I have a suspicion I may have VP problems.

But no codes with a good scanner.

I know these pumps can be tricky.

 

Truck starts immediately and quits after a second.

Try and start 2nd time - does the same thing.

3rd try, finally starts and stay started but runs rough for a 7 seconds then clears up, runs fine.

Drivability is normal .

 

Point nose down hill - no improvement.

 

I installed a Fuel Boss about 500mi ago and it has been great.

Cleaned pressure valve in pressure line (included w/Fuel Boss plumbing).

New crossover tube O-rings and injectors 1500mi ago.

New return T O-rings, new banjo washers.

Triple checked pressure and return line for leaks.

 

The only thing I haven't done is lift the bed, check draw straw V and connections at the tank.

 

I have several tunes downloaded for the Quad.

There are some that the Quad doesn't like (surging, VP gets noisy then quiet).

I thought that was kinda strange that the truck didn't like those.

However some tunes work fine.

 

Anyway, this is my dilemma.

Anyone have the same experiences?

 

 

 

Codes are usually of little help with a dying VP. They'll tell you when it has died, or in the case of the 216 code it could go for years before quitting. Check BlueChips VP44 diagnostic page for some good reading if you have not done so.

10 minutes ago, dave110 said:

Codes are usually of little help with a dying VP. They'll tell you when it has died, or in the case of the 216 code it could go for years before quitting. Check BlueChips VP44 diagnostic page for some good reading if you have not done so.

Thanks Dave,

I've read their page several times.

Other than making sure the tank connections are healthy, maybe doing the clear fuel line between the filter and VP would help give insight.

 

The truck has 166k on it, VP is original.

I've wondered if the VP has an internal air leak?

Low voltage and electrical noise in the system cause a lot of problems. The grid heaters are a heavy load when first started.

Grids have been disconnected.

Truck is garaged so cold temp isn't an issue.

WTS light operates normal.

AC noise in check with new diodes a year ago.

8 minutes ago, Great work! said:

Low voltage and electrical noise in the system cause a lot of problems. The grid heaters are a heavy load when first started.

 

I had hard starting issues about 6 weeks before mine failed. Got 216 code when the idle started messing up. Cleared it and came back 3 days later when the pump failed completely. Checking out Blue Chip Diesel's VP trouble shooting guide is good advice.

 

Appreciate the advice!

 

I've read the Blue Chip guide several times and I've done most of the checks.

Several months ago I had a siphon/hard start problem from inj. and crossover tube O-rings,

but this acts differently.

 

 

4 hours ago, Octafish said:

maybe doing the clear fuel line between the filter and VP would help give insight.

 

That's what I'd do. Sure sounds like an air leak to me. I'd suspect the manual LP or the draw staw. Tough to say which one. Clear hose trick would tell you if there's air in the lines.

My brother's VP never fully died, but never ever threw a code.  For years it would have fits of dead pedal.  Real randomly and intermittently.  Eventually it would have dead pedal until it warmed up.   Once warmed up, it would run fine, but never threw a code.  I swapped nearly everything except the VP with items from my truck.  Nothing ever followed it.  So we put a VP in it and  it has been fine.  So hard to say if it was a solder on the board or sticking timing.  But either way, it was the VP and no codes, so the limited programming never saw the error to report it.

I know you hate to throw a vp at the problem.  I do anyway.  Keep searching for it.  your issues sound a bit odd, as you have narrowed it to a pattern.  Try some variables on top of that (block warmer) (bump starter 3 to 4 times before first start  etc.)  and see.

 

Good luck

Hag

2 hours ago, Haggar said:

My brother's VP never fully died, but never ever threw a code.  For years it would have fits of dead pedal.  Real randomly and intermittently.  Eventually it would have dead pedal until it warmed up.   Once warmed up, it would run fine, but never threw a code.  I swapped nearly everything except the VP with items from my truck.  Nothing ever followed it.  So we put a VP in it and  it has been fine.  So hard to say if it was a solder on the board or sticking timing.  But either way, it was the VP and no codes, so the limited programming never saw the error to report it.

I know you hate to throw a vp at the problem.  I do anyway.  Keep searching for it.  your issues sound a bit odd, as you have narrowed it to a pattern.  Try some variables on top of that (block warmer) (bump starter 3 to 4 times before first start  etc.)  and see.

 

Good luck

Hag

Thanks guys,

 

I don't run an electric pump with the Fuel Boss so bumping the starter doesn't help.

But the stand alone mechanical pump has been fine for several months.

 

I tried the block heater with no difference.

However my garage stays about 48-50 degrees.

 

My VP may be original.  

I bought the truck with 140k so I don't know the history before that (however the old man I bought it from said it was original).

But I've always suspected a short VP life after finding rust in the banjo connections on the pump when I first bought it.

Truck must have set for  while.

 

The "start then die 3 times" thing has got me kinda puzzled.

When I had the suction side leak, you would have to crank for 5 or 10 sec and then it would start.

Very different from what I'm experiencing now.

 

I'm going to do the clear fuel line trick and see how that goes

 

 

Grrrr, Sorry about that and read you had a boss, but didn't register.  I was just trying to clear the lines of air if that happened to be the problem.   The clear line would help since you cannot pre load the lift system easily.

 

Look at the power/communication connector on the VP.  If it is original, there will be a tattle tale tape around the lock on the connector.  if it is still there and intact, guaranteed to be original vp.  broken definitely a swap, missing, well adhesive only has a limited life so unknown until you look closely at the pump and see if it has some rebuild info on it. 

 

try block heater on it.  try cycling the grids extra.  I wonder if the timing just can't keep up with the change during start to idle.  Need to look closely with a scanner.  something stupid like the IAT being waaay off, or map sensor telling a stupid story.  They can fail and not be out of range.  The programming doesn't use logic to figure if a sensor is bad.  If the coolant temp is 40 and the intake air is 175 and the boost is 10psi at start up the program would try to chart a timing /fuel map for that condition.

 

Good Luck!  I agree, I wouldn't condemn the VP yet.

 

Hag

 

 

Thanks Hag.

I'm not seeing anything odd with the sensors so I feel pretty good about those.

 

I'm trying to understand the dynamics of why  my truck will start immediately, run for a second or two, then die like the fuel was shut off.

Just seems odd for a no fuel to injectors situation.

When I had an air leak, you would crank for 7 sec then start. 

This feels very different.

 

I'm going to do the clear fuel line trick when it warms up this weekend.

 @Octafish Are you monitoring fuel pressure during these cycles, 

17 hours ago, 01cummins4ever said:

 @Octafish Are you monitoring fuel pressure during these cycles, 

Yes,

Pressure appears normal.