dkenny

a couple of weeks ago I installed new, slightly larger injectors, been running fine..

until today..
started fine this morning..drove my first job site..no problems..notice the fuel pressure around 10 instead 15-20. I didn't think much of it since it was over 10..
went to work..got the job done..and paid
went to start the truck and leave..it did..run fine for about 75feet..then died..
trying to restart..it would fire but not stay running..NOW WHAT! I did utter non publishable words.. several I tried..always the same..

call my wife to bring my other truck so I could take my work trailer home and call a tow truck..

finally got the truck home..no start..cranks fine..no fire..NONE...
check for codes..NONE!!

tried to bleed the VP..
I have fuel from the lift pump at the input..but almost none on the lines
leading from the VP44.. and at the head..

at the moment am I wrong in thinking the VP44 died..what else should I check. the blue wire with the red tracer has no voltage..

if its the VP.. I've changed it before..not too hard really.
if I go with Blue Chips Special X..with the large injectors I just installed(7X0.009) will it smoke a lot more? will I gain the 22hp plus the 75 from the injectors..so I should be around 310hp?? I would like this..

-dkenny

SIXSLUG

Sounds like you are diagnosing correctly but odd no death code if that wire is empty...

My first thought was fuel starved, gelled, blocked line, plugged filter etc.

How about the ECM? Just not throwing any codes makes me suspect that....

dkenny

ecm replaced last year..it ran this morning..

at the moment 20 some psi from the Airdog..and fuel at the input..

not cold enough for gelling..40ish and no biodiesel in the fuel..no WVO either

thanks for the fast response..

-dkenny

patdaly

Ok, fuel from the lift pump, no codes ( from a scanner, correct? )

This is from blue chips troubleshooting.

Note, all you should need is 12V to start...........

NO START – TEST #2
FUEL SYSTEM ELECTRICAL TEST

Next test the electrical wiring and verify that there is battery voltage getting to the VP44 with the key in the “run” AND ”start” positions. Remove the big plug on the back of the injection pump by wiggling the plug with your right hand pulling toward the firewall and the left hand pulling the indented locking tab toward the fender. When you have the plug in your hand, hold it so it looks like a smiley face, with six pins below the smile and three pins above. Using a test light or voltmeter with its ground connection on the engine, verify battery voltage on the bottom right pin (pin #7, which is a red wire with a light green tracer on a Dodge), during both “run” and “start” key functions. Then verify the ground on the bottom left pin (pin#6, which is a black wire with a tan tracer on a Dodge), by doing the voltage test again at pin 7 with the ground connector of your test instrument on pin 6 in the plug. If you see no voltage then, it means there is no ground! Use only pin positions, not wire color, when diagnosing a Ford or Freightliner. If you don’t have power at the plug, check the fuse in the PDC (Power Distribution Center, aka fuse box under the hood) for the fuel system, and if that is good, check fuse #9 in the fuse box on the left side of the dash. If they are both good, then try swapping the fuel system relay in the PDC with the one for the horn. Hopefully you find your problem this easily, but if not, get out the schematic for this circuit. If you don’t have one, go to ALLDATAdiy.com . If you have battery voltage on pin #7 in both key positions, and a known good ground on pin 6, cut the black tape off the VP44 plug harness to access the wires going into the plug and reinstall plug. On a Dodge find the light blue wire with a red tracer (pin #5 on other trucks) and verify that there is NOT battery voltage there during either the “run” or the “start” functions of the ignition switch, WITH THE PLUG PLUGGED IN. The ONLY time there should be battery voltage on pin 5, is for about three seconds after turning the key to the “off” position. If there is battery voltage there at any other time, the engine is being told to not start or run, by a ****** off ECM. This test is accurate 99% of the time in my experience. It is not unusual and OK to see low voltage, like .2 - 2.4 volts at pin 5. The important thing here is to NOT have battery voltage there, and if you do have it at the wrong times, I have found cutting that wire fixes the problem and running the truck forever that way, causes no harm!

dkenny

I've not verified the voltage on the pins during the run and start..but it was running before it wouldn't

when I left the client it tried to start but wouldn't stay running..more of a cough and spit..die..over and over..

when the tow truck came about 3hrs later..no fire..none..

and no fuel out the injectors lines now..even at the pump output

-dkenny

DIESELWRKS

if i was hearing right.
You first noticed just over 10 psi, had it die and not start and run.
you then said you had at the moment 20 psi? that is a huge swing in psi, something isn't right. still if no codes are popping up. and you are bumping the ignition to cycle the fuel and no fuel. have you pulled the line at the airdog on front side and cycle the key to see if its pumping fuel? If it is something is going on with filters. what type of filter do you have. filters on the airdog? no airdog filters and using stock filter? or using both filter on airdog and stock filter?

dkenny

its was running fine with 10psi..
I got to my job.turned it off..then it would stay running when I tried
to leave about 1hr later.

now it does fire at all..

airdog filters only. I've opened the line at the injector pump input..I have fuel.
I've open the injector lines..no fuel when cranking

and no codes..

-dkenny

jrs_dodge_diesel

Do you have all 6 injector lines cracked open? If not, crack open all 6 and try starting again and see if you get fuel at any of them.
If you don't get any fuel or just a litle out of only one, then it's very likely that the rotor inside the VP44 siezed.

dkenny

if it stops raining..
I going to try loosening all the injector lines at the back of the VP44..
but so far it sound the Vp44 died

thanks

-dkenny

jrs_dodge_diesel

No problem. Hope the weather clears up for you. Give this site a read, very comprehensive info on the VP44 and diagnosing it:

VP44 Diagnostic

dkenny

well maybe tomorrow..if the rain goes..

dkenny

well..then rain is gone..
at little cool this am to be working on my truck, but I did

removed 4/6 injectors lines at the back of the VP..cranked...

no fuel..sound likes its time for a new VP..the smart or other programmer
is going to have to wait...

-dkenny

Jay123

Let us know what happened Kenny

dkenny

replacement VP is on order..
I post an update after I get it installed..

Thanks

-dkenny

Jay123

Just saying that over the past few weeks of tests sometimes I got fuel to seep out at the cracked injectors, and sometimes not.
Once I used my buddies vacume pump hooked up before the injector pump, sucked for a min then I started to get fuel at all injectors again.
It just seemed to depend on randomness as to weather were gonna get past the big bleed back bubbles.
A few times I could clearly see that my new LP pump was completely unable to move fuel.
I put a 10 foot clear line were I only needed 2 foot. This gave me a big picture of all the random back siphoning and air trails as well as periods of giant air segments. Most wonderful of all it showed me after using the vacume pump anywhere before the vp that the big tank line was now full and ready to rock with no further bubbles in it again.