Fuel pressure 65??
Thread Starter
Teching In
Joined: Sep 2017
Posts: 34
Likes: 4
From: Edinboro, PA
Fuel pressure 65?? So I plumbed an electronic fuel pressure gauge into my C4-LQ4 swap and it is reading 65 psi. I have been chasing some issues with the call stumbling, hesitating, stalling, etc. I checked vacuum lines and that fix a lot of issues but same issues are there just less. I had installed a brand new Speedway fuel pressure regulator for 58psi. So I’m a bit perplexed as to why it’s so high.
TECH Resident
Joined: Jun 2011
Posts: 937
Likes: 472
Not sure why it'd be reading high (maybe your gauge), but also keep in mind the LQ4 ECU is setup based on vacuum biased system. So at idle, it would normally be even less than 58psi. If you're using the Corvette style regulator, that has no provision for connecting to the vacuum source. So you need to reconfigure the injector tables for a returnless system.
