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Is vp ok?

hosanna64
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hosanna64

hosanna64

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I am new to diesels and just bought this 99 which ran when I went to pick it up. It started really slowly like the batteries were dying but still ran. I got it home and realized the crankshaft sensor wasn't even plugged in. This was the reason the batteries were not charging. I replaced sensor and started looking around and found alot of unplugged wires in the engine compartment. Tried to start and lift pump was not pumping just making noise. Replaced lp on side of block and got pressure to vp at banjo entry. cracked lines to injectors and there was only a little dribble from any of them. Still no start. My question is: is there a way to rig these trucks to run without controls and with a bad vp just to sell? Or is my vp still good and some other sensor is causing the vp not to work. Thanks for your time and the best resource for these trucks.

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Mopar1973Man

Mopar1973Man

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Welcome to the family Robert...

As for your VP44 issues it was most likely sold with a failed or failing lift pump and the VP44 was on its last leg which is common. If the fuel pressure was or is below 10 PSI its a automatic failure for the VP44. Lift pump is kind of like a oil pump for the VP44. If there isn't enough fuel pressure to get overflow valve to open (greater than 14 PSI) then the VP44 doesn't get enough lubrication or cooling from the fuel because there isn't enough flow back to the fuel tank.

So to get the second smoking gun I need you to check the error codes and report back the P numbers here. Then we'll sit down with the error code list and verify what is going on.

As for running the only thing the engine requires to run is...

[*]ECM (Engine Control Module - Driver side of the block)

[*]VP44 (Bosch VP44 Injection Pump)

[*]APPS (Accelerator Pedal Position Sensor)

[*]Crank and/or Cam Sensor(s)

The engine will run and drive without but a Check Engine light will be present.

[*]IAT (Intake Manifold Temperature)

[*]MAP (Manifold Absolute Pressure - If unhooked it will be in limp mode but still drivable)

[*]ECT (Engine Coolant Sensor - If unhooked it will be in limp mode but still drivable)

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hosanna64

hosanna64

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unfortunately I disconnected the batteries to charge them before reading any codes with scanner. Now that it won't start, I don't get any codes from obd port. You answered my question as to the vp though. My understanding is that it won't fire without sufficient high pressure from the vp to pop the injectors open. So that means to me the vp should be good just need to bleed it sufficiently. Is there any thing else I should do besides crack open the injector lines then use starter to prime until fuel comes out?

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Lone Watie

Lone Watie

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I bought one of these code readers a few years ago after I was naive and let Dodge scan and fix for the small fortune of $700. Never again. It saves a trip to auto zone to use their's and also erases the CEL. It just gives the codes, so you have to research the causes. Dodge charges something like $100 to scan, this thing was $50. There are cheaper scanners on amazon as well for less than $50. Don't know how well they work. Just read the reviews on them. I now have a scan gauge II which does the same thing and then some. Here's a couple links: http://www.amazon.com/Actron-CP9125-PocketScan-Code-Reader/dp/B0007LEG2K/ref=lp_15707381_1_16?ie=UTF8&qid=1369920107&sr=1-16 http://www.amazon.com/ScanGauge-Automotive-Computer-Customizable-Real-Time/dp/B000AAMY86/ref=sr_1_1?s=automotive&ie=UTF8&qid=1369920258&sr=1-1&keywords=scangauge+2

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Mopar1973Man

Mopar1973Man

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unfortunately I disconnected the batteries to charge them before reading any codes with scanner. Now that it won't start, I don't get any codes from obd port. You answered my question as to the vp though. My understanding is that it won't fire without sufficient high pressure from the vp to pop the injectors open. So that means to me the vp should be good just need to bleed it sufficiently. Is there any thing else I should do besides crack open the injector lines then use starter to prime until fuel comes out?

Disconnecting your batteries will not erase any codes. Once stored they will stay there until you clear them. Getting them read will help diagnose what is wrong.:smart:

Correct.

http-~~-//www.youtube.com/watch?v=fn7J8FQ8x5w

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hosanna64

hosanna64

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I think I have not communicated well so far. I own and have used a scan gauge for several years now. I scanned this truck after hooking the charged batts back up and found 0one codes. I assumed I had erased them by disconnecting the batteries. You know what assuming does though. LOL. My concern is focused on the vp and does anyone think it has to be ok because it ran and drove when I bought truck. Just looking for some opinions from more knowledgeable folks than myself. I do not mind replacing but why if it is good?

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Mopar1973Man

Mopar1973Man

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My concern is focused on the vp and does anyone think it has to be ok because it ran and drove when I bought truck.

That's what I'm trying to figure out. I need to know 2 things...

[*]Error codes

[*]Fuel pressure at idle and WOT

These 2 thing determine the state of the VP44 health.

Like say I've got a truck that was ran on minimum amount of oil pressure 30 PSI at 2K RPM. It may survive and in may not. So fuel pressure is important to know about to determine if the VP44 was cooled and lubricated properly.

Error codes tell if there is any current damage to the pump that the VP44 PSG or the ECM can see. If error codes are present then the VP44 is damage and will most likely require replacement.

Here is the 4 killer's of the VP44...

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/25-fuel-system/415-bosch-vp44-injection-pump-requirements

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diesel4life

diesel4life

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Make absolutely certain you have no leaks in the fuel line anywhere. A minor leak will introduce air into the system and cause hard/ no starts. How long are you cranking the engine with the injectors cracked loose? Which other sensors did you have to plug in? That is rather strange why they would be unplugged in the first place....

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hosanna64

hosanna64

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Make absolutely certain you have no leaks in the fuel line anywhere. A minor leak will introduce air into the system and cause hard/ no starts. How long are you cranking the engine with the injectors cracked loose? Which other sensors did you have to plug in? That is rather strange why they would be unplugged in the first place....Will check for leaks. I have only cranked about 30 seconds total because of the batts dying again. All of the other sensors seem to be plugged in but I do have some weatherpac connectors that aren't plugged into anything underhood. I will try to get pics and see If anyone knows what they were/are supposed to be plugged into. I also thought it strange so it made me wonder if they were hiding something just to sell as I got the truck for around 2000. :thumb1:

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hosanna64

hosanna64

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The batteries were low before I tried to start because of the lift pump not working properly. When I said 30 seconds, that was the time I tried after installing the new lift pump and bleeding up to the vp. They still may need to be changed out, but have a date of 2010 on them. I have 12.79 on each battery now so that should be sufficient to try a start. Thanks all.

- - - Updated - - -

Here are the post-12906-138698203618_thumb.jpgconnectors that I found disconnected

post-12906-138698203601_thumb.jpg

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hosanna64

hosanna64

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Thank you all for the replies. update: I replaced the vp and it didn't start. I have replaced the cam position sensor, crank pos. sensor, starter, and batteries. still no start. I read on blue chip to hot wire the vp. Did that and started right up and idled. Then hot wire got disconnected and died. So chasing down electrical demons. Narrowed it down to the pin 7 on vp plug gets 12v while key is in run but immediately drops to about 9.5v when in start. This is causing my starting problem. Also I can't seem to erase any of the codes stored. Would this indicate a bad ecm or something else? I have cleaned all grounds that I can find. Thanks again.

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