or the injector orings or injectors themselves--- at this point I'd do the crossover orings and then I'd change the overflow valve if that didn't fix the problem---then because of all you've done it could be the VP going south---chris

 

[kkreigh]

They are leaking on the actuating rod that runs down from the handle pivot.

 

[Froadin]

I planned on getting new crossover tube o-rings when I get my injectors worked over.

When I recently swapped injectors, it 'almost' went away for a very short period of time. It was definitely better. So something I did obviously affected the leak down issue.

Good things to watch out for here! I will be checking into these things as I can.

Any more ideas?

 

[JAG1]

Hey Froadin, why not drain all the fuel out of the fuel lines, disconnect the line back near the tank and pump no more than 10 psi air into the lines. you could use soapy water on the outside fittings to look for bubbles.