Engine/Transmission (1998.5 - 2002) Getting ready to change LP, can I use old Banjos??

[DHarden]

I'm just getting ready to change out my LP after some low Fuel pressure reading. The only problem is that I forgot to get new banjo bolts at the cummins dealer yesterday and they are closed today. So, I was hoping someone could tell me if I can use the old banjo bolts at least until later next week when I can get new one. Thanks!





Derek

 

[DHarden]

Bump-just trying to figure out as soon as possible if I should get started with the lift pump. thanks

 

[Supermod56]

The gaskets might cause a problem, the banjos don't wear out. I used the old gaskets on my last lift pump install, no problem. I replaced them with the Geno's banjos a couple months later, never leaked. Just don't over-tighten!!!



Tom

 

[DHarden]

Thanks for the info Tom, I guess I'll get started then, one more thing, do you think NAPA would carry the gaskets and banjos?

 

[Supermod56]

Don't know, I doubt it. I got mine from Geno's. Got the whole kit from them, comes with all the stuff you need, plus the bigger banjo's won't hurt a bit!



Tom



2001 2500 4X4 Laramie SLT LB Quad 5-Spd. DD TTPM, DD Stage-1's, Bully Dog 4" Exhaust, AFE, JAKE Brake, Geno's Banjo's, 3 Autometer's on the A- Pillar, RASP/6-Speed soon!!!!

 

[Thomas]

Cummins Parts Locator"

 

[DHarden]

Just got the LP installed and there sure is a difference. I'm setting at 13psi @ idle but it doesn't drop below 11psi when i get on her. I went ahead and used the old washers and haven't had any leaks so far. Thanks for the help, God bless.





Derek

 

[mkhenry]

New LP

We just changed the LP on my son's 1998 and put in the larger banjo bolts from Genos. The old LP was 10 at idle and 6 at cruise. Scared to see what it was at WOT. The new lift pump reads 13. 5 at idle, 11 at cruise, and goes down to 9 when you floor it. Not sure if that covers WOT or if you have to get the rpms up to a certain amount.



Anyway, this is much better than the old pump, but is it good enough? Could we possibly have a tank screen obstruction also.



His truck is a bone stock 1998 4X4 auto with 3. 54 gears and only 61,000 miles.



Thanks

 

[mhenon]

Tank screen

MKHenry..... I've always had concerns with that tank screen. Not that it isn't a good filter or anything. . it's just that a guy can't take a peek at it once in awhile.

I don't know how to address the tank screen other then to fuel up at stations that sell a lot of fuel. If you start having pressure problems with your new pump... ... well... keep you eye on it.



Mike

 

[SEmerson]

I changed all my banjos out for AN fittings. It made a huge pressure differnce.

 

[MFranz]

Lift Pump Pressure

Derek,

what type of fuel pressure gauge are you using and where is it installed

in the engine. I recently installed a Westach electric fuel pressure gauge

and its installed after the fuel filter. My pressure readings have been 10 psi

at idle and around 7or 8 at 2000 RPM. I recently had a new lift pump installed

and the truck seems to be running fine. I got 17. 5 mpg at the last fillup.

To the point Im wondering if I can get better fuel pressure or if what I have is OK. Would more fuel pressure be of any benifit. Would like to hear your thoughts and anyone else that could share there experience.

Thanks Mike

 

[IMunro]

You don't say if you changed the filter or not. I have the Westach from geno's and the hose adapter to connect to the vp-44 schraeder connection. It was reading 14-15 at idle, 11-12 at cruise and the least was around 10 or so. I just installed a pusher pump at the tank and I get about 22 at idle, 18 or so at cruise. I haven't tried WOT. If it's been a while I would change the fuel filter. I feel that the truck has more oomph with the addition of the pusher-pump but without a dyno test who knows??



Ian

 

[SmokinJoe]

MKHenry..... I've always had concerns with that tank screen.

Why do we have a screen? It would seem that the fuel filter should tell us when the fuel is bad, not replacing a lift pump severla times till we drop the tank and remove/clean the screen...



What do they do on other industrial applications?

 

[ATClark]

Overflow valve or LP problem?

Just installed a fuel pressure gauge, and the idle pressure is 7 psi, running it falls down to 2 psi. How can you tell if the lift pump is the problem or the overfllow valve allowing the pressure to fall too low?

 

[Thomas]

Just installed a fuel pressure gauge, and the idle pressure is 7 psi, running it falls down to 2 psi. How can you tell if the lift pump is the problem or the overfllow valve allowing the pressure to fall too low?

I vote for the transfer (lift) pump. It's obvious that the system can hold 7 psi. How else can the drop to 2 psi be explained other than a tired transfer pump?

 

[ATClark]

Overflow valve function?

As I understand it, the overflow valve's job is to release fuel back to the fuel tank if the lift pump discharge pressure exceeds 14 psi (?). If the valve has failed, it might be allowing fuel to recyle back to the fuel tank at a much lower pressure, say 2 psi.



So the lift pump might not be able to deliver 14 psi, or the overflow valve may be 'opening' at too low a pressure, so even though the lift pump is working normally, it cannot ever achieve the desired dischange pressure.



Any ideas on how to tell which part has failed?

 

[Thomas]

... and the idle pressure is 7 psi...

If you're suggesting that the valve opens at 2 psi. how do you see 7 psi? Is it a "smart" valve that allows 7 psi sometimes and 2 psi at others?



Your symptoms suggest a dying transfer pump, symptons that have been posted MANY times on this board.

 

[ATClark]

Overflow valve might have failed (leaking by??)

If the overflow valve has failed (like partially open), then it cannot control the pressure at specification. At idle the lift pump can almost keep up, and so the pressure increases to 7 psi, then when the motor needs more fuel, it cannot deliver enough fuel (with the fueling leaking by AND going to the High pressure pump), and then the pressure falls to 2 psi.



Don't deny that many lift pumps have failed, just wanted to diagnose my problem before 'fixing it'. Don't want to change out the wrong part.