Fuel Pressure regulator project

[Normspeed]

I finally put aside the teardrop and tractor projects and decided today was the day I would install my vintage Moon fuel block, Holley pressure regulator, new pressure gauge, and blue urethane flex lines. A simple project, considering I had stockpiled all the fittings, clamps, small parts, plus I had pre-assembled all the fittings into the old used Moon fuel block, which had some questionable threads in the alloy.

Turned out to be what a friend calls a "Merely and Simply" job. Merely remove the old lines and simply install the new ones. Wrong.

Whatever could go wrong or could be difficult did so. Dropped wrenches disappeared into the never land of underhood hiding places. Fittings were incorrect. Every step took 3X as long as it should. Good thing I enjoy this kind of challenge.

Had to stop work for a run into town for additional brass fittings. Had to stop again later to feed the dogs (and me). Around 8pm I wrapped it up (I thought) and turned on the electric pump. leaks everywhere. One of them, at the regulator outlet, was maddening. re-cut the hose, changed to another clamp, tightened the brass fitting to superhuman specs, it still seeped. I began to suspect a flaw in the Holley casting. Last chance, I swapped out the brass hose nipple. Leak stopped. It was a faulty brass fitting, right outta the box with a pinhole leak. Aha, leaks solved. Wrong again. I let the pump run for several minutes. Just as I was about to wrap it up, one of the fuel block fittings began pouring gas. Bad threads in the fuel block. Nice waterfall effect on the firewall.

Worn out, reeking of gasoline, humbled by the Mopar Gods, I called it quits for the night at 9pm. I'll need a nice new fuel block before I can finish the job. No sense in risking an engine fire just to use a neat looking vintage part. Can't believe I just spent 9 hours on a 2 hour job.

[RobertKB]

Normspeed, it looks like Murphy's Law was paying you a visit! It's amazing how some jobs should be simple but are simply awful. Your sticktuitiveness is admirable. Let us know how things turn out.

[Don Coatney]

Can you drill and tap a 1/4" IPS hole in the fuel block where you have bad threads? Looks like there should be ample meat to do so. What kind of pipe dope did you use to seal the threads?

[Normspeed]

It could be drilled and tapped Don, but I don't have a drill press and I'd hesitate to do it all with a hand drill. This is a neat fuel block but with 5 holes including one at each end, every one of them has bad thread damage. Almost looks like corrosion more than cross threading. One of the holes only had intact threads in the bottom third. I used Hylomar Blue a good non hardening fuel proof sealer.

I went ahead and ordered a Mr. Gasket from Summit. Less than $20 with shipping. While I'm waiting for that I guess I'll take off the Moon and fix it with my favorite secret 2 part formula:rolleyes:

After I get the Mr. Gasket I'll check with the local machinist about repairing the Moon the right way. What would you think a machinist would charge to drill and tap 5 holes in alloy?

BTW, I noticed when installing it on the firewall, MOON spelled upside down is NOOW.

[Don Coatney]

It could be drilled and tapped Don, but I don't have a drill press and I'd hesitate to do it all with a hand drill. This is a neat fuel block but with 5 holes including one at each end, every one of them has bad thread damage. Almost looks like corrosion more than cross threading. One of the holes only had intact threads in the bottom third. I used Hylomar Blue a good non hardening fuel proof sealer.

I went ahead and ordered a Mr. Gasket from Summit. Less than $20 with shipping. While I'm waiting for that I guess I'll take off the Moon and fix it with my favorite secret 2 part formula:rolleyes:

After I get the Mr. Gasket I'll check with the local machinist about repairing the Moon the right way. What would you think a machinist would charge to drill and tap 5 holes in alloy?

BTW, I noticed when installing it on the firewall, MOON spelled upside down is NOOW.

I would think a machine shop would not charge much. Do you have the correct sized drill and tap? You could do it by hand.

I noticed that NOON spelled upside down is still NOON...........

[martybose]

Norm,

I would suggest that you carefully check that nice fuel hose to see if it has any markings. If, like the hose I bought, it is marked "FDA approved", I would throw it away. My so-called fuel hose turned out to be a food-grade plastic tubing that had the interesting habit of swelling up with today's gasoline. I spent two weeks chasing leaking connections before I threw it away and switched to a fuel grade reinforced hose.

