I run the same setup as you (with the exception of your plumbing) and have no problems. Not saying it's perfect or as good as running a 2-bar map, but you can get it real close and not have to worry about it. My motor runs 13ish at idle and around 11.8 WOT at 5lbs of boost. 8* base timing at 31* total under boost. Runs real good.

Speaking of MEFI controllers, MSD now offers a MEFI 4b with harness for $1200. I'll probably migrate to that next year.

http://www.msdfuelinjection.com/

Griswald
Thats good to hear. I have got a lot of info from everybody here. I think I just need to take a step back and look from the beginning. You ever head the K.I.S.S. theory? Keep It Simple Stupid. Most of the time this is the case something simple. I have a tendency to over complicate things.

From what you've described, I would replumb your fuel system to mimick mine, articfriends, and many others who use the Cartech FMU. Come out of the fuel pump to a dedicated regulator, take the return from that to the FMU, the output of the dedicated regulator to the rail, and plumb the return of the FMU back to a T at the inlet of the fuel pump. I can post some pics of my setup over the weekend if you like.

I have an adjustable regulator on the front of the fuel rail, so the output of that goes to the cartech. Fuel pressure does adjust from idle through atmospheric press and into boost. The difference is I run my return line out of the FMU back to the tanks not to a T before the pump and the adjustable regulator on the rail.

If this could be a major cause of my issue I will change it now. Is that adj reg on the rail a bad idea? I can just loop that end and install a new reg.

The output of the regulator, or the return of the regulator goes to the FMU?

Yes the adjustable reg is at the from of the rail. The return of the fuel rail them goes to the FMU. It is the stock location except that it is adjustable.

That's what I'm getting at. Lose the return from the rail and dead-head the fuel going into it. In theory, I guess it should work the same, but.......... you seem to be having problems dumping too much fuel the way it's plumbed. Might be worth the effort to try it the other way.

My .02 which are worth about 1/2 that in reality.

I never thought of dead heading the fuel into the rail. I just worked with the way it was through the rail. I can give this a shot as well thanks for the claification. Should I feed both sides or just plug the return end and feed from the original location?

Feed from the original inlet. What adj regulator are you using?

I forget the manufacturer of the reg it's just like the factory one but adjustable. The little reg on the front of the rail. If I redo the fuel system it will have to go and I will have to run one like Smitty uses, and I assume you do as well, and make a loop at the front of the rail. If you have a minute maybe you could give me a call 414-791-3115
Thanks
Jason