Fuel Pressure Regulator require CG approval?

[John_S]

The techs at Summit say that a fuel pressure regulator does not have to be Coast Guard approved because it has no electrical connections or weep hole. I would expect everything in the fuel path would need approval or specific rating. Does anyone know or have a link to docs that would help. Thx.

 

[Bondo]

Re: Fuel Pressure Regulator require CG approval?

Ayuh,.... I can't answer your Question,....

But,... I find Myself asking,... Why do you want 1,..??

The Stock fuelpump should be able to feed your Carb,... No Problem...

 

[John_S]

Re: Fuel Pressure Regulator require CG approval?

I am getting 8psi (within Merc specs) out of my pump, and Edelbrock recommends a regulator for anything over 6.5psi. I am getting missfires when hitting waves and sharp turns, and occasionally at other times. The missfires are happening on the end cylinders, 7 & 8. Mostly 8. Plugs are fine, unless the missfire, then they are black. All electrical has been verified.

 

[wca_tim]

Re: Fuel Pressure Regulator require CG approval?

I had almost exactly the same problem with my electric fuel pump when I swapped engines out this last time from v-6 to v-8. I opened up the supply line and put a bigger vent in the tank because it was running out at first, then all of a sudden the pump would over pressure the carb just a little bit and only sometimes. Once in a while would flood out, usually when warm and then start and be fine.and finally I caught it doing it and it was pushing the needles open and dumping gas into the intake. I was trying to get the fuel mixture right and having sort of random fuel mixture changes, and some of what you are seeing occassionally. I thought it was the new carb and even put different jets in the one of my v-6 and put it on the boat just to see if that cured it for the time being (edelbrock 1409 and 1410)... when I saw the same thing it took a while to figure it out. I bought a cheap fuel pressure gauge and that was it. It would push by the needles some of the time even at a little below 7 psi. I tried a fuel pressure regulator I had on hand and found that the cheaper ones did not keep up with the v-8 and got surging at wot... I finally swapped out the fuel pump and put a mechanical on on it. It does spike up to 7 sometimes and I've wondered if some of the minor but somewhat erratic changes in performance characteristics are due to slight changes in fuel mixture from it pushing some gas by the needles, etc... (minor, not enough to change plug read or anything) and have thought about putting a regulator on it. It's not been bad enough to motivate me to mess it with in a hurry. Please do a favor and post whether or not it makes a difference for yours. It makes sense...

 

[John_S]

Re: Fuel Pressure Regulator require CG approval?

I found this site: http://www.uscgboating.org/safety/boatbuilder/fuel/fuel.htm
but, it doesn't have anything specific on regulators.

Mine is a mechanical pump. It remains steady at or very near 8psi at the specific test rpm down to idle rpms. The line from the pump to the carb is new, along with the water seperator filter (this spring).

The regulator I have been looking at is: http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-12-704&N=700+0&autoview=sku Its oriface is twice as large as the lower cost regs, and says it is alchol rated.


My thoughts are that when a mechanical fuel pump wears, it would go down in pressure, not up. I thought the spring in the pump, along with the diaphram size, determined the pressure and volume. If I knew a new pump would get it down to 6psi, would just buy a new pump.

 

[wca_tim]

Re: Fuel Pressure Regulator require CG approval?

thanks for the info. if I need to go with one, I'll probably follow your lead. So far the newer fuel pump is working fine. I was running an electric (carter, marine spec) originally.

Once I changed out the restrictive fittings and tank screen up stream of the pump it consistently overran the needles and the quickest / easiest way to fix it and get us back on the water was to pick up a marine mechanical fuel pump at napa and swap it out. I don't know for sure if I need a regulator or not with the edelbrock, but will probably get one just for safe measure if I stay with that carb.

My mechanical is putting out about 5.5 with spikes up to 7 or a little higher at idle and a little over when running on muffs.

I'm setting up a 750 Holley double pumper right now and will probably get it on in the next week or so. I want to see how that runs once dialed in. Once I know for sure which carb I'm going to stick with in the longer run, I'll decide whether to add the regulator or not.

I will be interested to know if evening out / reducing your fuel pressure to the recommended ca. 6 psi takes care of the symptoms you're seeing.

Cheers!

ps. I do really appreciate all of the things I've learned from you and some of the others as well as patience with some of the questions...