Engine/Transmission (1998.5 - 2002) new vp44 still hard start when warm

[gottorq33]

jus thad my vp44 slid in under warranty for replacement (gotta love having friend at dodge) anyway I was getting 0295 codes etc so vp had to be replaced. But now after I drive truck for a while and shut off and restart while truck is still warm it cranks for a few seconds before it will start what could this be (would my injectors do this or is it air in lines I am lost and have tried everything am ready to give up and take a lighter to it since it got hit on passengers side and while it was sitting I started to swap some stuff it has went to hell but the vp44 was just done yesterday help

 

[Joe Mc]

Sorry to hear you got hit. Glad that you got the VP under warranty. I'd go back to the dealer and claim it never did this before and let them figure it out - we pay enough for these things that they should do a bit of free work every now and then. At least free to us anyway the warranty company pays them for the work. I'm not Tech. but will give MHO - sounds like air is getting into the system somewhere and the pump is loosing prime? Of course the demon in this is locating the "somewhere". I'm sure some other members more fluent will ring in with other ideas.



Good luck - don't strike the match yet the good ol' TDR will help figure it out or at least provide support until you do. Keep us posted.

 

[gottorq33]

the tech is my friend which is how it got replaced how can I check for air or what else could it be am I hurting vp starting it in mean time

 

[keimmmo]

I notice in your signature you have a pusher pump. If you have over 7 psi fuel pressure when starting the vehicle, it could be the problem. Been there, had the problem. Oddly, not all trucks give trouble with too much pressure at start... seems to me not all VP-44s are created equal.



Steve

 

[gottorq33]

but it never did it till I put in mach5's and i THOUGHT MAYBE IT WAS because vp44 was dying but even after fix it still does what should I look at air in line,return line,lift pump was good when they did pressure test before vp44 replacement

 

[ToolManTimTaylor]

Originally posted by keimmmo

I notice in your signature you have a pusher pump. If you have over 7 psi fuel pressure when starting the vehicle,Steve

Yep I was going to say the exact same thing. Sure it prolly did not do it before but those mach 5's may have a different pop off pressure (all be it lower OR higher) and that will effect the way the VP sees fueling proceedure. And with a pusher setup it may be reacting differently that with the injectors you had before. OR one pump in the pusher setup is D>O>A and you would not know it because one is either pushing fuel thru the other OR one is Pulling fuel thru the other .



You have a ton of stuff and it never did it before the mach's went in ... . soo I would say that you allready have a part of the equasion. Swap em for stockers or a buddy's DDIII's and go for a rip and then try the startup proceedures and see what gives.

 

[gottorq33]

Okay just went out to truck after sitting all night fuel gauge needle shows 19psi turn key to on gauge falls to 0 turn engine over and fuelpressure looks like about 7 as it cranks and cranks for about 3 to 5 seconds before it starts then pressure reads about 16 or 17 for a minute then goes up to 19,20 and stays there it never used to have a problem when it was cold Iam getting ready to lose it if it was the pusher pump going bad it would act as a block correct? and if it was the lift pump pressure would be low right ? I have an autometer electric fuel gauge between fuel filter and vp44 I get 19 to 20 at idle about 14 cruise and about 9 WOT what should my gauge say when I go out to truck and turn to on position before I crank it over

 

[gottorq33]

come on guys need some help here

 

[ToolManTimTaylor]

does it run rough? I broke an injector and it took 5 or so secconds to start it but it would run o. k ish until it cracked then it just plain smoked like a puller.

 

[gottorq33]

it runs great once it starts could it be air causing problem

 

[KennyM]

If you have a possible leak in the fuel line feeding the vp44, you should see some fuel. Prime the pumps without starting and see if you have any fuel leaking. if you build up pressure without running the VP-44 the fuel should go the path of least resistance.



I would be suspect though that you have a leak between your VP-44 and the injectors.



Do you still have your old injectors? I know you went through hell with these Mach V's, but maybe you still have a leak. All it takes is a small scratch. Try and put your old injectors in, if you don't have any PM me. I still have the set from my 99.

 

[Lockard]

I have same problem

Please post updates if you find a solution. I am currently suffering from the same problem. I installed injectors (275's) and a lift pump six weeks ago. Even though I thought I primed the system well, it took FOREVER to turn over. To the point that I ran the batteries down trying to start it. I had assumed that I damaged the vp44 internals during all that cranking. The truck starts almost right off when cold but takes 4-5 seconds when warm. The truck runs ok once started but seems to have a slight power problem a smokes a lot more than it used to under WOT. No codes set. I have a vp44 ready to go in this weekend. With 130K on the truck it's probably time for a new vp44 anyway but just want to make sure that I don't do all that work and have it hard to start still. Thanks

 

[kbond]

Originally posted by gottorq33

jus thad my vp44 slid in under warranty for replacement (gotta love having friend at dodge) anyway I was getting 0295 codes etc so vp had to be replaced. But now after I drive truck for a while and shut off and restart while truck is still warm it cranks for a few seconds before it will start what could this be (would my injectors do this or is it air in lines I am lost and have tried everything am ready to give up and take a lighter to it since it got hit on passengers side and while it was sitting I started to swap some stuff it has went to hell but the vp44 was just done yesterday help

I think I have your anwser!! 2 times this has happend to me on my 01 and each time was the same issue. Air leaks!! Do a pressure test from the turbo side and I'd be willing to bet you find an air leak somewhere around the intake manifold plate or the intake horn. I would only notice hard starts after it had been run and warmed up. keep us posted.



