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Scanned for codes and nothing showed up. We scanned with 2 different scanners to double check it. Nothing. O.K. guys checked fuel pressure and it has 10 psi. give it fuel and it drops like a lead weight. I DO believe we might have found the problem with help of all of you. Thankyou for all advice.

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Just now, farmboy said:

What is good fuel pressure for a Cummins 24 valve? I have 10 psi at idle but goes to nothing under load damn near. Thankyou in advance.

Yup there’s your problem. You need 18 22 psi at idle and 14 16 wide open throttle. I would get a Fass or Airdo fuel system as the stock on will just keep going out. It will be a surprise if you didn’t ruin your Vp44 yet. Replace lift pump and then see wht happens. 

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18 minutes ago, farmboy said:

What is good fuel pressure for a Cummins 24 valve? I have 10 psi at idle but goes to nothing under load damn near. Thankyou in advance.

 

Normal run span is 14 to 20 PSI. So like my truck idles at about 17-18 PSI and WOT might pull down to 15 PSI. This is a good fuel pressure. 

 

14 PSI to 20 PSI is a good fuel pressure.

 

10 PSI to 14 PSI is a marginal realm. It's still OK and meets even Dodge's specs but after the pressure drops below 14 PSI the overflow valve is closing till it reaches 10 PSI and its closed tight. Now there is no return flow from cooling and lubing purpose and the VP44 take a beating.

 

Below 10 PSI your causing damage to the VP44 for sure.

 

This is another reason why low-pressure lights are a bad idea being most all of them come on at 3 to 5 PSI which by then the damage is already being done. Think of the fuel pressure as being the oil pressure for your VP44. The only thing that lubes that pump is the fuel itself. 

Edited by Mopar1973Man
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Thankyou Mopar1973Man. I've followed some of your other topics and find you to be very good on these trucks. Thankyou for all you do and thankyou to everyone else also. Thanks Guys

I'll check in on a fass tomorrow. Thankyou 

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14 minutes ago, farmboy said:

I'll check in on a fass tomorrow. Thankyou 

 

I not sure of the purpose of your truck. You might consider both the AirDog and the FASS both. AirDog is a much smaller package and easier to tuck up and out of the way. FASS is the favorite for most here but the FASS is a much larger pump and difficult to protect the filters and pump from flying debris and strike damage if your running offroad for any reason. Something to consider in your choice...

 

There are few people here that went to the fully mechanical pump that is belt driven off the crank. Plenty of options and things to consider.

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While you are considering a new LP, during the install you ought to consider replacing the restrictive banjo bolts at the filter canister and going to the IP.  Many here have opted to use a larger diameter fuel supply line from the tank the LP and then to the IP.  That will also help you have stable fuel pressure under WOT.  Something to consider. 

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Most all fuel system today replace most if not all the stock fuel line and banjo bolts. Like FASS and AirDog I know for sure replace from the fuel tank to the injection pump. I would suggest to keep your stock fuel filter and get the big line kit from Vulcan Performance so you not deleting that stock filter. 

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O.K.i will do that. I experienced bad fuel lines collapsed on a semi that wouldn't run once. If this Dodge was a semi I would have had it figured out by now. I'm good at semis but nothing to brag about on this pickup. Thankyou for all your help greatly appreciated.

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9 hours ago, farmboy said:

I experienced bad fuel lines collapsed on a semi that wouldn't run once. If this Dodge was a semi I would have had it figured out by now.

 

Pretty simple to diagnose. Fuel pressure gauge and error codes. 

 

Fuel pressure should be between 14-20 PSI all the time while on the highway.

 

Error codes will tell you if there is any damage to the VP44 electronics or the timing piston. 

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