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Well I've been having some quirky issues for several months with my NA 20b project. Most of these quirks have been fixed making the my car much reliable on a dailey basis however, some A/F related quirks still remain. So recently I installed a new AEM A/F wideband and gauge to replace the shitty Innovate unit I had. The AEM unit doesn't need calibration (which is a huge plus). Anyways, I quickly noticed that my A/F readings were different than before so I decided to retune. Well after looking at my fuel pressure gauge, I notice my pressure was down to 30psi??? I was like WTF??? Base pressre use to be 39psi. So I tried to raise the pressure but it wouldn't raise. Now I'm in full diag mode. I decided to go ahead and replace my fuel filter. The old filter wasn't really dirty but oh well. Tried to raise the pressure again and it still wouldn't raise. Next I swaped out the pressure gauge itself to make sure it wasn't getting stuck. Now the pressure is finally showing and increase when I raise it. Well as soon as I got close to 39psi, I started seeing fuel come out of the vacuum nipple of the regulator. So I disassemble the regulator and this is what I find. Keep in mind that this is an Aeromotive regulator I bought brand new back in 2009 and only has 5,000 miles on it.
As you can see, the internal diaphragm had ripped and was leaking fuel out of my vaccum nipple. This virtually makes adjustability impossible. Plus you run the risk of the pressure NOT raising under boost.
So you guys may want to pull yours apart for inspection.
Wow, this happen to me about 5-6 years ago with my Aeromotive FPR.
The car started sputtering on boost at the track.
Had no clue why, so I took it to Chris at Rotary Performance.
He nail it after a while and it looked exactly like that.
The diaphragm was collapsed.
Makes me wonder, could it have been a bad batch of them???
my car has been having a cold start issue, car felt like it was running on 1 rotor but then i realized it was flooding out on one rotor by the sounds of it. so i check my fuel system and here a hiss that wasnt there before when i prime the fuel system. the pressure also drops immediately after i take off the jumper to prime.
my fuel lab fpr seems to be the cause. the hiss is definitely inside of the fpr. now i get to take it apart and inspect whats going on. thanks t-von, hadnt considered this while brainstorming.
edit. i checked my diaphragm and its just fine. my next educated guess is a leaky primary injector.
This is why having the ability of a modern ECU is so important. Using a modern ECU along with a FPS would allow it to monitor the fuel pressure and alert you to pending danger. If this was a boosted car the motor would most likely be junk.
This is why having the ability of a modern ECU is so important. Using a modern ECU along with a FPS would allow it to monitor the fuel pressure and alert you to pending danger. If this was a boosted car the motor would most likely be junk.
Your 100% right as I currently don't have any of these types of feedbacks going to the ecu. I'm planning in upgrading to the Haltech Elite (as soon as all the rotary related features are fully functional) sometime next year.
This picture shows how the non--barbed (Aeromotive has sharp backed barb) reference nipple and supplied plug mark this particular unit as a fake. There are MANY different counterfeits of this regulator though.
"The genuine Aeromotive fuel regulator has stainless steel screws, brass vacuum port barb fittings and a brass gauge-port fitting. You can easily test for brass and stainless fittings with a magnet."
09-05-15, 03:16 PM
I decided to go ahead and replace my fuel filter. The old filter wasn't really dirty but oh well. Tried to raise the pressure again and it still wouldn't raise. Next I swaped out the pressure gauge itself to make sure it wasn't getting stuck. Now the pressure is finally showing and increase when I raise it. Well as soon as I got close to 39psi, I started seeing fuel come out of the vacuum nipple of the regulator. So I disassemble the regulator and this is what I find. Keep in mind that this is an Aeromotive regulator I bought brand new back in 2009 and only has 5,000 miles on it. 