-Ken

 

[gottorq33]

confused cause it was doing it when it was warm now it did it overnite when it sat overnite in dealer and I picked up it was fine went home next day started up and it cranked for about 5 seconds went out then came home went to move truck and it did same thing when hot

 

[kbond]

Originally posted by gottorq33

confused cause it was doing it when it was warm now it did it overnite when it sat overnite in dealer and I picked up it was fine went home next day started up and it cranked for about 5 seconds went out then came home went to move truck and it did same thing when hot

run a boost test and I bet you find a leak. Hopefully it will just be a gasket.

 

[ToolManTimTaylor]

Originally posted by KennyM



Do you still have your old injectors? Try and put your old injectors in, if you don't have any PM me. I still have the set from my 99.

Originally posted by ToolManTimTaylor

Swap em for stockers or a buddy's DDIII's and go for a rip and then try the startup proceedures and see what gives.

Stil sticking to an injector swap. Check fuel filter canister lid , and lines leading INTO the vp44 as AFTER is all under BIG pressures (20K+) and will show a leak. also check the fuel tank by opening the cap after shutdown to see if it sucks in air. If so then I would look at the tank vent being clogged causing a vaccuum restriction.



How is that lift pusher setup ... both running according to plan (In another words one pump NOT weaker than the other or possibly dead causing a HUGE restriction?)





A boost leak at startup has nil or no effect. At idle the VP44 gives only enough fuel to maintain an 800 no load rpm level. A boost leak will however come into play once building above 5 lbs and compounds performance loss as it climbs.

 

[kbond]

Originally posted by ToolManTimTaylor

Stil sticking to an injector swap. Check fuel filter canister lid , and lines leading INTO the vp44 as AFTER is all under BIG pressures (20K+) and will show a leak. also check the fuel tank by opening the cap after shutdown to see if it sucks in air. If so then I would look at the tank vent being clogged causing a vaccuum restriction.



How is that lift pusher setup ... both running according to plan (In another words one pump NOT weaker than the other or possibly dead causing a HUGE restriction?)





A boost leak at startup has nil or no effect. At idle the VP44 gives only enough fuel to maintain an 800 no load rpm level. A boost leak will however come into play once building above 5 lbs and compounds performance loss as it climbs.

I stated this wrong. What I call a boost leak is when I did a pressure test, I found the leak by the manifold plate (boost leak). Resnugged the plate bolts and ran another boost test. No leak and no longer had the long starts. This has happen to me on two occasions. The second time was 3 weeks ago. Started getting longer then normal startup times. I ran a boost test and sure enough it was coming from the manifold plate gasket. This time I had to replace the gasket. Ugly job. Anyway, after it was replaced, I ran another boost test and found that leak was gone but I also have an Intercooler leak. Not real bad but still leaks. My opinion on the hard start is air was being sucked vacuum style when starting creating the longer starts. A boost test takes 10 mins and is far simpler of a task the changing out injectors. Would suck to change out injectors and then still have the longer starts. If you had a bad injector or injectors, you would know through other signs once the truck started.

 

[gottorq33]

I have the dd big line kit that has a barb fitting from the vp44 to fuel filter and I noticed 2 things 1 thata line rubbed against powersteering pump fill cap lid and has worn hose down (not sure if that would cause air ) and second that the hose on the barb fitting feels like it has lossened up on the fitting and air may be seeping in where can I get another piece of that hose at start there and do a pressure test or a boost test next???? also which is the intake gasket you are refering to thanks

 

[KennyM]

I think it is the square gasket under the intake. When you do the injectors its good to have a new one in case it rips. If those braided lines are leaking, I think when you prime those pumps with out starting you should see diesel spraying out. I,m still not sure I understand the theory on why a leak downstream the turbo would cause hard starting. I only see a leak letting in unfiltered air with no boost, and loosing air pressure under boost. But twice this fixed hard starting.



Also if just one injector was leaking just a bit, wouldn't the engine still possibly fire just fine? As long as the other 5 are good. After thinking about it I do not think you have a leaking injector



For t-shooting this your going to have to pick a starting point. Either try different injectors to rule out pump. TMTT suggestions are great. try to bypass one of the pumps(lift or pusher). See if problem goes away. Let say your pumps are putting out the same pressure. Are your fuel lines the same size all the way through?

 

[gottorq33]

when we put the intake gasket back it was torn I just put some sealer on it and went also it first tore when I put the mach 5's in and that is when the problem started but it was only when warm now its when cold to I guess I should replace those 2 gaskets but could that really make a difference I cant believe that also when the did the flow test before vp replacement the volume test was within spec I dodnt know if they tested pumps by themselves next would be to check #2 INJECTOR connector tube because of the issue I had pushing in injector but I really cant see that I messed up a tube and this is only a sometimes starting issue