hard starts after sitting/ possible VP44

[joeld79]

Ok I have been trouble shooting a hard starting/long cranking issue for almost 2 years now, owned the truck since 2006

 

2001 24V HO 

AIRDOG the week i brought it home and ever since

Edge Stage4 Jammers I think injectors 

Newly rebuilt NV5600 (ChaCh$$$ng)

196K

 

nose downhill, no problems

level, takes over night

nose high, takes a few hours

to require a priming sequence necessary to start the truck, worse in the cold weather

 

Lots of informative helpful threads out there and I have been through them all

 

Last night pinched just at the VP44 inlet and just after the T return lines from the head and the VP44 and closed the lines

 

This morning it still would not fire until priming sequence

 

Where would the fuel be going?

 

Is this a sign of the VP44 going bad?

 

No codes stored 

 

TIA

 

Joel

 

 

 

 

[joeld79]

So far...

 

checked all fittings for tightness and added extra fitting clamps or tightened

put system on air and visually checked all connections (nothing found)

replaced check valves at head and VP44

replace filters

trouble shot with pureflow tech support to eliminate airdog

pulled bed to inspect tanks and tank connections and air test fittings

 

 

Have not replaced o-rings so does that fuel or air leak into the head?

 

 

 

 

 

[015point9]

2 hours ago, joeld79 said:

...require a priming sequence necessary to start the truck, worse in the cold weather

 

 

 

 

 

 

Your info location says Seattle.  If in Seattle proper we haven't had low enough temps to effect starting...

yet imo.

Maybe I missed it but

How much Fuel pressure?  If you dont have gauge oriellys or auto zone has loaners that you pay for. Bring it back in 1 piece. Get $$$ back.  But so much info gained by knowing pressure, makes gauge very worth while.  

Overall sounds to me like problem hard to find, but should be easy fix.  

Depending on which airdog, easy to connect pressure gauge or at OEM filter cap.  

[joeld779]

14-15 PSI have a gauge 

[Tractorman]

4 hours ago, joeld79 said:

This morning it still would not fire until priming sequence

 

Just for clarification, does this mean you are cracking open high pressure injector lines to get the engine to start?

 

4 hours ago, joeld79 said:

Last night pinched just at the VP44 inlet and just after the T return lines from the head and the VP44 and closed the lines

 

I don't know that pinching off lines is a reliable test since you can't actually see if the line is completely closed off.

 

3 hours ago, joeld79 said:

put system on air and visually checked all connections (nothing found

 

Did you use a soapy solution to check for the leaks? 

 

I know that you are trying to resolve this, but many times fuel lines will leak air in, but not fuel out.  The fittings on the back of the head probably need to be taken apart and properly resealed.  I personally have never had trouble at that location, but many owners have. 

 

Your symptoms do match fuel draining back to the tank, especially the nose parked up hill part.

 

- John

[joeld779]

priming like 3 cycles of the lift pump bump

[dripley]

I have to agree with @Tractorman. The nose up/down thing is a red flag. It does not take much of a opening while pinching those lines to let air thru. I also curious what check valve you replaced on the back of the head. Mine has none, just the banjo blot connection.

 

The head and  return tee grommets were my problem many years back with those symptoms. About I year ago the same issue came up and I started growing oil about the same time. I changed out the injector o rings for the later and found a couple damaged connector tube o rings damaged and changed all of them also. No more growing oil or hard starts. My return lines were fine this last time.

[joeld779]

So I rebuilt the return T with cummins washers and still had hard starts. I replace the washers for the fuel return line at the back of the head,  when i changed the banjo fitting at the head i could only find 1 washer as i blindly removed it.  Can anyone confirm the correct washer number?  Still having hard starts but even worse now with the new washers at the head.

 

Never mind 

Edited November 15, 2019 by joeld779

[Tractorman]

@joeld779, I hope your problem is fixed when you get everything resealed behind the head.  I'm sorry, but I don't know the part numbers.

