7.4 MPFI and external Fuel pressure regulators.

[Mangonesailor]

Hey ya'll,

So recently I've found, again, that my fuel pressure is low at idle. It's about 50psi KOEO, 48 KOER, and 45 when I rev it. This'll make the 4th FPR I've had to put in this truck in the past 3 years. I'm not interested in putting $50 in it every year for something as painstaking as replacing such a simple component.

I've been looking into external fuel pressure regulators, and what brands there are and just what's out there. I'd like to install one downstream of the current one (which would just nullify any attempt by the factory FPR to reduce pressure anyways). I was thinking as well about replacing the fuel lines, as they're old, and I'll probably end up upgrading the fuel pump to a walbro 450 (especially if the FPR isn't bad and I need a new pump)

Is there anyone that's done this before? Does anyone have a brand they recommend that they've used in other applications? I've been looking at the JEGs, AEM, Aeromotive, Tanks inc., and fuel lab. I can likely get a local performance shop to set me up with the fittings I need, but I know the return size is 3/8". I intend to splice it into the return line and probably mount it to the frame rail or maybe against the firewall. I just want to keep it near the drivers seat as I'm going to get a fuel pressure gauge from AEM as well so I have feedback in the cab... I could even log the data with HPtuners I'll bet as well.

When I do this, I'll be sure to have a writeup in this thread so others can do the same.

 

[Mangonesailor]

I think I'm going to go with an aeromotive 13129, with An fittings straight to the lines from the replacement line kit without adapters.

I can't fine 16mm thread adapters that won't make the whole ordeal full of connections that just increase the likelihood of a leakage or failure later.

Parts list coming soon.

 

[Christian Steffen]

Hey ya'll,

So recently I've found, again, that my fuel pressure is low at idle. It's about 50psi KOEO, 48 KOER, and 45 when I rev it. This'll make the 4th FPR I've had to put in this truck in the past 3 years. I'm not interested in putting $50 in it every year for something as painstaking as replacing such a simple component.

I've been looking into external fuel pressure regulators, and what brands there are and just what's out there. I'd like to install one downstream of the current one (which would just nullify any attempt by the factory FPR to reduce pressure anyways). I was thinking as well about replacing the fuel lines, as they're old, and I'll probably end up upgrading the fuel pump to a walbro 450 (especially if the FPR isn't bad and I need a new pump)

Is there anyone that's done this before? Does anyone have a brand they recommend that they've used in other applications? I've been looking at the JEGs, AEM, Aeromotive, Tanks inc., and fuel lab. I can likely get a local performance shop to set me up with the fittings I need, but I know the return size is 3/8". I intend to splice it into the return line and probably mount it to the frame rail or maybe against the firewall. I just want to keep it near the drivers seat as I'm going to get a fuel pressure gauge from AEM as well so I have feedback in the cab... I could even log the data with HPtuners I'll bet as well.

When I do this, I'll be sure to have a writeup in this thread so others can do the same.

I've been thinking about doing this too. It gets really old worrying about that fpr. That aeromotive should be a very nice unit.

So you're running all new line from the tank? Are you going to tie it into the factory fuel rail? It should be possible to read your gauge into HPT, you have the pro unit right? As long as you have 0-5v output. Otherwise you could get a separate pressure sender that is 0-5v and wire that in.

 

[454cid]

A spin on filter would be nice too.

 

[Mangonesailor]

I've been thinking about doing this too. It gets really old worrying about that fpr. That aeromotive should be a very nice unit.

So you're running all new line from the tank? Are you going to tie it into the factory fuel rail? It should be possible to read your gauge into HPT, you have the pro unit right? As long as you have 0-5v output. Otherwise you could get a separate pressure sender that is 0-5v and wire that in.

I was going to end up getting a fuel line replacement kit off Rock Auto (PN in original post). Cutting the flexible line on the return section and tying in the FPR to them.

However, I may cut the ends of the fuel line off and reflare it to put different, longer lines on. I'd like the FPR up top in the engine bay somewhere (but we know real estate is precious)

Yes, I have the pro version, and a sending unit is on the short list. The unit is tapped already.

 

[Mangonesailor]

This might work.

 

[Christian Steffen]

That looks like it would work well. Personally, I would do whatever it takes to get the fpr in a nice location, just so any later service is easy.

 

[Mangonesailor]

So, my full shopping list from summit looks like this:

AEI-13129, FPR, $141
EAR-610006ERL, Hose 10', $66
EAR-AT165056ERL, Tube to hose AN, $11 x2
EAR-AT949006ERL, AN to FPR, $16.95 x2
Total to upgrade: $263.99

It will end up bumping up the hose size on the return from 5/16" to 3/8", which is not a bad thing. It'll add a little pressurized volume to the system, plus I can use the factory lines by just cutting off the existing ends.

Got it back from the exhaust shop today as well. $20 to install the o2 bung and fix the little pin holes in a weld joint. So, now I just need to get this all together.