Engine/Transmission (1994 - 1998) What is normal fuel psi?? I want to get a FP Gauge,

[C. Harlan]

but dont know if I need to get one that tops off at 15 psi, or need a higher psi gauge... . BTW, which banjo bolt do you replace with the genos bolt? is there a specific bolt part # to use when ordering?? I really want a 3rd gauge, and will probably order it straight from ISSPRO, as to match my other gauges. I dont care for the way DiProcols look, and can't afford to swap out to all AUTOMETER's, so I figure I will just stay with the ones I have now, and get one more... Any tips or info would be appreciated!



-Chris-

 

[Joe G.]

Chris,



For your 12 valve you need a 40 PSI scale. That's because in certain situations you can hit 30 PSI or a little over. Normal pressure should be about 21 PSI at 2000 RPM with no load, ie. trans in neutral. It can vary quit a bit from that point. Depending on the situation you could see anything from 15 to 30 PSI. A 40 PSI scale is not normally offered so you would have to check with a vendor of the brand of gauge you want. I got one from Westach by asking about it.



The best place (thanks Bill) for a 12 valve is to tap the banjo fitting on the side of the injection pump instead of the fitting on the filter.

 

[illflem]

If you want it to last go with a mechcanical gauge. If you want it to match your ISSPRO gauges you might have to use a 40 psi boost gauge. It will work fine but will say boost on it.

 

[Bigsaint]

Do you guys need one with the 12v's mechanical pump ? Never see many complaints of them failing.



Scott W.

 

[illflem]

Scott, we don't really need a FP gauge like the 24s do but they're great for diagnosing problems and keeping track of filter plugging. All a 12 valver really needs is a temporary FP gauge for occasional testing.

 

[C. Harlan]

Scott, we don't really need a FP gauge like the 24s do but they're great for diagnosing problems and keeping track of filter plugging. All a 12 valver really needs is a temporary FP gauge for occasional testing.

... . But what if I buy a 3 gauge pod?? what do I do in the other times I am not using the gauge??? Just a thought to ponder...



-Chris-

 

[Joe G.]

I disagree. I think 12 valves DO need a fuel pressure gauge. It's the first thing that will let you know you have bad fuel that's plugging up your filter. In addition, I have rigged an idiot light on my fuel pressure that comes on if the pressure is below 10 PSI.

 

[Bigsaint]

Okay, thanks guys, that makes sense. Must be nice to only have to worry about bad fuel and/or a clogged filter, rather than a dying POS pump .



Scott W.

 

[C Schomer]

A couple yrs. ago I made a fitting to go in the air bleed on top of the filter. Did a temp. check - it hit around 30 psi. . I think I'll just check it yearly or if it get to running crummy - so far it hasn't. Craig

 

[FATCAT]

Pictures

Any pictures of the coupling in the banjo fitting to the fuel pump?

Or any surgery needed to the banjo fitting to put in a FP gauge sending unit.



Pictures, Pictures, pictures ... . please.

 

[illflem]

Sort of hard to get a good picture of one, all it is a banjo bolt with a hole drilled though the top and tapped to 1/8" pipe thread. Just remove the bolt and drill from the inside it will keep your bit straight, tap from the outside. If you can tap for a pyro this is a piece of cake. Geno's also sells them, even their picture isn't very good. Click here Never install a sender directly to the banjo bolt, vibration and pulsations will kill it in short order. You need to isolate the sender from the engine with a hose and use a gauge snubber to dampen the pulses. Even then there is no guarantee the sender will last, best bet is a mechanical gauge.

 

[FATCAT]

Banjo bolts

Illflem,

those bolts sold by Geno's are for '98. 5 and up modle years. Are you saying that they would also work for my '97 in the P7100 pump?



If so that would be great, otherwise I would probably just buy a new banjo bolt and drill that one instead of drilling my original ... you know, Murphy's Law always hits when working on a original anything with out a back up part.

 

[illflem]

Seems I recall 12 valvers saying they use them, best bet is to ask Geno's before ordering. Like I said, doing it yourself is easy. Having an extra is good too. Order washers with it also.



Banjo bolts are very common on hydraulic systems, most places that carry hydraulics will have them in stock, I've even bought them at Napa but never for a Cummins, have no idea what the size is.

 

[radixr]

Banjo Bolt

The Geno's tapped banjo bolt will not work on our 12-valves. Tap it the way illflem described.

 

[Deezul1]

My fuel pressure gauge let me know when the overflow valve was going bad which resulted in a loss of power but at least I knew what the trouble was so wasnt worried about what was wrong.

 

[EB]

What's causing this?

Since everyone is talking about fuel pressure, what would cause a filter to split and the new one to blow out the top gasket five days later. Split one was a Wix, the new one was an O'Rieleys (on the road repair) Last night on the way to Odessa, Tx is when the second one blew the gasket, (I got to get a relocation kit) Can't figure why it is doing this, and yes, I did get the old gasket off before I put the new filter on. Anyone got any ideas?

 

[illflem]

EB, sounds like your overflow valve is malfuntioning, sticking closed allowing too much pressure. Replace it. You could also have a kinked or melted return line.

No problem with the Wix FF, it is exactly the same filter as the Fleetguard.

 

[**ICEMAN**]

charlan,,i was reading your truck profile and was just curious what a "stupid pump" is ? and whats the "power edge box" being used for?

 

[C. Harlan]

Since my truck is a 98. 4, it is not controlled by electronics, thus by foot. . since there is no computer in there, it is a stupid pump... The Edge box, I won at a Diesel rally back in October... its like when a guy wins a free clutch to go in his automatic equipped truck... yeah, along those lines, hehehe... . The edge box is waiting to go into my next truck, though I do not plan on selling mine anytime soon. I will more than likely upgrade to a COMP box anyway.



-Chris-

 

[The patriot]

Originally posted by charlan

... . But what if I buy a 3 gauge pod?? what do I do in the other times I am not using the gauge??? Just a thought to ponder...



-Chris-

I have the 3 gauge pod.

Digital fuel press on top with a switch so I can check pre-and post filter readings, boost gauge next, and pyrometer on the bottom.

I REALLY wanted to get some mechanical gauges for the fuel pressure, but wanted them next to each other. The boost and EGT aint moving (I already had them there with the old two gauge pod) so unelss they make a 4 gauge pod, it will remain a digital electric gauge.

Eric



PS I havent pulled any real loads since putting the gauges on, but I've NEVER seen the press under 20 psi.

It runs between 23 and 31 in my truck.