YMMV.

Marty

[Normspeed]

Thanks for the tip Marty. This stuff is made of polyurethane and supposed to be fuel grade. I got it from a snowmobile supply place online.

http://www.hiperf.com/ATV/acatalog/ATV_Catalog_Fuel_Filters___Fuel_Line_139.html

Don, I disassembled, cleaned and reassembled with JB Weld instead of thread sealant. Looks good and I'll find out just how fuel proof (fool proof?) JB is. I'll always have the Mr. Gasket unit for a spare. In this pic, the only part not using JB is the gauge to brass connection, in case Ineed to take the gauge out later.

The only part I'm still lacking is the correct brass fitting for flex line to carb inlet fitting. None of the locals had them so I'll check with Mcmaster-Carr. It needs to be a 90 degree with the male inverted flare fitting on the carb side and the 5/16" hose nipple on the other side. For now I'll use my old steel line inlets, cut off the old hard line setup. Hope to post a photo of the finished, non-leaking job a little later today.

[Normspeed]

Finally got it back together today. No leaks at all. I also replaced the inlet needle and seat on the front carb and installed the chebbie carb spacers I picked up recently. In the Murphy's Law spirit of this project, the addition of the spacers meant all new longer carb studs. Also could not locate the oddball brass 90 degree carb inlet stuff so I cut down and re-flared some of the old hard fuel lines for now. The regulator is factory set at 3 lbs and seems very accurate. Just a couple final tweaks like fastening the feed line to the firewall and I'll stamp this one: CASE CLOSED.

Part of all this was to route the fuel supply far from the exhaust as possible and to reduce fuel pressure in the system. I also installed a nice fuel pump heat shield, many thanks to Blueskies on that.

I think it's gonna work out fine.

[Don Coatney]

Norm;

If your NOOW fuel block failes after your bondo repair you might check the bay. I picked up this Mr Gasket fuel block a couple years back for less than ten bucks.

[Normspeed]

Thanks Don. I already ordered a new Mr. Gasket from Summit on Ebay for a little less than $20 net. I didn't want to wait for delivery so I "fixed" the NOOW unit. I'll keep the Mr. G handy on the road incase the JB Weld fails.

[greg g]

One more project would be to loose those 4 inch aircleaners. Or at least do away with the covers. They look nice but are restrictive. I made up a single filter using a couple pieces of sheet metal and an oval filter element. Esed the bottoms of the 4 inch filters and mounted the new pieces on top of them. Made quite a bit of difference in the looks of the plugs especially on short runs aroud town.

[Normspeed]

Greg, I was first running the non-louvered air cleaners and felt they were pretty restrictive. I switched to the louvered ones and recently went from paper filters to reusable fabric elements. I'll be monitoring the plugs to see how things are going. I'm about to embark on a long road trip, over 3,000 miles, so I should get a good read on the plugs.

I'll be interested to see if there are any performance changes using the carb spacers too.

[Normspeed]

Well in spite of all the work, and no visible leaks, I was still getting way too much raw gas smell, especially after shutting down. I've really gotten to hate the smell of raw gasoline lately. On very close inspection, I found the short flex hose to the mechanical pump was cracked. Not enough to leak and drip, just enough to stink up the place. I replaced that part just a couple years ago. I also observed the outlet line from the (dummy) mechanical pump sending air bubbles up through the clear fuel line when the motor was shut off and hot.

Then the real eye opener. I went for a drive, came back, fuel pressure right at 3 lbs. Let the motor idle with the electric pump turned off until the pressure went to zero. Shut it down. 15 minutes later, walked by, smelled gas again darn it! Opened the hood. No visible leaks but fuel pressure was at 7 lbs, and that's with a vented cap. Guess the anti-backflow valve on the electric pump was doing a real bangup job, and the engine heat was raising the fuel pressure until it forced its way past one needle and seat. I got under the car and removed the anti backflow valve. Gosh I hope this does it, I am so tired of smelling fumes.

The valve is the little extension in this photo, on the intake side of the pump. It was a snap to remove and bypass. Should not cause any priming problems, this pump is real strong.

