Carburetor Fuel Regulators

[Sterling]

A customer of mine is having issues with his Holley fuel regulator and his Sterling Nikki. He said he dialogged with another owner of a Sterling who experienced the same issue, but then another with a different carb set-up (I believe) who also had a problem with the Holley regulator.
I've been recommending the Holley 1-4 psi fuel regulator for years, and I had thought this to be the best. This seed was planted in my mind by Paul Yaws insistence upon his customers using that choice, as well.
I had also read many times that the popular alternative, Puralator, failed frequently due to a different diaphragm design.

Though I have cut into fuel pumps to see how they work, I have not dissected a fuel regulator, and do not fully know how they work. I'm assuming they work similarly to flammable gas (propane/acetylene) tank regulators, which I am a bit familiar with.

If anyone has any experience with regulators, please add yours here, and after some experience data is accumulated, I'll know better the parameters I need to set for a poll on this issue.

[Kentetsu]

I've been fighting variable fuel pressures since the day I installed my Holley fpr. I spoke with Billy from Respeed, and he informed me that quite often there are burrs inside the regulator which will impede proper function. He recommended that I disassemble it and smooth out the bore. I'll have to actually get around to doing this within the next couple of weeks, so I'll let you guys know what I find.

To clarify my issue; one time you start the car and you've got 3.75 psi and the next time you start it up you've got 2.5 psi Pretty tough to do any fine tuning with that kind of shit going on... Is this similar to what you are hearing about Dennis?

[djjjr42]

I've had the same variable pressure problem with this regulator installed on one of my FB's with a 45 DCOE and carter pump. It goes up and down randomly, and I had been blaming it on my cheap Summit gauge. However seeing this thread is now making me wonder.
I was wondering if air in the lines might have an effect on the pressure reading, not sure about that but since I used clear fuel lines I can see that there is indeed air in there. Also I'm dead heading with the DCOE.
I'm looking forward to seeing how the Sterling I won, to be installed on another FB compares to the DCOE.

[Sterling]

I'm looking forward to seeing how the Sterling I won, to be installed on another FB compares to the DCOE.
-So am I. ;)

[orion84gsl]

Congrats on the win, I'm sure you'll love it. And Sterling, you can name names. I'm the one thats been bitching to him about my regulator. I believe it may be the culprit behind my starting issues. When it's been awhile, the car will crank but stumble and die on start up. Persistence will get her running, but the pressure is usually high when I check after startup. Same symptoms as Kentetsu. Set it at two and next time I look its at 1 or 4, even 5 once, which was wierd considering the regulator is rated 1-4. What is involved in deburring the regulator? I assume just sanding the inside with a fine grit paper. I'd rather do that than have to shell out for a different regulator.

[orion84gsl]

Whoops, good thing I caught this. Almost a a double post.

[Kentetsu]

I haven't torn into mine yet, I just got the motor/tranny back in this weekend. I think I'll probably use my dremel to clean mine up, so I'll let you know how it goes when I finally get to it...

[PercentSevenC]

Those Holley regulators are crap. I never could get the fuel pressure right on my old GLC. Jeff20B's cheap regulator (I think it might be this one (http://store.summitracing.com/partdetail.asp?autofilter=1&part=SPE%2D2517&N=700+4294925239+4294839053+4294880914+4294891681+ 4294801880+115&autoview=sku)) seems more consistent. I'll be using a rebranded Aeromotive 13301 (http://store.summitracing.com/partdetail.asp?autofilter=1&part=TFS%2D27001&N=700+4294925239+4294839053+4294880914+4294891681+ 4294762074+115&autoview=sku) on my blow-through DCOE project. I'll let you know how it works.

Edit: Apparently Jeff's is actually a Purolator, but I think the Spectre and Mr. Gasket ones are the same.

[Sterling]

I had always read the Purolator regs (which does incorporate several other rebranded names) were terrible.

Looks like I'm going to have to post up some polls on other carbed rotary forums to collect experience data...

[Jeff20B]

I've had that Purolator for years. It always spits out a reliable pressure. Now the Holley regs on the other hand... where's that funny moo-cow sound?

I'm still going to use a Holley reg with the supercharger, but this time I'll employ a guage which I believe to be accurate enough to tell whether the reg is being sour or sweet.

[rx7carl]

The purolator maintains pressure ok but its very restrictive for fuel flow. Fine for a DD stocker, questionable for a performance carb. I have had holley regs on my streetcar and racecar with no problems other than one ruptured diaphragm (easy fix). The holleys are cheap, simple and reliable IMHO. Are you guys deadheading? I was running the stock return line on both cars, not that it should matter. Maybe you dont have the spring correctly seated in the reg?

