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Hard Starting after Fuel pump Replacement


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Hello again all so thought i'd toss this out there to get an idea of what the problem may be on our Work truck. So about 6 month's ago When my boss got his replacement truck. a 1998.5 Dodge 3500 Auto,4x4, 24 Val Truck. I went through it (When i could he bought it sight unseen for way more then worth with rust out the butt and not worth the price tag IMHO) But, I replaced every Fluid, Filter, Power steering pump, half the front end (Owners wife said it "like to wander" spent a few thousand replaced every part in the front end no help at all.) But after i Replaced the Fuel Filter, Refilled the canister as all way's with fresh diesel. .....The factory Fuel pump went dead... So after a lot of argeement's about what part went bad(He say's a fuel pump can't just "Go Bad All of a sudden" *Note truck had 200k on factory fuel pump but, he said a stock pump is just as good as a airdog or a Fass<What i strongly fought for but, we went with the $100 autozone pump...After we got it all in and took forever to prime.. i mean over 8 hours..yes 8 a whole work day to get it primed and running. But even now after it sit's for a few hour's you have to pump the pedal while cranking to get it to start up then it runs great and will start and stop unless as stated it sit's for a few hour's. I told him it's bleeding off preesure some where but i've checked every bolt, nut, screw, tap, hose, injector's at least a dozen time's even one's i never touched. Still lt leak's off any idea's cause i'm out of them nothin seem's stripped or broke/Wore out that i can tell but what do y'all think it may be. Thank's for any help

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Whats fuel pressure?

Leave the fuel cap loose and see if hard starts stops.

Im guessing the injection pump is shot from the stock one going out. When you changed the fuel filter you broke the vacuum in the system. Most likely the stock pump was already gone and the injection pump was sucking fuel until the seal was broke

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I've lost prime or had tank drainback because of improper filter cap torque, but then I'm not sure if the 98.5's are the same plastic cap type filter as my 02. It's supposed to be turned to 25 ft. lbs.

Another drainback was caused by a loose injector after priming engine.

I think there is something wrong in the tank because priming should be a 5 min. job. You could have clogged screens in the tank from varnish, perhaps an old dealer installed intank lift pump and just may solve your current problem.

At any rate you need to install a fuel pressure gauge and have no more headaches with factory fuel lines and banjos. It's like trying to drink a coke thru a WD-40 straw. It's bad/ hard on the injection pump because it needs good easy fuel flow for cooling. It needs a min. 14 p.s.i. at all times for best cooling of the electronics.

A factory pump with replaced 1/2 inch fuel lines including the 1/2'' drawstraw will only attain about 14-15 p.s.i.. Aftermarket lift pumps are adjustable and can adjust higher for heavy hauling uphills when the cooling is most needed. However aftermarket pumps unfortunately are cutting back on quality and are loosing what used to be a pretty good reputation.

You should do these inexpensive items above before anything expensive..... you'll end up in the future doing them anyhow to protect the injection pump.

A little better option is with the lift pump moved down on the frame as close to the tank as poss. as these pumps are designed to push fuel rather than suck. Better to have around 30 micron pre lift pump filter to protect the lift pump. Filter should be designed for suction side.

MoparTechnition has a good suggestion above. He wants you to just bump the starter motor, not start the truck in order to get the lift pump going for the 25 seconds to see if the filter housing will fill up.

Edited by JAG1
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Ditto on the start bump w/o turning over, fuel pump should run for several seconds to build pressure & then stop.  My suspicion would be a leak...  air leak on suction side??  Rusty lines?  Also possible to have leaks on pressure side of lift pump.  A temporary test fuel pressure gauge would be a help I think. 

I wouldn't be surprised if the VP44 is toast after a lift pump failure.  Codes?

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Thanks for the info all sorry to take so long to respond and i will see if i can find a gauge to check the pressure. I'm trying to get him to let me install a fuel pressure gauge in the cab like i got but he "don't see a need for extra gauge's the factory ones are more then enough" for him on a work truck.... but, yeah I agree compelety that the injector pump is long gone and it lost it's pressure when i broke the seal on the filter housing that is why it took forever to reprime it and it's not holding pressure aswell over an extended amount of time. but it took a day to convience him it was the fuel pump and to drop the $100 on a cheap-o let alone a new injector pump guess i'll just have to let it go bad and ruin the motor and say i told ya so can't make him fix it ... Thanks again all will keep y'all updated.... 

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Fighting a up hill battle... I've got the same problem locally here. Everyone does the same thing and ask for the problem to be fixed but I suggest a better lift pump and a fuel pressure gauge and you get "Hua!?!?"... Truck ran this long without all that. Yeah you might get lucky now but wait till your luck runs out and eating VP44 for lunch on a monthly basis. Then most owner just sell the truck.

 

But yes I would suggest again the fuel pressure gauge.

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Should be more donar trucks out there for my stick shift swap then. But I don't see any cheapo's out there. These trucks keep going up in value. Seeing 2nd gen trucks selling for $20k+.

You can  blame  THIS  site!!!     If  everyone  who owned  a  Ram,  and   was a member here,   there  would  be   hardly any  trucks for sale...

(no reason to sell)

 

Hey Mike,     I should  change my name  to  BROWN NOSE BOB

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I was thinking of selling mine too, the guy at Unlimited Diesel Performance told me how much more my truck would be w a 6 speed, so guess what? Just waiting on a price for a 13" clutch.

 

Here all along I thought B n B was Bed N Breakfast.

Dave

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