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Cranking is slowly increasing before start.


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I am on my 3rd fill up with 1oz of Super Tech 2cycle per gallon of fuel. Maybe coincidence! I use to bump the starter and engine immediately fired up. Now it takes 2-3 seconds of cranking. Stock transfer pump installed 36,000 miles now at 98,500 miles. Fuel pressures no load on truck: Idle 14psi, 75mph 10psi, on interstate WOT 8-9psi - this is monitored before the fuel filter. Fuel filter changed 94,000 miles FS19598 Fleetguard. Recent fill up 178 mile trip with 301 mile trip next day and there was a vacuum when removing OEM cap on tank. Even if I bump starter and pressure builds still 2-3 seconds of cranking. Any ideas :think:

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Fuel pressures no load on truck: Idle 14psi, 75mph 10psi, on interstate WOT 8-9psi - this is monitored before the fuel filter.

Ekkk! :stuned:

That's already a fail for the VP44... Pressure should be monitor AFTER the filter and should be 14-20 for optimal health of the VP44.

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/25-fuel-system/49-fuel-pressure-specification-for-bosch-vp44-injection-pumps

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

Recent fill up 178 mile trip with 301 mile trip next day and there was a vacuum when removing OEM cap on tank.

Check the tank vent. It might be plugged with dirt or dried mud.
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Ekkk! :stuned:

That's already a fail for the VP44... Pressure should be monitor AFTER the filter and should be 14-20 for optimal health of the VP44.

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/25-fuel-system/49-fuel-pressure-specification-for-bosch-vp44-injection-pumps

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

Check the tank vent. It might be plugged with dirt or dried mud.

In the video of the return flow, it seems at idle there is ~70% of return flow when compared to the engine OFF and the pump ON with pin hole flow. What is the reason for this as the input pressure was the same? Is it not true that when coasting downhill with the exhaust brake engaged/injectors closed there is ~70% flow returning and should be no heat in VP44 because you are at max input pressure.

In my setup, I wanted to see the actual pump input pressure and agree it is boarder line with the specs from the manual. I do have a Relocation kit (with new Carter pump) for the pump which eliminates the banjo fittings, but I have just started considering the FASS DDRP-02 direct Dodge replacement pump, but it does use the banjo fittings :doh:

Can you tell me where the tank vent is located?

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In the video of the return flow, it seems at idle there is ~70% of return flow when compared to the engine OFF and the pump ON with pin hole flow. What is the reason for this as the input pressure was the same? Is it not true that when coasting downhill with the exhaust brake engaged/injectors closed there is ~70% flow returning and should be no heat in VP44 because you are at max input pressure.

In my setup, I wanted to see the actual pump input pressure and agree it is boarder line with the specs from the manual. I do have a Relocation kit (with new Carter pump) for the pump which eliminates the banjo fittings, but I have just started considering the FASS DDRP-02 direct Dodge replacement pump, but it does use the banjo fittings :doh:

Can you tell me where the tank vent is located?

You should aim for 70% of return flow 100% of the time to aid in lubrication and cooling of the VP44. As for the shut down flow there was all this hype about creating a lift pump mod to cool the VP44 after running so the heat soak would kill the electronics. As you see in the video there is no flow and can't be done. As for using air flow it can't be done either because the electronics are mounted against the fuel side of the plate so the cover aluminum and the plastic case prevent air cooling from working. So fuel flow is key here. If you can keep 14-20 PSI that means instantly after starting the heat is remove from the electronics in a mere seconds.

That why the second link with requirements... The 4 things that can kill a VP44...

Maybe that's why my VP44 is heading for 200K miles and ZERO issues. (165K miles currently). :whistle:

Tank vent is located on the tank sender with a small plastic tube that comes out horizontally not vertical. (#6)

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I have an FRRP to be delivered today and work on installation this weekend. Since I have the relocation kit I will install it. Does anybody know what the connector out the tank is? Might as well replace tank to pump with the same fuel hose.

- - - Updated - - -

You will be proud of me Mopar1873Man :pray: - FRRP installed and set at 18psi. When the tank is empty, I will install the 3/8 fuel line from tank to filter and then find a 3/8 line from filter to VP44. For those who want to understand the installation

http-~~-//www.youtube.com/watch?v=Xbabxis78Rk

:thumb1:
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