Fuel problem

[jrsavoie]

4 psi - not enough and why it cuts out. You are also killing the IP because there is not enough pressure for immersion lubrication.

Will L said how 8 psi is not enough because on acceleration it drops may be into vacuum

Nothing wrong with the IP yet, but get a real lift pump. That canister type barely put out 6 to 8 and die fast as to pressure even thought they still run.

I keep 15 to 18 psi regulated at the IP, and on hard acceleration it might drop to 10 with an old partially clogged filter

I use the Sure Cure Lift Pump Solution which is regulated

I am not going to speak to the wiring

Get a real lift pump capable of 15 psi and watch your problems go away.

See my posts at https://www.thetruckstop.us/forum/threads/down-on-power.52050/post-679517

Do you have links to what you recommend for a lift pump upgrade?

 

[royunion]

@jrsavoie I use the Sure Cure Lift Pump Solution which is an axial Dodge Ram pump 1999-2000 I believe adapted on both ends to plumb into the 6.5 without cutting any lines. You can Google the name or find it on eBay as a kit or partial kit

Been using it for 8 years, and when they get weak and begin to fail it takes 30 minutes to swap in a new one. When new they are tight sometimes so an automatic resetting breaker is used if they throw too much power and pop the breaker, and after a week maybe they settle down worn in and don't pop the breaker anymore. It is nice because if I am driving a new one or hit a bad pot hole which. Might throw the breaker I just Coast to to curb and shut off the key and restart it it because breaker has reset. I am on my third one since 2013 when I started using them.

 

[jrsavoie]

@jrsavoie I use the Sure Cure Lift Pump Solution which is an axial Dodge Ram pump 1999-2000 I believe adapted on both ends to plumb into the 6.5 without cutting any lines. You can Google the name or find it on eBay as a kit or partial kit

Been using it for 8 years, and when they get weak and begin to fail it takes 30 minutes to swap in a new one. When new they are tight sometimes so an automatic resetting breaker is used if they throw too much power and pop the breaker, and after a week maybe they settle down worn in and don't pop the breaker anymore. It is nice because if I am driving a new one or hit a bad pot hole which. Might throw the breaker I just Coast to to curb and shut off the key and restart it it because breaker has reset. I am on my third one since 2013 when I started using them.

So, not flow through on fail

 

[dbrannon79]

Here we go again..... just reminding everyone how deep it got here on this pump thing.

Opinions needed - Performed Optical Bump

Very good info, Thank you. I reached out to a couple of the local vendors to see if they can get one, if not it's online shopping for me lol. I also wanted to post an update to how things are going. so far I have noticed easier starting and haven't seen any more air in the clear return...

www.thetruckstop.us

 

[royunion]

@jrsavoie - You asked, I answered, and it works great.

You wrote "So, not flow through on fail" and while I do not know what that means - my lift pump never failed,, they just get real weak to produce pressure so I swapped them.

The last thing one wants is a DS4 trying to suck fuel when it cannot.

I am not going to call the 6.5 reliable, but the two things that cause the most problems I do not have to worry about.

While the DB2 does not need pressure to keep running and can suck fuel the DS4 does and without it the PMD blows transistors and fuel solenoids burn up. It is pretty simple.

But the 6.5 is now a dead engine family and people with later model OBD II models just need to know 5 psi is bare minimum + or - 1% test regulated pressure testing spec,, not what IP can actually operate the engine on and only a few lift pumps out there - certainly NOT - the OEM ones can properly provide enough pressure to run the engine.

People are welcome to tear up their engines swapping parts feverishly for that which is not the problem

It is simple, insufficient pump pressure cause insufficient immersion lubrication and eventually it all destroys itself slowly

 

[Will L.]

Flow on fail means if the lift pump FAILs, fuel can still FLOW through it because BOTH ds4 and db pumps can suck fuel from the tank through the lift pump.

Doing this is damaging to both of them. This is why I have promoted the use of a fuel pressure gauge since 1990.

Any pump can be bypassed by use of a couple T fittings and a one way check valve. But be aware cheap check valves fail often. The ones used in hmmwvs and hummers are excellent, but ya pay through the nose for them.
Also remember NEVER use any pure aluminum or any red metals (copper/ brass) in modern fuel systems because the alcohols used in the bio fuels has chemical reactions.

I am still of the same opinion:
Spend tiny money on something cheap and replace it often or buy quality and never worry again.

 

[jrsavoie]

I like flow through on fail just because I don't want to be dead in the water half a mile or farther from anywhere.

Anymore I can't wait without AC.

I might not be able to walk and help might be a while getting there

 

[Will L.]

I agree. Having an engine die while in the fast lane with tons of traffic is bad enough. Now do it with a rig where you loose power steering and power brakes.

Having an LP that doesn’t flow on fail REQUIRES a bypass/check valve set up imo.