[Frank Elder]

Rookie questions, can a pump overpower a regulator?

Or can a regulator become weak overtime? Can debris keep it from adjusting properly, say you set it for x psi and then later when the lodged debris comes loose will it rise up to y due to less restricted flow?

[wallytoo]

Rookie questions, can a pump overpower a regulator?

Or can a regulator become weak overtime? Can debris keep it from adjusting properly, say you set it for x psi and then later when the lodged debris comes loose will it rise up to y due to less restricted flow?

i don't know about "generic" pressure regulators, but the holley (which norm used) is pretty bullet-proof. i've been running one on my cj for 5 years with no problems. the weber k551 is very sensitive to excess fuel pressure, so i set the regulator to 2.0 psi. installing the regulator cleared up all of my idle issues. there's also an in-line fuel filter between the pump and the regulator, so that should help prevent excess crud build-up.

edit: the mechanical pump on the cj's 258 puts out between 5 and 7 psi, which would bury the weber. since the weber performs great now, i have to assume the regulator isn't being "overpowered". i've checked the pressure a few times, and it still reads 2.0 psi, 4 years later. didn't check it this year at all.

wally

[greg g]

Isn't our pressure supposed to be 7 lbs give or take a bit??

[Grandadeo]

BTW, I noticed when installing it on the firewall, MOON spelled upside down is NOOW.

That's the problem, it's not a MOON fuel block it's one of those NOOW offshore knockoffs. I'd take it back to the guy you got it from and see if it's still under waranty. BTW, talked to Gary last weekend at River Ranch and saw the new car. He made it back fine and was real proud of his new find.

Lee

[Normspeed]

Lee, the guy that I got it from said the NOOW logo made it more valuable, like a postage stamp with an upside down picture.

Frankie, I think all those things could possibly happen.

Today I drove around, running errands, all seemed well, then at the last stop I came out to the stinkin raw gas smell again. This was a bad situation beacuse I had just come out of a local gun shop and very nearly went back in to purchase a cheapo gun and put the P24 out of its misery. Drove home and found something interesting, and learned a lesson. Hylomar is an excellent fuel proof gasket sealant. It is not a good thread sealant. The new leak was at a brass pipe plug blockoff on the regulator, sealed with Hylomar. I fixed with the white tape style pipe dope. No more leaks...for now. I believe there is maybe only one or two pipe fittings on there that still have Hylomar. The rest are either JB welded or pipe doped.

Live and learn!

[knuckleharley]

I..... Can't believe I just spent 9 hours on a 2 hour job.

I can. I do it more often than I like to think about.

[Normspeed]

Isn't our pressure supposed to be 7 lbs give or take a bit??

Greg, my manual says 4 to 5 1/2 PSI. I went with 3 because I'm suspicious of my old carbs, even with rebuilds and fresh float needles/seats. If this doesn't clear up soon, I'm gonna name her..."Leakin and Reekin"

[wallytoo]

Hylomar is an excellent fuel proof gasket sealant. It is not a good thread sealant. The new leak was at a brass pipe plug blockoff on the regulator, sealed with Hylomar. I fixed with the white tape style pipe dope. No more leaks...for now.

norm,

i used white teflon tape wrapped around the threads on mine. it has held up for over 4 years.

[Normspeed]

Finally got all the threads sealed well. I used the white tape. Assuming that Hylomar would make a good thread sealant was wrong. Still the best fuel proof gasket sealer I've found though.

I think I may have outsmarted myself with the practice of running the carbs dry before shutdown. One advantage of the transparent lines is you can see what's up in those fuel lines. I found that switching off the pump and letting it run, it would quit when one of the carbs went dry, but there is a lot of fuel still in the system between regulator and carbs. Gravity and temp related residual pressure can push fuel slowly back into the carbs which at that point have the floats dropped and needle and seat open. For now I'll go ahead and let the electric work with the ignition key, leaving 3 psi of presure at the carbs when I shut it down. The needle/seats should do their job and keep fuel from seeping in and flooding the carb(s).

I'll drive it for a while and see if I'm satisfied with the results. My upcoming road trip should be a good test. I expect to run approx 4,000 miles in 6-7 weeks.