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Aeromotive FPR - be careful

Tfrasca

Active member
Joined
Apr 20, 2015
Location
Ben Lomond, CA
So, I've had this Aeromotive FPR on my 142 since I did the engine swap. It's about 6 months old, I'd say.

It never help line pressure after the pumps primed, and the needle on the gauge always fluctuated up to 7-8 psi. I was getting my TLAO chips dialed in with my light blue (390cc?) injectors, but I couldn't escape a nasty lean condition under boost toward 5k rpm. Increased fuel pressure to 58 psi, and the FPR would BARELY get there. It should be capable of 30-70psi base pressure, so I took it apart to see what was up.

Sure enough, the hole that the ball valve should seal against was worn unevenly. They apparently just drill a hole, after the base is already anodized, and don't put a radius or chamfer on it. I used a counter sink bit and milled a chamfer on the seat by hand, carefully.

It seals much better now. Still leaks residual pressure after 10-15 seconds, but holds running pressure rock steady on the gauge. I've adjusted FP back down to 43 psi and am actually a bit rich at 12 psi with a 19t.

TL;DR - Be careful with these Aeromotive FPRs. Had I not installed a wideband when I did, I probably would have lost a piston...
 
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I had one start leaking about a month ago due to a leak in the diagrams, and it was only 3 years old.
 
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I had one start leaking about a month ago, and it was only 3 years old.

From the diaphragm? I also noticed the AN plug I used (provided by the FPR supplier) to plug the second input was very slightly fouling on the metal part of the diaphragm. I'm sure that would have caused issues if left unchecked.

I'm still leery of leaving this thing on here. Did you replace the Aeromotive with something else?
 
I've had this "trick flow by aeromotive" one for about 7 years now.

It usually won't hold rest pressure for more than 10-20 minutes, but once in a while it does. Running fuel pressure has always been pretty solid and I even initially cranked the base pressure way up to test the system for leaks and it didn't have fluctuations.

I always thought about opening it to see if the rest pressure could be improved, but never have.
 
Man, that's kinda sad. I thought they were one of the better brands. Any chance you maybe ended up with a knockoff? Just curious, knowing how much knockoff stuff is out there.
 
Man, that's kinda sad. I thought they were one of the better brands. Any chance you maybe ended up with a knockoff? Just curious, knowing how much knockoff stuff is out there.

I suppose it's possible that mine is a knockoff. But, the Aeromotive FAQ acknowledges the poor seal as it pertains to holding residual line pressure. And that's the same problem that causes erratic running pressure.
 
So, I've had this Aeromotive FPR on my 142 since I did the engine swap. It's about 6 months old, I'd say.

It never help line pressure after the pumps primed, and the needle on the gauge always fluctuated up to 7-8 psi. I was getting my TLAO chips dialed in with my light blue (390cc?) injectors, but I couldn't escape a nasty lean condition under boost toward 5k rpm. Increased fuel pressure to 58 psi, and the FPR would BARELY get there. It should be capable of 30-70psi base pressure, so I took it apart to see what was up.

Sure enough, the hole that the ball valve should seal against was worn unevenly. They apparently just drill a hole, after the base is already anodized, and don't put a radius or chamfer on it. I used a counter sink bit and milled a chamfer on the seat by hand, carefully.

It seals much better now. Still leaks residual pressure after 10-15 seconds, but holds running pressure rock steady on the gauge. I've adjusted FP back down to 43 psi and am actually a bit rich at 12 psi with a 19t.

TL;DR - Be careful with these Aeromotive FPRs. Had I not installed a wideband when I did, I probably would have lost a piston...

What main pump are you running? what are you doing for wiring? do you have a inline check valve fitting on the pump. mine drops off pressure after i turn the key off like instantly but that is because no check valve on the pump and im using a in tank. base fuel pressure is at 38 in vacuum and doesnt run lean all the way up to 17psi
 
From the diaphragm? I also noticed the AN plug I used (provided by the FPR supplier) to plug the second input was very slightly fouling on the metal part of the diaphragm. I'm sure that would have caused issues if left unchecked.

I'm still leery of leaving this thing on here. Did you replace the Aeromotive with something else?

Yep. It started leaking fuel out of the reference pressure nipple.
 
Areomotive's older stuff used to be spot on. Great FPR.

Agreed. Have one on my Chevelle with EFI, and it's been rock solid without issues.

A 6 month old product certainly should have warranty service from AERO.... have you called them? I'm betting they will replace if you purchased new.
 
Mine looses residual pressure instantly also. Running an Aeromotive A1000 external pump with no check valve. Pressure on the gauge is rock steady at 42 psi when the car is running and my datalogs did not show any pressure drops that would've messed up my AFRs and injector's duty cycle.

What are the other options for a good adjustable FPR? What about this one from AEM:

http://www.aemelectronics.com/produ.../universal-adjustable-fuel-pressure-regulator
 
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Agreed. Have one on my Chevelle with EFI, and it's been rock solid without issues.

A 6 month old product certainly should have warranty service from AERO.... have you called them? I'm betting they will replace if you purchased new.

I have contacted the seller, so we'll see what happens.
 
watch out.. there are really much piracy knockoffs out there...

https://www.aeromotiveinc.com/buyer-beware-genuine-aeromotive/

Man, that's discouraging. People are literally the worst. A large bicycle company I once worked for had a guy whose full time job it was to track down counterfeit bikes. It's amazing how many there were.

In my case, my seller seems legit, and isn't on that list, for whatever that's worth. I also have the much less frequently ripped off model.
 
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