Holley sniper efi 2

[themoparman73]

Hello Fabo family
I was wondering where are you guys mounting your electric fuel pumps? I have mine right under the passenger side. The reason I'm asking is I'm losing fuel pressure and my fuel Guage only goes up to 40 psi. I have adjusted the screw on top of my regulator and still the same. Car runs for 6 mins then lose pressure. I have both filters hooked up and no fuel lines bent.
Any advice would be great.
Thanks

 

[67Dart273]

I'd say you have something basic wrong. A tank filter sock partly plugged, or maybe sucking up against the end of the pickup tube. Junk in the tank/ suction tube, etc, something like that. You have a suction filter? You said "both." Are you certain whatever you are using for a suction filter is rated for the low pressure? They must be low pressure, hi flow

 

[Johnny Mac]

Several things here.
1. Holley regulators have been failing left and right. We sell a ton of sniper 2 equipped engines, and have had many customers call back and buy our billet regulator because their holley regulator failed. Just saved the day for a guy driving his truck 5 hours home with one of these, when his holley diaphragm blew out. EFI Billet Aluminum Fuel Pressure Bypass Regulator - 40-75 PSI and -6AN ORB

2. Inline pumps are pushers, not pullers. Needs mounted as low as possible.
3. What fuel filter is on it? Not impossible you stirred up some junk in the tank, and a 5 or 10 micron fuel filter is clogged.
4. If your return line is not dropped below the fuel level, you can aerate the fuel when low, causing pressure drop.
5. I have also seen an increase in failed walbro type inline pumps. They used to be the go-to, but I have seen plenty fail recently.

Hope that helps.

 

[themoparman73]

67Dart273

I'm running the two filters that they sent in the kit. Maybe I got some junk in them. I'll replace them this weekend. Bought the tank new nine years ago. Might be the regulator. I'll try out the filters first. Of not the regulator.

 

[themoparman73]

Johhnny Mac
Going switch out the filters. If that don't work then I'll see if the regulator is the problem.

 

[Johnny Mac]

Johhnny Mac
Going switch out the filters. If that don't work then I'll see if the regulator is the problem.

Doesn't take much to plug up a 10 micron filter. Always good to have a spare.
the holley plumbing kit leaves alot to be desired. we offer an AN type kit with PTFE hose.
hindsight is always 20-20 haha.
EFI Fuel Pump and Plumbing Kit BPP5267 - For Fuel injected engines

 

[themoparman73]

well changed out the filters and still doing the same thing. pressure only went up to 50 then slowly went all the way don to 0. ran about 5-6 mins then shut down

 

[1WildRT]

1967-70 Dodge Dart / 1967-69 Plymouth Barracuda Fuel Injection Gas Tank

In-Tank Fuel Pump Module - PA-Series

Floatless Fuel Sending Unit

 

[Newbomb Turk]

Several things here.
1. Holley regulators have been failing left and right. We sell a ton of sniper 2 equipped engines, and have had many customers call back and buy our billet regulator because their holley regulator failed. Just saved the day for a guy driving his truck 5 hours home with one of these, when his holley diaphragm blew out. EFI Billet Aluminum Fuel Pressure Bypass Regulator - 40-75 PSI and -6AN ORB

2. Inline pumps are pushers, not pullers. Needs mounted as low as possible.
3. What fuel filter is on it? Not impossible you stirred up some junk in the tank, and a 5 or 10 micron fuel filter is clogged.
4. If your return line is not dropped below the fuel level, you can aerate the fuel when low, causing pressure drop.
5. I have also seen an increase in failed walbro type inline pumps. They used to be the go-to, but I have seen plenty fail recently.

Hope that helps.

Failing Holley regulators?????

Say it isn’t so lol.

 

[67Dart273]

well changed out the filters and still doing the same thing. pressure only went up to 50 then slowly went all the way don to 0. ran about 5-6 mins then shut down

What do you have for a tank pickup? You have any tap points where you can monitor pressure? One way to do that which I like, LOL, because I used to do HVAC/R service, is to use refrigeration Schrader valves. I use an old manifold with a different, lower pressure gauge on one side, and the (blue) low side gauge if I need higher pressure for EFI. I use an old set of hoses, so they are not mixed with my refrigerant gauge sets

Another way you can do that for temporary/ troubleshooting is to find/ buy a couple of pressure/ vacuum senders in the proper ranges. You don't need matching gauges, just find out the resistance vs pressure output of the sender. With a chart, you can justify ohms readings to pressure

Does the Sniper electrically modulate the pump? Or just "relay" activate it? Maybe it's losing power from the EFI?

 

[Johnny Mac]

Failing Holley regulators?????

Say it isn’t so lol.

They are really bad. Lol. I know I haven't had one of my billet ones come back. Haha

 

[Killer6]

What do you have for a tank pickup? You have any tap points where you can monitor pressure? One way to do that which I like, LOL, because I used to do HVAC/R service, is to use refrigeration Schrader valves. I use an old manifold with a different, lower pressure gauge on one side, and the (blue) low side gauge if I need higher pressure for EFI. I use an old set of hoses, so they are not mixed with my refrigerant gauge sets

Another way you can do that for temporary/ troubleshooting is to find/ buy a couple of pressure/ vacuum senders in the proper ranges. You don't need matching gauges, just find out the resistance vs pressure output of the sender. With a chart, you can justify ohms readings to pressure

Does the Sniper electrically modulate the pump? Or just "relay" activate it? Maybe it's losing power from the EFI?

I already suggested He monitor the voltage at the pump, last post of the 1st thread He started on this system. I too wonder if the driver is varying the pump rpm via pulse width on either voltage in or ground.
Or, it could simply be losing a good ign.(+)V or run/rpm pulse signal.

 

[jbc426]

On my '68, I used the stock tank and modified my fuel sending unit to hang the pump on. Being submerged in the tank helps cool the fuel pump.

You can also add a Holley Hydromat if you are not going to run a surge tank to eliminate the chance of fuel slosh affecting your fuel pressure.

This sending unit modification combined with a surge tank set-up will eliminate the need for fancy "baffled" tanks that barely work, and provide you with a steady, air-free supply of fuel even when you are down to the last gallon or two in the tank and ripping around a road course.