Welcome to Modern Mopar Forum

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more! This message will be removed once you have signed in.

Blue Blur

Walbro Gss340 Pump Enough For Stroker 6.1??

My car is a home built hot rod and when I first built the fuel system it was a mild BB with FAST EZ EFI and I installed an in tank Walbro 255LPH pump. The FAST ran with 43 psi with a regulator and worked good in that combo. I now have the stroked Gen III and use an LS filter/regulator which are typically 58psi. My injectors are 80lb Dekas, I know way bigger than needed, and it has worked fine until recently I have been seeing some lean shutdown from the ECU, which is a good thing that it shuts engine down from a lean condition, and its will sometimes backfire between 1st and 2nd shifts then intermittently lean out then as well like the pump shuts off then turns back on. Thinking about swapping to a Walbro 450 and also monitior fuel psi better. Havent been able to read data logs, and haven't been able to get it to act up when datalogging either with MS3 EFI. That's on me and I will get that figured out, probably need to get a memory card installed and do it that way.

Share this post


Link to post
Share on other sites

You sure the pickup is staying submerged under acceleration? We run a stock 5.7 pump (280lph), factory regulator and factory 5/16 line and a 60 lb injector in the 440 and make a little over 600 at the tire running ms109 which is a much leaner burning fuel. We are consistent on A/F with no signs of pressure drop.

Share this post


Link to post
Share on other sites

One thing I did change is I ran the return line to the surge tank instead of at the front of the tank where it was originally. Pump is in a surge tank with trap doors at rear of tank. I wonder if return line routing is causing aeration possibly? Have also read the relay setup that comes in the Efisource kit is iffy. Next step is mount relay at rear close to pump sttaight off battery. Seems like temp effects it as well. Really dont think its a fuel starvation problem since it always happens under acceleration high load and the tank is always half full or better.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now