i switch from a b&m to a aem regulator and now my fuel will not hold pressure after i prime or when the car is turn off. the b&m hold pressure. i replace the aem with a new diapham and still no pressure. is this normal for aem pressure regulator?? i always have to prime the car a couple times before it can start

 

aem is garbage period ... dont believe monitor your fuel presure between 6-9 k watch that presure drop and come back at higher rpms

 

Sounds like the aem isnt holding pressure, are you adjusting it far enough down to get the desired pressure? Is it just the initial couple turns of the key that it takes tog et pressure after the install or is it all the time?

 

I had/have one. Was brand new...loaned it to a good friend,it was on a GSR for 3 days, then went back into the box for a couple months, when I put it on my car it poured fuel from the connection of the two halfs..... Aeromotive FTW!

 

what fuel pump is on the car? Walbro's dont have check valves like oem fuel pumps do so they wont hold pressure when the car/ pump isnt running.

 

Pressure is at 55psi on idle. I have to prime a couple times and start the engine while in prime mode. If not the pressure will drop to 0 after the prime stop. It may hold the pressure for a second while it's fallling to 0.

 

I've had two of them and they've been flawless. AEM did redesign the diaphragm and orifice from a flat surface to a ball. Open yours up, and if the diaphragm doesn't look like the attached picture, buy a rebuild kit and upgrade. If not, try the smallest size orifice. There should be 3. Either way, it's normal to have to start right after priming. It's not going to hold pressure in the line like a stock FPR when the engine isn't running.

 

I bought that same kit and mine was the same
As the kit. I still went ahead and replace the diaphragm and still same thing. I have the black orifice on. I have try the larger orifice and still don't hold pressure. At yours holding pressure??

 

It holds pressure fine when the car is running, but it drops faster than stock with the car off. It's normal.

 

i have the black orifice on. is this the correct one to use? i have a 255 walbro
will changing to a larger orifice change affect a tune?

 

i have a 255 walbro. with the b&m fuel regulator it hold pressure for a while when the engine is turn off or with one prime from the pump.

 

The black one is the smallest. That's what you start with. The only reason you'd need to switch to a larger orifice is if you're unable to lower the pressure at idle when you're adjusting it.

Honestly, I don't see why it would bother you that the pressure drops when the car is turned off. It's normal.

 

Honestly, I don't see why it would bother you that the pressure drops when the car is turned off. It's normal.[/QUOTE]

Because with the b&m or stock regulator it will hold pressure and I will able to start the car on the first try. With the aem it will take me 2 to 3 times until it starts.

 

This happens to mine as well, as well as others, i've found this to be fairly common with AEM FPRs. If you prime the car it will drop, but once you start to crank the car it goes back up and holds fine will driving or WOT. If you just turn the key, and let it sit, it will drain back to 0. Its a fairly common thing.

 

My Weldon regulator does this. As soon as it primes the pressure falls to zero within seconds. But its fine once the engine and pump(s) are running.

 

Mine does the samething. Still works like a champ.

 

It's not a concern as long as it holds fuel pressure especially under boost... I never had any issues with the AEM FPR (both the bolt-on units or the universal), until really high boost (30+ PSI).

Beyond that, I ended up switching to a Turbosmart regulator and it held better than the AEM.