Hard Start unless factory lift pump disconnected

[Jake]

I’ve searched quite a bit for info on this subject. 

But it always seems to pertain to trucks with after market lift pumps. My truck still has the stock lift pump. Are these hard starts still a VP issue? Truck runs just fine. For now I’ve installed a toggle switch off the ground wire of the stock pump. As long as the pump isn’t running starts right up I’ve yet to install a fuel pressure gauge which I know is a must. Was also looking for suggestions on a good one and wear to hook it up

[Mopar1973Man]

Too high of cranking pressure. 7 to 12 PSI is normal for starting.

[Jake]

Is that normal for a stock pump to overpressure during crank? Still a little difficult to start if it’s allowed to heat soak for 10-15 minutes. Also believe the starter could be weak. Brand new batteries and still cranks kinda sluggish 

[Dieselfuture]

So more then likely ecm is not reducing pressure for starting purpose. You really need to get it off the ecm and on relay, ecm will trigger relay. Then do delay relay mod also to eliminate hard start. So you'll add 2 relays to accomplish this. I'm not sure where that right up is, but someone will post it momentarily, I hope....

[Mopar1973Man]

5 minutes ago, Jake said:

Is that normal for a stock pump to overpressure during crank? Still a little difficult to start if it’s allowed to heat soak for 10-15 minutes. Also believe the starter could be weak. Brand new batteries and still cranks kinda sluggish 

 

No. ECM does a 50% duty cycle pulsing the power on and off. Heat soak is not an issue a long as you never see P0168 the the VP44 is overheated. Sounds like batteries, cables and/or starter is worn out.

[Jake]

That’s very possible. 17 years and 300k miles is a lot of cranking. Only code is the p0500 (I believe) which is wheel sensor related. A non VP44 issue would be a relief. 

[skyhigh4by]

I was having the same issue. Once warm it wouldn’t start unless factory lift pump was disconnected. New VP solved that. Now I have a FASS on a relay but no delay and it starts up after one revolution at 15ish psi. I did the same thing wiring the pump up to a switch. 

[adamey1000]

I had a similar hard start issue. mine was a weak starter. i replaced all of the battery cables for good measure, but probably not 100% necessary. You will be amazed at how slow your starter is turning right now. You wont notice the difference until you get a new one on there. And don't let the parts store kid tell you your starter is fine because it engages and spins. its just spinning too slow.

[Dieselfuture]

All it took for mine is a contact and plunger kidt, starts after half a crank. 

[adamey1000]

Just now, Dieselfuture said:

All it took for mine is a contact and plunger kidt, starts after half a crank. 

I did the oversized contacts and the plunger, but it still spun slow. I moved those over to the new starter before I installed it. 

[Mopar1973Man]

4 hours ago, adamey1000 said:

I did the oversized contacts and the plunger, but it still spun slow.

 

I bet money the armature brushes are too short (at least 1 is not making contact).I've got an OEM starter here with that exact problem. 

[Jake]

UPDATE. I replaced the factory Denso. Starter with a made in China amazon replacement (I know I know) and it fired up almost immediately. Before I get grief for the amazon starter. I have an abundance of amazon gift cards I get as travel reward points. So it was free and I still have the factory Denso to rebuild at my convenience thanks so much everyone for your help. So relieved it wasn’t the VP44

I didn’t realize just how slow mine was cranking until I heard another 2nd gen start up at the gas station. Several people told me personally it was the starter. I blamed the vp44 after my whole two days of research. I became a Cummins expert in record time ?

Edited September 15, 2018 by Jake

[Chris O.]

 

49 minutes ago, Jake said:

still have the factory Denso to rebuild at my convenience

Time for http://www.fostertruck.com/dodge/starters/rebuild-kits.html

I was @350000 miles when I did it, excellent rebuild kit

[Jake]

40 minutes ago, Chris O. said:

 

Time for http://www.fostertruck.com/dodge/starters/rebuild-kits.html

I was @350000 miles when I did it, excellent rebuild kit

 Yeah that’s the plan. Just couldn’t afford for the truck be down while I attempted to rebuild my first ever starter lol The Amazon starter seems to crank really fast. But I know deep down the durability is gonna be no where near the factory unit which was giving it everything it had left at 302k. New starter  Already makes a weird noise every so often ?. 

[Mopar1973Man]

6 hours ago, Jake said:

Just couldn’t afford for the truck be down while I attempted to rebuild my first ever starter lol 

 

Not hard to rebuilt maybe take you an hour to rebuild a starter. Slow starting typically is the brush plate so make sure to order that in the kit. I've got my OEM starter sitting in box for later to be rebuilt. Right now the blown head gasket is more important.