2003 Fuel Pressures

[Greg Boardman-RIP]

With stage three injectors and a ttpm I had a bad stumble at 2800 rpms until I added the pusher pump Kieth sells.

 

[DBrundage]

Where can I get the banjo fittings for the 2003 to install a fuel gauge? Genos says theirs are for 2002 and not 2003. Is there a difference?

r/Donald

 

[Yo Hoot]

I think dumping the stock electric lift pump with a more durable one is the right way to go. I would like to see a setup that won't strand you if the electric pump fails. Some of the DMax guys put a bypass with a needle valve that acts as a "wastegate" to control pressure. Its plumbed to the return line.



Also some guys plumbed a bypass just for the sake of being able to get home in the event of a electric pump failure. The CP3 should be able to suck from the tank on it's own just like the DMax setup.

 

[bpenrod]

DBrundage,

I bought the Geno's 4/1 kit for my 2003 and ended up with one regular oversized banjo. I guess for the 2003 you need one tapped for the guage and 3 others, 1 on the bottom of the canister and two one the return line out of the pump. The one on top of the common rail is huge so I let is as is.

 

[bpenrod]

YoHoot,

I beleive the FASS has all those qualities!

 

[ThomasLawrence]

Where can I get the banjo fittings for the 2003 to install a fuel gauge?

Actually, I think the best solution now is the replacement fuel filter cover that Geno's now sells. It's a billet aluminum cap (replaces the plastic stock cap), with a 1/8"NPT port on top of it for a pressure sender.



It's not on their web page (that I could find), but I saw it in the catalog that came with the recent TDR.



-Tom

 

[AndyMan]

That sounds nice, but would you have to disconnect it every time you changed the fuel filter? I'd be afraid of leaks I think.



I've got the 02 banjo from Geno's. it would appear that it will fit. It seems like I've HEARD that it will. I'll let you know soon, I'm trying to ramp up to plumbing my gauge.

 

[bpenrod]

I was wondering that as well, I think I'll wait until I get my FASS BOMBed and then add it in, that way I would not have to remove it for filter changes.

 

[bpenrod]

Just looked at my pump and I forgot one Banjo fitting on the return output of the pump. So I used 1 tapped and 3 of the 4 regular banjo's from the Geno's 4/1 kit.

 

[Matt400]

Re: Additional Lift Pump Information

Originally posted by TDRadmin

As long as it is delivering positive pressure to the high-pressure fuel pump, the gear pump will take care of the rest.



The European version of the Cummins common rail engine does not have a lift pump. The gear pump takes care of delivering fuel -- as long as you don't loose prime.

I remembered reading that when the 03's hit the streets, thanks for posting it here Robin.



It must be then that the modified trucks are using enough fuel that the gear pump is seeing a restriction from the lift pump.



I would think for mild mods like 350hp, 1 psi you are borderline and 0 psi being the threshold of nearing a restriction it would be better to either upgrade the lift system of not have the pump there at all like the Euro model.



Rather than a permanent gauge to install, maybe a test port with transducer installed would be a better idea so you could use a more accurate digital multi meter for testing once you have achieved your hp level or for troubleshooting performance faults.



I like the idea of the filter housing cover with test port.

 

[bpenrod]

Found the fourth Banjo I had not swapped out last neigh, spent half an hour chasing the gfasket across the garage floor since it was the fitting on the back of the filter hosing. Also removed the lift pump to see if I can have a machine shop make and adapter.

 

[DLeno]

Originally posted by AndyMan

That sounds nice, but would you have to disconnect it every time you changed the fuel filter? I'd be afraid of leaks I think.

no. well, depends on what you mean. The Genos billet filter cap is fitted with a 1/8" npt on the dirty (lift pump) side of the filter, which of course is the center. The Westach electric fuel pressure sender screws into the new cap directly and the entire assembly (cap plus sender) can be removed as one unit with a 17 mm box end wrench. All you have to do is disconnect the electrical connections to the sender. seems like a pretty nice setup to me, but I've never been a fan of putting any liquids in the cab, isolated or not.



now then, the mechanical fuel pressure guys would have to either disconnect or build in extra fuel line length to twist during install/remove. not sure the latter is such a good idea.

 

[krabman]

Does this mean that someone has figured out how to make these suckers run without the lift pump? We tried for the better part of a day to get mine set up with a bypass in case of lift pump death and could not get the truck to run. These trucks do not have the same system as a Dmax or a euro cr and while there was much talk that the trucks aught to be able to limp without it during the release in real world tests afterword it turns out that the cp3 does need some help. And yes I do recall the early information out there saying the cp3 could work at zero pressure as long as there was flow. It would seem after the fact that the cp3 could work with zero pressure as long as there was a lift pump helping to provide that zero pressure with flow. There is a thread where I described what we tried to do in a prominent shop to set up a bypass and one of DC's techs even popped in and said the truck would not run without the lift pump. Now this doesnt mean that it cant be done but as far as I knew no one had done it yet. If this is doable does anyone know what was done to make it work?

 

[Yo Hoot]

The GMs do have larger diameter fuel lines.

 

[rbattelle]

Anyone know what the pressure drop across the stock filter is... 2 psi?



-Ryan

 

[BIG BOB]

Mine is hooked up the same as yours, 8--8. 5 idle, 7 at cruise, 6 at wot, empty or pulling a heavy load. I noticed the noise also. Let us know if it changes when you move it, or use a snubber. I have the di pricol guage with antifreeze in the line from banjo to sending unit. I didn't think this would transmit the noise like it does.

What setting was the Edge Juice on when this test was done?

 

[yogibear]

BB, that was so long ago I"m not sure, probably 2 or 3, thats what I usually pull at. On 5 it will go down to 1. Right now with Edge Juice on 2 or 3 it will not go below 5#. I hardly ever set the EJ on 5, if I do, only for a short distance. I've got 189K on her now, and no fuel problems yet. If I hadn't been laid up a month with pneumonia, it would be 200K+.



Larry

 

[gsbrockman]

I just had my fuel pressure gauge installed this evening and decided to do a search and reviewed many, many threads. On a cold engine, my fuel pressure was around 5 to 5. 5 psi at idle. After a 45 to 50 minute run at speeds between 60--70 mph, my gauge stayed near 5 psi, but on a hot engine, the idle was up to 7. 5 psi. My Fleetguard FS19579 fuel filter barely has 2100 miles on it, by the way. When I hit WOT, I can get 0 psi pretty fast, like with WOT from 70 to 90 mph on the interstate. All I have is an EDGE EZ on #4... I'd hate to see how quickly it goes to 0 psi at #6. When it goes to 0 psi, I've not noticed any seat-of-the-pants loss in performance. Since the last post, how many of you members have added pusher pumps, and what's the average price you're paying ?

Greg

 

[JStieger]

I just had my fuel pressure gauge installed this evening and decided to do a search and reviewed many, many threads. On a cold engine, my fuel pressure was around 5 to 5. 5 psi at idle. After a 45 to 50 minute run at speeds between 60--70 mph, my gauge stayed near 5 psi, but on a hot engine, the idle was up to 7. 5 psi. Greg

Greg-



I have low fuel pressures when cold too and it has been bugging me for a while! With or without my mods turned on the fuel pressure to the CP3 is always about 1-2 psi less than after running for about 30 miles or so. I thought it may have had something to do with the warm fuel being returned to the tank, but after a long run on a cold day I filled up 30 gallons of "cold fuel" and the fuel pressure never dropped. Maybe it takes a while for the lift pump to warm up? I have a pusher pump that is "work-in-progress" due to the crappy weather.