Jump to content

Archived

This topic is now archived and is closed to further replies.

Recommended Posts

Well I just had a bad day! While driving my truck passing someone up hill I lost all power so I coasted to the shoulder!:banghead: After checking for fuel at the injectors with #1 and #3 lines cracked loose and getting nothing I then went with the inlet line and broke it loose fuel sprayed everywhere! I called my buddy with his 2008 Chevy 1500 and with a tow strap we made it home!!!:banghead: Broke out the scanner and found a P0251 YIKES!!!:doh::banghead::doh: From what I found on this site that means I need a new VP44?!?!? :spend::shrug: Can someone please tell me I'm wrong??? If I'm not where is the best place to buy a new IP from? Thanks for the help in advance!

Share this post


Link to post
Share on other sites

i got my IP from thoroughbred diesel. they dont charge core up till a couple weeks of no core return. ensure you get the correct model too. auto tranny IP are a bit different than the manual tranny IP's.

Share this post


Link to post
Share on other sites

I have heard here and elsewhere you can run a SO on a HO, but not a HO on a SO.

Share this post


Link to post
Share on other sites

yeah thats what I thoughtplus the IP is the same for the manuals (5 speed) and auto right - no differenceonly the HO output is different

Share this post


Link to post
Share on other sites

I have heard here and elsewhere you can run a SO on a HO, but not a HO on a SO.

I heard that too but the results are mixed some say it works fine and other say it doesn't. Years ago I was saying the same then that I got slapped down for it... So I tend to say "Put back the right part if you want it to run right!" :thumbup2:

Share this post


Link to post
Share on other sites

I definately meant for that to be what i heard. I do not speak from experiance. When I replaced mine I installed a HO just like what came off of it. Thats my expirience.

Share this post


Link to post
Share on other sites

Here is a test procedure... DTC P0251: FUEL INJECTION PUMP MECHANICAL FAILURE FUEL VALVE FEEDBACK CIRCUIT Give that a shot and hopefully its simple fix... But typically its a VP44 failure...

Well I ran thru the diagnosis process and everything checks out good! Thanks Mopar for the dummy proof step by step destruction's!:thumbup2: It is a good thing to know that at least the electrical side is good, now I must save up the cash to order a new pump! Or p-pump??? Anyone on this site done this or have any experience with a 24v that's been p-pumped?

Share this post


Link to post
Share on other sites

P7100 is better for power and longevity... But it will cost you dearly to convert to it. There is a minor down side of the static timing in other words timing is fixed compared to VP44 with dynamic timing that varies with weather and road conditions. (I know I'll hear from ISX on this :lol:)You also got to remember all the little thing too like throttle linkage is not part of the kit. Also your injectors have to be re-popped to match the pressures of a P7100 which is lower if I'm not mistaken. Change the cam or pull rthe cam to change the gear case plus consider installing the mechanic lift pump or going with a AirDog for P7100. Lots and lots of things to spend money on and so much work has to go into conversion...I still say VP44 is still worth it.

Share this post


Link to post
Share on other sites

I dunno.Id definately look into the p-pump. Huge power and easy tuning.Dont think its that expensive to convert - but not 100% sure. I see complete kits on CF often for around $1500-$1900 minus the pump.Your core would fetch some money and so would any electronic programmers which would be useless.So you may be in it for $3000 - then get $1000 back on vp stuff ...... so $2000 all up instead of $1000 vp.just a thought I have in back of my head if my vp ever goes ......

Share this post


Link to post
Share on other sites

$1900.00 on a kit ,$1700.00 on a pump = 3600.00 plus miss and labor if you cant do it yourself . vp44 pump under a 1000.00. unless you got lots of cash the vp is the way to go for most who need there trucks for everyday trans for work ect. we do 2-3 converts a month here at the shop ,but it is for a very small group of guys looking to make the bigger numbers on the rollers or who are going pulling play toys . getting a 1000.00 for your old vp stuff i could use that phone number i got 30-35 cores here i would sell.

Share this post


Link to post
Share on other sites

There's a guy on CF who was interested in the VP44 I had as a core. His shop rebuilds them I think. Lemme see if I still have that PM.

Share this post


Link to post
Share on other sites

Don't have the note anymore, sorry. He wasn't offering much, but it was better than a poke in the eye with a stick. I did better selling it to a gambler in IN. I suspected it was good but had no way to test it. He paid me $250 and it made his truck run again. we both made out.

Share this post


Link to post
Share on other sites

Mine was more of a 24v swap than a p-pump swap. All the parts came off my 268k original 12v that sprung an oil-water leak somewhere in the block. Swapped the timing case, pump, lift pump, cam and some other bits onto a $440 24v in unknown condition with some crash damage out of a wrecked school bus. The stock cam swap was a mistake. Too little lift, it doesn't breathe well and runs hot for it. Stock untouched ISB 205 injectors in it. May do some RV275s at some point but I really have plenty of power already and I'm sure a Big Stick won't hurt it at all. I read that the pop pressure difference results in retarding the timing about 3*, I set the P7100 to a bit over 18* aiming for 15 effective. It starts in cold weather like it's timed at 18 though.

Share this post


Link to post
Share on other sites

so the stock 12v cam wasnt right? and I dont quite understand the timing just yet with a ppump? should the injectors be repopped? or just adjust timing accordingly like you did?

Share this post


Link to post
Share on other sites

No issues with just adjusting timing that I've read. 12v cam doesn't have enough lift to flow well. Run the stock 24v cam of you're keeping an electric lift pump, that'd be fine.

Share this post


Link to post
Share on other sites

so the stock 12v cam wasnt right? and I dont quite understand the timing just yet with a ppump? should the injectors be repopped? or just adjust timing accordingly like you did?

Yes you injectors have to be re-popped because of the lower pressure of the p-pump.

As for the p-pump where the gear is place on the pump shaft that is the timing its get all the way across the RPM span... As you see the pump shaft is nothing more that a camshaft.

Posted Image

Now on the VE pump and VP44 pump they have a adjustable cam ring that move forward and backward in time to allow for timing changes. The VP44 is fully electronically controlled from ECM sensors and feedback and the old 12V had a single sensor for controlling the advancement cam and the rest was mechanical.

But the P-pump its static fixed. So if the initial timing is 13* BTDC thats the timing for all the RPM span...

VP44...

post-2-138698182143_thumb.png

Vp44 has a very dynamic timing table that is adjusted through engine coolant temp, Intake temp, boost pressure, throttle, and engine load. Yes I know the VP44 stock table is rather weak for MPG's why most people plug in a chip of some sort and get instant timing upgrade.

Share this post


Link to post
Share on other sites



×