[Kentetsu]

Mine is not deadheaded.

[rx7carl]

I'd pop the top and check that the spring is squarely seated. They are so frickin simple in design it's hard for them to fail to regulate properly.

[Jeff20B]

I took the top off mine and couldn't see any burrs. I put the top back on carefully so the spring ought to be seated correctly.

It is deadheaded on an Edelbrock. I need to drive it around some more to get some fuel moving through the regulator.

[orion84gsl]

I'll try taking the top of mine off when I park the car to fix the oil cooler. It "seems" to have settled down a bit but the pressure still drops and rises periodically.

[Jeff20B]

I think I got mine to work right. I screwed the stud all the way down, then all the way out and observed the pressure. Some progress. Then almost all the way down and almost all the way up. Even more progress. I was actually able to watch the guage needle move as I cranked the stud. Real progress! I finally setteled on about 5 psi for the Edelbrock. Then I fired it up to an idle and it was right around 5.1 according to the guage. You know how guages can be. I was really only interested in whether the carb would continue to overflow and leak down the side, or actually stay dry. It seems to like 5 psi and even drove ok. I'll leave it there for a while to check for consistancy.

[Sterling]

Chris, is your tank vented properly?

[orion84gsl]

Hard to say. Sometimes it does the WHOOSH when I pull the cap off close to empty, but lately it hasn't been doing it, or I haven't been noticing. I'll have a look in my Haynes and check it out.

[Sterling]

It really needs to be vented.

[orion84gsl]

Well I checked my Haynes manual but it doesn't illustrate any way to properly check if the fuel tank is venting. Can anyone tell me the correct way to check?

[orion84gsl]

Well I spoke to the shop I got my regulator from and they said they see this problem alot. They got me a replacement Holley reg and sent my old one back under warranty. Unfortunatly this did not solve the issue, so either my gas tank ventilation isn't working correctly, or both regs are garbage. Can anyone point me to another regulator, preferably of higher quality than the Holley's that can operate between 1 and 3 PSI?

[Rogue_Wulff]

To check for proper fuel tank venting, wait till a hot day, and pop the fuel cap off. If lots of air rushes out, you have a vent problem.
As for FPR, Mallory makes a decent one, but they're pricey.
The Holley/mr gasket and many lesser known brands are all the same, just a different package. They are also very problematic, as you have seen.

[PercentSevenC]

Mr. Gasket, Spectre, Purolator, and possibly others are the same and seem to be reasonably reliable. Holley is different, but still non-return style.

Malpassi also made a low-pressure non-return regulator, but I don't know if they still do.

[orion84gsl]

Okay well now I know for sure it's not ventilating properly. Lots of whooshing this summer. Can anyone give me some pointers for fixing the problem? Does it involve dropping the tank? *cringes*

[Jeff20B]

The dumb little checkball thing is probably malfunctioning, as I suspect was happening on percent's car. It is located above the rear end, bolted to the highest pont of the floorboard. It connects to the vent nipple on the tank, has two other connections; one running over to the frame rail and the other is the small tube running to the engine bay.

[Rogue_Wulff]

First place to check for tank venting issues, is the charcoal canister under the hood. The small hose on the CC is the tank vent. That nipple has a tiny orifice inside it, and that can clog easily. A fine wire or torch cleaning tool works great for opening that orifice up. In extreme cases, a 1/8" drill bit will put a permanent solution to the problem.

[orion84gsl]

OK thanks Jeff and Rogue, I'll give those a try next time I get a chance to work on the car. Appreciate the help.

[BigTeddy]

Main problem with not getting a good reading on the reg's is sometimes he/she run to big of return line on the fuel...which is not allowing the fuel press reg read correctly...In that instance fuel is just flowing to from and back from the tank however it feels with no built up pressure....

On my setup with the racing beat intake mani and holley 600 i don't have a return...there is no need...press reads fine and is set at the desire i want it and the carb will only take what it wants either way...So all in all its a win win situation

[PercentSevenC]

It's worth noting that the Mr. Gasket regulator Jeff installed on his Baja the other day failed, causing gas to gush out all over the engine. Upon closer inspection, it's different from the older Purolator that he replaced it with. The Purolator said "made in USA" on it, but the Mr. Gasket one didn't say anything, and seemed to be of lesser quality. It was probably made in China or something.

So, I withdraw my recommendation for that regulator style. Jeff's Holley reg on his supercharged car has been doing its job since he got it working correctly. My Malpassi appears to be of good build quality, but I don't think they are in production anymore.

[Jeff20B]

Man what a gassy mess. I threw on one that was old when I got it, ten years ago. It still works fine. Quality USA stuff, there.