 

Some time ago I recall someone mentioning on one of these forums that he had similar symptoms and it turned out to be the input shaft seal on the VP44.  After awhile I think he figured out that fuel was leaking into the engine oil as well.  I hope this is not your problem.

 

- John

[joeld779]

Well i did find fuel in my oil and the level is up 

[dripley]

Try this 3963983. They are 12mm for 12v and 24v fuel system banjo bolts.

 

With the oil growing you might need some new o rings. Do you know how many miles yours have on them?

[joeld779]

ya I used that exact part number I have 2 new ones on there, stage 4 jammers with about 100k

[dripley]

You could pull the valve cover znd have a look with engine running. You might can see fuel leaking around an injector. Maybe pull a couple and see if the orings have flattened out where they meet the bore.

[Turbo_baer]

Just went through this on mine. It’s been an ongoing issue for a while in the colder weather after the truck sat overnight. Never and issue when the truck sat at work for longer periods of time. I also had a tapper cover leak that I repaired. Truck was good for 2 weeks...... then.......

 

I replaced:

 

straight cut orings on the t fitting

o rings on the return line at the vp44

new return relief valve on vp44

new fuel line and fittings from lift pump forward- 15 psi idle

new filters on the fass

 

still hard a hard start that was worsening, noticed fuel in oil.

 

replaced:

injector o rings- were VERY flat and came out easy, real easy

new crossover o rings

 

seemed to solve the fuel in oil issue

 

then:

new #4 injector line- was leaking at head after initial injector o ring change

new crossover tubes from BD diesel and orings- figured it’s was best as they had 240k on them and been through 4 injector swaps

 

so far so good! Truck runs a lot better all around. Power is back to where it’s supposed to be. Happy till the next issue arises. I’m 99% positive the injector o rings were my issue. Only time will tell if the oil level rises again, then it’s time to dig a big hole and burry it. 

 

[joeld79]

figured i wasnt alone on this issue thanks for the info, gonna look at putting the stock injectors back in anyway, let me tell you the looks i get from all these tree huggers in seattle

[Turbo_baer]

If they have been sitting for a while..... they may be stuck. I tried installing my old fbd 100s that were on the shelf for a few years. Started up and ran on 4 or 5 cylinders. Wasted $30 in seals and orings. If the injectors are working in the truck now just replace the seals. Very easy. Do it sooner then later and do a few oil changes to get the diesel out of there

[joeld79]

Ya they been sitting for 7 plus years, maybe ill order some rv's 

[joeld79]

So due to time constraints (single parent 2 kids) and against the advise given above I installed my old injectors.  They looked in really good condition and I need my truck back for work.  I primed the system via key bump 10-15 times and its starts to fire right away but then dies quick.  I repeated this 10-15 cycle of key bumps 3 times with same result.  Just curious if I should keep trying this sequence or if that is a sign something is stuck? TIA 

Edited November 22, 2019 by joeld79
pic

[dripley]

You might try loosening the nuts on the head at 1, 3, and 4. Prime the system then until you get a good flow of fuel to them and tighten them as they do, then keep cranking. It will run rough until all the air is cleared from the lines. Sounds like you are close to it starting. 

 

I should add if your old injectors have a lot time on them they could be in a fairly worn state. Went thru this not long back with flattened orings. Swapped some older ones that were not flat onto the newer injectors and it worked fine until I could some new ones.

Edited November 22, 2019 by dripley

[joeld79]

Got it fired up, I had the 1,3,4 injectors cracked but wasn't tightening them as they got fuel at first (derp)

 

Drove it around after letting it idle for a while and she rips! 

 

No more dirty Edge injectors that looked like they'd been in about 12 different trucks and smoked like a chimney 

 

Started her up this morning after sitting overnight and she fired up faster than a ***** in church

 

Thanks fellas!

 

Edited November 23, 2019 by joeld79