ado2b1

I've looked at alot of the posts on fuel pressure gauges and installs, but nothing answered my questions. Currently, I have a completely stock truck, I have a boost gauge installed, and have fp and pyro waiting on the seat. The fuel pressure gauge I have is Autometer Ultra-light 0-15 psi. Autometer says it "could" blow out if there was sustained pressure of 17 - 20 psi.

1) Has anyone installed the 15psi gauge and had any problems with the typical pressures seen on these trucks? I went with the 15, as the only other mechanical option is 100 (way to inaccurate), and the electricals are +/-$250, so not getting one of those.

2) Would my stock truck (105k) typically produce fuel pressure above the range of the gauge?

3) Is there any reason I couldn't tap into the "test potts"(?) on top of the fuel filter/water separator, rather than drilling and tapping a banjo bolt, or is it just bad practice to do it that way? BTW, I am installing a needle valve to eliminate some of the spiking I've read about, and just in case.

4) Finally, if the answer to the first question is yes, I will blow it out; could I put a bypass valve and tap into the return line (still way cheaper than an electric sender/gauge)?

Since it will also be somewhat fuel related, I am installing a banks ottomind. Will this drop my fp at idle, or just when "using" the box? Thanks for any answers/advice upfront. I haven't posted much, but I've used the forum to answer a LOT of questions.

coachgrowl

My truck has a carter lp. Idle is 14 psi and 10 at WOT. I think you will be at the limit of the gauge but it seems to me you will be ok.

Dinner

I would think you would be good. I havn't heard of many stock LP's pushing past 15. I taped my FP into the top of the Fuel Filter canister as well. The tap closest to the engine is post filter I believe, and the one to the right is pre filter...but im not 100% sure. Mine is on the tap closest to the engine.

Harbor Diesel

If you would like my 2 cents, I bought a tapped banjo bolt on ebay with larger fuel inlet ports and it goes in place of the schrader valve banjo bolt at the injector pump. You simply remove the old bolt and replace with the new one, then the pressure gauge line is attached with some additional plumbing hardware into the end of the new banjo bolt. You could also insert the needle or ball valve here as well to act as a snubber and to shut off the fuel in the event of a gauge or line failure, if you are not using an isolator. Just rember to install new washers on both sides of the fuel line. As for the pressure, I have a new stock cummins LP and get 12-13 psi idling and about 9 psi WOT. The pressure does go to about 15 psi momentarily when you first turn the key to "run" position before actually cranking over the engine, but no higher. My gauge goes 0-16 psi. Good Luck

ado2b1

I got the FP gauge in, started up and its only idling at 10.3psi, took it out to the highway went from a dead stop until 85 or so. At the upper range of second, the pump pulled down to 4.75 psi momentarily just before shifting, then remained a constant 5.5psi for the rest of the trip. Just driving down the road its getting about 8 or so depending on the position of my foot.

Does this mean its time to start looking into a new pump? Am I OK for the remainder of the summer (just a couple of months)? I really don't get into it much at all, but that might possibly change with the addition of the ottomind.

Here is another link I started asking about using racing (gas/alcohol) pumps:

https://www.dieseltruckresource.com/...d.php?t=158855

I think I could do this rather simply, I've plumbed plenty of gas systems. Are there any electronic/computer type controls on the fuel pump or is just a 12V switched source, with the initial pump prime taken care of by relays?

BTW, I went with a 90deg. needle valve on the test pott closest to the engine, came out with 1/4" 170 psi tubing all the way into the gauge. The fittings are compression-type with flared sleeves (?) not quite pipe, flared, or compression. No leak so far (+/- .5 hours). But I think it should be fine.

coachgrowl

JMO I think your LP is going bad. Relocate to the frame rail with whatever and you will save your IP.