FiTech EFI Tuning Forum

Please or Register to create posts and topics.

Stumbling and backfiring

Hey everyone, this is my 1st post / question. I'm new to this so I appreciate your patience. I had a Fitech system installed on my '67 Chevelle a while back but am having some issues and the shop that did the install has closed down and there's no one in the area familiar with the system. The car starts and idles fine but when I accelerate too hard it stumbles and backfires thru the throttle body. When I'm driving down the road just coasting it will pop out of the rear exhaust. I sounds like it's running lean but I have no idea how or what to adjust. Computer stuff is out of my wheelhouse lol. It's a 350 crate pretty much stock. Any help would be really appreciated. Steve

When you accelerate too hard and  it stumbles and backfires thru the throttle body, is that from a stop or when you decelerate by letting off the gas pedal and hard re-accelerating? If that is the case it may be related to the DFCO setting in the handheld. To disable it, go to GO-EFI Tuning in the handheld and select FUEL CUT CONTROL. In the Fuel Cut Control section change Dfco Enable Temp to 300, so that Dfco never comes into play. That should fix that issue. If  DFCO is not the problem you maybe on the wrong cam setting ( try 2 if set to 1) in Go-EFI Initial Setup in the Engine setup or you need to increase acceleration pump settings or fast acceleration to increase fuel. Remember when ever you change a settings make sure to write it to the computer and key off to save changes.

Yes, that's exactly when it happens.  I'll give those a try. Thanks very much!