Hey guys, totally new to the LT platform. I'm boggled over the amount of discrepancy on fuel pump and control information on the webs/forums.
Here is the dilemma. I've swapped a low mile L83/6l80 into our 1978 Scout II. We are using a Howell harness and ECM. Everything is plug and play and really easy. Except when it comes to supplying fuel.
We started out with a Walbro GSS342 pump and ran it returnless. Had the inline pressure sensor up near the engine. FPCM is mounted on the firewall and plugged in. The tune is set to be controlled by the FPCM like
the original engine was in the truck. Would not start or run. Truck would run with injector cleaner being sprayed in the intake but that is it.
Reading online, we have the wrong fuel pump installed. This is where we swapped to an OEM pump from napa and made it work inside of the Scout tank by removing the pump from the assembly and installing it in the Scout
assembly. We also added a Aeromotive Fuel Pressure Regulator on the firewall and a return setup. We are getting a solid 72psi out of the regulator and still will not run unless we are spraying in the intake.
We have went over every connection and plug on the harness.
Yes there is an inline filter and it is new. All -6 hose on the system.
Does a new FPCM need to be programmed to the system or will it work correctly right off the shelf?
What would you recommend we do about fueling issues? I'm leaning on something not being right with it and I'm not against starting over with the fuel side completely.
Should the whole FPCM be tuned out? Or is it even a possibility?
All help is appreciated.