First new to site. I have another vp44 question (sorry). I replaced my vp44 back in oct 2011 and also added the raptor frrp pump and i made a big line from fuel filter to vp pump. both were purchased form thoroughbred diesel. At the time i was working out of town and wife was driving it when it did not restarting in the wendys drive through. so i had her tow it to a diesel shop to be looked at. them came back with needing a new vp44 pump. so i order the parts and installed them, got the truck running and drove it 20 miles or so. Got home it sat for 30min and went to start it and it took way longer then normal. So i thought the pump might be making to much pressure so i unplugged the cable to the raptor and the truck fired right up. plugged the cable back in and it hard starts. Crank pressure is 11-12. idle is 16-17 and wot 14-15. so i let the problem go as the truck manly sets and when I do drive it I let it run never turning it off, so today I drove it, turn it off and lets just say she got towed home will not restart. crank psi 12. Not sure but i think the vp44 has gone bad. have no codes. What do you guys think. Thanks for the help.

Did you unplug the pump and try to start it like you did before? Your pressures appear to be good. What kind of pressure gauge do you have, mechanical or electric?You could help us out by filling out your signature in the user cp so we know more about the your truck.

dripley, yes i have been playing around with it for last couple of hrs. I have a mechanical gauge. Its a 1999 stock other than the raptor frrp pump. i will update my signature

That is odd that the fuel pressures appear to be totally normal but the VP44 is behaving the way it is... The only thought is possibly a air leak?

How did you check it for codes? Key trick of scanner. An air leak is what caused my hard starting. Unpugging the pump and it starting is wierd with your pressures where they are. Do you have a test gauge to test against the one in the cab?

dripley, i used a snap on scanner. I put a test gauge on the fuel filter canister and both read about the same. Just came in from messing with it. tried bleeding the pump and injectors. Still will not start.

hmmm.... im stumped on this one. You positive you got the proper pump? they are different for auto or manual. also i would call them and get dialogue started so you wont have much time wasted if you do have to replace it again. I purchased mine from them also and have had zero problems. You may have gotten one that has a failed computer and its just not putting out a code?

There are two pumps so and ho. Ho came on the 6 speeds and so came on the 5 speeds and the autos. There is someother after market hot rod pumps but i dont know anything about them. Cummins is right about getting a dialogue with Thorobred going. you are probably going to need their help also.Did you get any fuel thru the lift pump or the injector pump?Where is your FP gauge connected?

CUMMINSDIESELPWRI have been in contact with Wade @thoroughbred he is the one that told me to disconnect the power to the pump to see if the truck would start. he also told me about that i could wire up the pump not to run at start up. but i feel that just a band aid for the bigger problem. they have been great so far. I plan on calling him back in the morning just to make sure i got he right pump. At this point i just want the dam thing to run. I have a feeling i got the wrong pump or one with a bad computer as it has been doing this from day one. Dripleymy gauge is on the the 90 elbow at the inlet port on the vp44. I got fuel to the pump and fuel to 1,3,4,5

look on the top of your pump, you will see lettering. also on the side behind the return line on the vp is the part number. check your invoice of the vp you got from TD and see if you got the right one.

http://www.thoroughbreddiesel.com/bosch/vp44-injector-pump.htm

Thoroughbred Diesel offers replacement Bosch Vp44 Fuel Injection Pumps that have been rebuilt by certified Bosch tech and have been tested on a test stand for 4hrs before the pump is sent to you. Bosch VP 44 diesel pumps are also upgraded with all the latest upgrades required by Bosch, such as a thicker diaphragm, and new computers. Our VP44 injection pumps come with a 1yr unlimited mileage warranty.

