Adding a fuel-pressure check port

You could install the valve like you mention. They make solid track/band worm clamps for the higher pressure lines something like the ones with the slots for threads.

I don't really see the need though. Usually when a Jeep fuel pump up and quits, it up and quits. Unless you are having issues???

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > I occasionally want to measure fuel pressure on my Jeep WJ 2004 4.0L

What's a band worm clamp ? Is that what we call a Jubillee clip over here ?

Dave Milne, Scotland

The normal 'hose clamps' that screw along a slotted track are called worm clamps. They make them for higher pressure applications with a solid band stamped with threads.

I either use one of those or I double the old style ones.

Mike

Dave Milne wrote:

Rather than creating a potential leak problem, you'd be better off buying or making an adapter you could insert between the line and the rail to check pressure. You don't need a permanent test port.

Here is the connector at the fuel rail:

Is there an adapter available?

I do not have any problems; I was thinking of putting in a fuel port as a pro-active measure. I would like to study the pressure patterns at idle, during winter, while accelerating and such, so that when a problem occurs, I am somewhat prepared. The problem could be fuel pump, fuel regulator, leaks and such. Moreover, when the car stalls, the problem could or could not be fuel pressure related.

My last car, a 1994 Ford Taurus, was running pretty good until 198K miles when it stalled on the road, in 2004. I thought the car is old and would not be worth towing and taking to a mechanic. The car did eventually start but did not have power. I replaced it with my current Jeep. I wish I had studied it's fuel and intake systems; I get a feeling there was a relatively minor problem.

Only as part of a fuel pressure test kit. The problem is getting the fiddly metal bit that is on the rail.

I'd probably just splice in a test port with a spare hole for any future pressure gauge. My only concern would be putting excess weight on the quick connector. I've got a setup that does just that and if I'm not careful about the excess weight it can cause a drip in the wintertime. However, I've got a bit more connected to the rail than you would. :)

's a 75 psi regulator by the way.

Ok.. this is what your going to see.

ign on -- idealy a few psi from the last shutdown followed by a run up to operating psi start/idle -- basic static pressure running -- basic static pressure wide open -- a couple more psi (depends on the year) shutdown -- a slow but steady build as fuel in the rail expands due to heat. Followed by a return to normal and a very slow decrease

Nothing apart from a very sensitive electronic sensor and scope could detect injector firing.

About the only things of interest are

1) lower fuel pressure on acceleration - clogged fuel filter - bad pressure regulator (which for your model is in the pump) - worn pump 2) slow decrease in pressure with engine off - leaking fuel system or injector

Your probably better off buying a good scantool and learning how to use it. Most of the stuff is monitored by the compooter these days.

Yea.. they ditched the check port sometime in 05 I think.

Have a Scantool OBD-II scanner

and written some softwareprograms to get all my Jeep parameters logged realtime to my laptopwhile I am driving - a wealth of information, but incomplete. One ofthis days, I will post this information here. However, the scannerprovides no fuel pressure information. Love the scanner, though.

FYI: for a hassle-free installation, you're better off using a crimped connection if you're splicing into a nylon fuel line -- the connectors I've used were specifically tailored to that purpose -- as regular barbs won't cut it. Crimpers vary from the high-dollar, dedicated purpose devices to the [aforementioned] CV-boot variety, depending on the products selected. Try googling "nylon fuel line repair" or something to that effect.

Overkill on pieces, CV-style clamping:

It might be easier to have a local well-equipped garage crimp it up for you. While working on fitting a supercharger, I found an absolute dearth of information and materials for this exact scenario....even the manufacturers show a cobbled-up pile of fittings in their literature.....the performance aftermarket supplies an an-to-male quick-connect fitting for "Mustang" applications, but their female portion is on the rail or something, so it only gets you halfway there....