qwiketz

Hi guys. I installed a new regulator a while back and I can visually see the pressure dropping after the key is turned off. How long should it take? It's taking probably 30 seconds to get to zero from 42. I'm starting to think I have an injector hanging open.

The car is running rich and I think it's time to check the ohms reading on my injectors and do the screwdriver test to see how the injectors sound.

Other than that, I think most of the other things are in order although I am going to pressure test my exhaust system this weekend and check it (the before and after temps) out with the heat gun.

Anyone run into this before? The injectors are the common black 60's. They're about 10 years old but haven't had the easiest of lives. Probably about 15k miles on them.

Heatmaker

Why did you swap out the stock FPR in the first place? Where you having fuel troubles before?

Might be to each their own but I never had any success when trying to install the Automotive FPR on my LT1. Made the car run rich and gave me fuel pressure problems.

qwiketz

I was having issues with the stock one not keeping up with my big fuel pump. I couldn't get the fuel pressure under 60 ish psi.

qwiketz

Not really a definitive answer here (from Brett below). On with the other tests...

Russ,

Aeromotive regulators employ a poppet design that’s optimized for performance with the engine running. They will not necessarily hold pressure for any length of time once the pump is off and there is no flow. This is not a sign of either a bad injector or a problem with the regulator.

Hope that helps, let us know if you need further assistance and thanks for choosing Aeromotive!

Brett Clow
Tech Director

Aeromotive, Inc.

Heatmaker

Have you tried the Metco adjustable FPR?

Puck

iTrader: (17)

Mine has always done the same thing. Never caused an issue.

Originally I thought it was the check valve in the fuel pump, but after changing the fuel pump years later it was still doing it. Mine doesn't even last 30 seconds, more like 15 before its zero again with key on/engine off.

Again though, this has never caused any issues and pressure is properly maintained while running.

qwiketz

Thanks for the input. At least now I know it's likely not an injector hanging open. I listened to all the injectors clicking today after work. Sounds like they are firing. Combined with this info I'm off to the next item on my list.

Heatmaker

If it wasn't running rich before and is running after the Aeromotive I would probably point to the areomotive. It's common for them to cause the LT-1 to run rich. There used to be a lot of complaints/threads about problems people ran into after installing them so they became a mod to avoid just like the yellow accel fuel injectors that caused similar issues. I'd be more worried about fuel getting into the oil so check there first to see just how bad the "rich" condition is if it's so bad that you think an injector might be stuck open. Try the cheap trouble shooting method and put the stocker back on and see if the "rich" condition leaves.

qwiketz

The regulator seems to be working fine other than not holding pressure after key off. I have a gauge on the rail and it seems to be holding the pressure fine.

My engine was rich and pressure wouldn't go below mid 50's prior to the change to the aeromotive.