15x

470506027

470506022

470506015

407506011

470506005

17x

470506028

470506021

470506014

98.5-99.5 & 6 speed manual & automatic transmissions

99.5-02 24 Valve 5 speed manual & automatic transmissions

Part #VP4415X

99.5-02 6 speed manual transmissions

Part # VP4417X

Thoroughbred Diesel Hot Rod Pump

100hp over stock VP44 Injection Pump - fits 98-02 Dodge

Part # DG59VPEX-34

Industrial Injection Hot Rod VP44 100hp over stock - fits all models

Part # IIS0470506028SHO

98.5-02 Diesel 5.9 Cummins Dodge 2500/3500 Dragon Fire Extreme Vp44

.093 Connector Tubes & .093 Injection Lines Required

Part #IIS0-470-506-11

look on the top of your pump, you will see lettering. also on the side behind the return line on the vp is the part number. check your invoice of the vp you got from TD and see if you got the right one.

http://www.thoroughbreddiesel.com/bosch/vp44-injector-pump.htm

Thoroughbred Diesel offers replacement Bosch Vp44 Fuel Injection Pumps that have been rebuilt by certified Bosch tech and have been tested on a test stand for 4hrs before the pump is sent to you. Bosch VP 44 diesel pumps are also upgraded with all the latest upgrades required by Bosch, such as a thicker diaphragm, and new computers. Our VP44 injection pumps come with a 1yr unlimited mileage warranty.

15x

470506027

470506022

470506015

407506011

470506005

17x

470506028

470506021

470506014

98.5-99.5 & 6 speed manual & automatic transmissions

99.5-02 24 Valve 5 speed manual & automatic transmissions

Part #VP4415X

99.5-02 6 speed manual transmissions

Part # VP4417X

Thoroughbred Diesel Hot Rod Pump

100hp over stock VP44 Injection Pump - fits 98-02 Dodge

Part # DG59VPEX-34

Industrial Injection Hot Rod VP44 100hp over stock - fits all models

Part # IIS0470506028SHO

98.5-02 Diesel 5.9 Cummins Dodge 2500/3500 Dragon Fire Extreme Vp44

.093 Connector Tubes & .093 Injection Lines Required

Part #IIS0-470-506-11

If I am reading all of that right the HO pumps came on 99.5 - 02 6 speeds and apparently some differant versions of both HO and SO.

I don't know if this would be a problem but... the VP44 does not like fuel pressure when starting. The ECM runs the stock fuel pump a couple of seconds then shuts off until the engine starts. The VP44 has it's own built in fuel pump... if the lift pump runs ON with the key, the pressure tends to resist the starting flow. When I had my AirDog installed, I insisted on sacrificing the OEM pump (cut the wire off to make a pigtail) wire & used that as the trigger for the new Lift Pump to retain the ECM starting sequence. But it did run... however you have it installed... ??Russ

The ECM runs the pump during starting but only at 50% to reduce the pressure to the vp. That is part of what is baffling because yotehunter's appears to be doing that and it still want start. My pressure is around 10 to 12 psi during cranking and 19 after start.Mr. Hunter, I take it wont start with or without the pump connected now.

i got it running this afternoon. I took the big line off from the vp44 to the fuel canister and put the stock line back on. i also lowed the fuel pressure at the raptor to 14-15 psi. the truck started on the second crank. crank pressure was 12psi. i drove it for about 15 min around town wot drop to 10psi not sure but the stock line and the fuel filter might having something to do with that. got home turned it off and wait 20 min and went out and started it. It hard started but not as bad as it has been when hot. tomorrow i am going to drop the pressure down to 12 psi and see if the the hard starting goes away. if it does then I will look at my option of rewiring the pump not to run during start up and bump the pressure back towards 16psi. Not sure if my ecm is running the the pump @ 50% during start up or if I can have the truck re-flashed? Thank you all for the help and info.

Here is how to test cranking pressure...

I'm still a little baffled it wont start at 10 -12 psi, but it sounds like you are on the right track for trouble shooting. let us know what happens.

ill test mine and see what im running at. mine starts withing one turn of the starter and i run higher pressure than 10psi...thanks for the vid mike!

Mine starts so quick the only way i can ever see starting pressure is when repriming the vp.

That is odd that the fuel pressures appear to be totally normal but the VP44 is behaving the way it is... The only thought is possibly a air leak?

I'm with mopar on this one, mine did the same thing, had to basically bleed the lines every time i started it, i pulled everything apart today (i have the exact same set up, raptor with big line kit to filter housing) and after checking all the lines and coming up with nothing, i pulled the filter housing drain valve assembly apart, the two little washers that seal the drain valve to the filter housing were toast!! i also pulled the valve assembly apart and cleaned it up, it was stickin a little so i figured it may not be seating properly.....any way, its back together and fires up just fine now, no hard cranking, no bleeding the lines every time i want to go somewhere....just a thought