Carburetor Fuel Regulators

Jeff20B · 05-18-2008, 02:17 AM

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 · 05-18-2008, 07:04 AM

Chris, is your tank vented properly?

orion84gsl · 05-19-2008, 09:57 AM

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 · 05-20-2008, 07:10 PM

It really needs to be vented.

orion84gsl · 06-01-2008, 02:29 PM

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 · 08-10-2008, 09:28 PM

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 · 08-10-2008, 09:38 PM

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 · 08-13-2008, 04:17 PM

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 · 09-09-2008, 08:22 PM

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 · 09-12-2008, 01:19 PM

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 · 09-12-2008, 03:10 PM

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 · 09-27-2008, 07:04 PM

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 · 11-20-2008, 05:52 PM

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 · 11-21-2008, 12:15 AM

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 · 11-21-2008, 02:17 AM

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.

11-20-2008, 05:52 PM	#28
BigTeddy Rotary Fan in Training Join Date: Sep 2008 iTrader: (0) Posts: 46 Rep Power: 0	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 __________________ One Turbo At A Time

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05-18-2008, 02:17 AM	#16
Jeff20B Rotary Fanatic Join Date: Mar 2008 iTrader: (1) Posts: 215 Rep Power: 17	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.

05-18-2008, 07:04 AM	#17
Sterling Premium Vendor Join Date: Feb 2008 iTrader: (2) Posts: 74 Rep Power: 17	Chris, is your tank vented properly?

05-19-2008, 09:57 AM	#18
orion84gsl Rotary Fanatic Join Date: Mar 2008 iTrader: (0) Posts: 167 Rep Power: 17	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.

05-20-2008, 07:10 PM	#19
Sterling Premium Vendor Join Date: Feb 2008 iTrader: (2) Posts: 74 Rep Power: 17	It really needs to be vented.

06-01-2008, 02:29 PM	#20
orion84gsl Rotary Fanatic Join Date: Mar 2008 iTrader: (0) Posts: 167 Rep Power: 17	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?

08-10-2008, 09:28 PM	#21
orion84gsl Rotary Fanatic Join Date: Mar 2008 iTrader: (0) Posts: 167 Rep Power: 17	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?

08-10-2008, 09:38 PM	#22
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	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.

09-09-2008, 08:22 PM	#24
orion84gsl Rotary Fanatic Join Date: Mar 2008 iTrader: (0) Posts: 167 Rep Power: 17	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

09-12-2008, 01:19 PM	#25
Jeff20B Rotary Fanatic Join Date: Mar 2008 iTrader: (1) Posts: 215 Rep Power: 17	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.

09-12-2008, 03:10 PM	#26
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	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.

09-27-2008, 07:04 PM	#27
orion84gsl Rotary Fanatic Join Date: Mar 2008 iTrader: (0) Posts: 167 Rep Power: 17	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.

11-21-2008, 02:17 AM	#30
Jeff20B Rotary Fanatic Join Date: Mar 2008 iTrader: (1) Posts: 215 Rep Power: 17	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.