69MustangCoupe393cid

Hey guys I'm still chasing my fuel problem with my new setup and can't figure out what's going on. The thread below was the start of it and the last couple posts kind of show where I'm at because this is driving me insane.

https://mustangforums.com/forum/4-6l...id-inside.html

Every time I let off the gas and get back on it fast I get a hesitation. Based on the fuel pressure dropping to 25 psi after I let off the gas when idle is 30, I feel like this is my problem but I cannot figure out what can be causing this.

I don't think it's tune related because this engine was fine in the car it came from and I'm running that same dyno tune with the same setup. Also I have changed my fuel pressure sensor and my fuel pressure regulator as well as dropped my fuel tank to check for a lose hose. Fuel filter is new and pump only has 10k miles on it from what I've been told. The car drives fine otherwise. Any ideas?

69MustangCoupe393cid

Bump. No body? Is this that weird of a problem? Does anyone know anything else I can test? I was thinking fuel pump driving but now I'm not sure my car even has one.

mia96gts

Change the pump!! Who cares how many miles it has.

69MustangCoupe393cid

The pump makes pressure though, something seems like it's commanding it off, hence why it drops off between shifts. Could a bad pump really make that happen?

uberstang1

There technically isn't a fuel pump relay its paert of the CCRM, but it could cause issues

69MustangCoupe393cid

The CCRM? Because with my old motor it ran fine, once I got this new setup I started having issues. That's not to say something fried somehow, but odds are it's something I added that is causing this issue and I just don't know where or how to troubleshoot this without spending a boatload of money replacing everything.