Fuel pressure running off at the worst time

Bob Gullett · 02-24-2012, 10:31 AM

After installing my Magnafuel system I was having a problem with the large port regulator as well. Out of the blue the pressure would spike pegging my guage and of course blowing the needle and seat off the q-jet. I contacted magnafuel and they suggested along with the rear fuel filter to add an inline filter just before the regulator. Since I have done that never an issue again. They claim that the regulators are very sensative and the smallest particle of anything can cause the regulator not to work properly.

Paul Merolla · 08-12-2013, 10:14 AM

Quote:

Originally Posted by Bob Gullett

After installing my Magnafuel system I was having a problem with the large port regulator as well. Out of the blue the pressure would spike pegging my guage and of course blowing the needle and seat off the q-jet. I contacted magnafuel and they suggested along with the rear fuel filter to add an inline filter just before the regulator. Since I have done that never an issue again. They claim that the regulators are very sensative and the smallest particle of anything can cause the regulator not to work properly.

Bob - I'm having the same problem and will be adding a filter before the regulator. It happened when I was trying to start the car Thursday night to load up for Cedar Falls...filled # 7 cylinder with fuel, along with the crankcase. What filter did you use? Is it a finer mesh than the one at the rear of the car? Thanks.

Bob Gullett · 08-12-2013, 10:37 AM

http://www.summitracing.com/parts/mrf-mp-7010
http://www.summitracing.com/parts/mrf-mp-3013
This is the filter and fittings I use and Magnafuel recommends. I would recommend after installing it run the pump for a few seconds with the line from the carb removed into a container to flush anything out.

Paul Merolla · 08-13-2013, 07:21 AM

Thanks, Bob.

bert powell · 08-13-2013, 09:28 AM

Funny this has come to the top again! Adding the fuel filter before the reg fixed the original problem for me! I try to clean the reg regularly.

Just this past weekend I was going to load the car in the trailer and the fuel pressure was good before starting -7psi. When running it would drop down slowly to 3psi and then go to zero. Cleaned the reg and tried another carb, same thing. Going to check the pump next.

Been wanting to switch to a bypass reg, this may be the time...

HTMtrSprt · 08-14-2013, 12:24 AM

It may also help if you run a return line from the carb feed line (post regulator) back to the fuel cell with a .025 - .030" restrictor in it. This would allow a constant, small amount of fuel to always be flowing through the regulator which seems to help them maintain a more stable pressure.

Ian Hill · 08-14-2013, 11:37 AM

Quote:

Originally Posted by HTMtrSprt

It may also help if you run a return line from the carb feed line (post regulator) back to the fuel cell with a .025 - .030" restrictor in it. This would allow a constant, small amount of fuel to always be flowing through the regulator which seems to help them maintain a more stable pressure.

So your saying to turn your non-by pass regulator into a by pass regulator...

I'd add, if your going to do this modification then change to a bypass ragulator, add a full size return line and at least get the benifits of a cooler running fuel system, rather than adding a #4 line back to the tank.

Ian

02-24-2012, 10:31 AM	#1
Bob Gullett VIP Member Join Date: Mar 2002 Posts: 1,108 Likes: 58 Liked 510 Times in 117 Posts	Re: Fuel pressure running off at the worst time After installing my Magnafuel system I was having a problem with the large port regulator as well. Out of the blue the pressure would spike pegging my guage and of course blowing the needle and seat off the q-jet. I contacted magnafuel and they suggested along with the rear fuel filter to add an inline filter just before the regulator. Since I have done that never an issue again. They claim that the regulators are very sensative and the smallest particle of anything can cause the regulator not to work properly. __________________ 68 Chevy11 327 F/S Last edited by Bob Gullett; 02-24-2012 at 10:35 AM.

08-12-2013, 10:37 AM	#3
Bob Gullett VIP Member Join Date: Mar 2002 Posts: 1,108 Likes: 58 Liked 510 Times in 117 Posts	Re: Fuel pressure running off at the worst time http://www.summitracing.com/parts/mrf-mp-7010 http://www.summitracing.com/parts/mrf-mp-3013 This is the filter and fittings I use and Magnafuel recommends. I would recommend after installing it run the pump for a few seconds with the line from the carb removed into a container to flush anything out. __________________ 68 Chevy11 327 F/S Last edited by Bob Gullett; 08-12-2013 at 10:45 AM.

08-13-2013, 09:28 AM	#5
bert powell Member Join Date: Jul 2002 Posts: 243 Likes: 36 Liked 34 Times in 12 Posts	Re: Fuel pressure running off at the worst time Funny this has come to the top again! Adding the fuel filter before the reg fixed the original problem for me! I try to clean the reg regularly. Just this past weekend I was going to load the car in the trailer and the fuel pressure was good before starting -7psi. When running it would drop down slowly to 3psi and then go to zero. Cleaned the reg and tried another carb, same thing. Going to check the pump next. Been wanting to switch to a bypass reg, this may be the time...

08-14-2013, 12:24 AM	#6
HTMtrSprt Junior Member Join Date: Oct 2007 Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Re: Fuel pressure running off at the worst time It may also help if you run a return line from the carb feed line (post regulator) back to the fuel cell with a .025 - .030" restrictor in it. This would allow a constant, small amount of fuel to always be flowing through the regulator which seems to help them maintain a more stable pressure.

08-13-2013, 07:21 AM	#4
Paul Merolla Senior Member Join Date: Dec 2001 Location: Papillion, NE Posts: 612 Likes: 245 Liked 293 Times in 65 Posts	Re: Fuel pressure running off at the worst time Thanks, Bob.