Re: new version of mpi kit

My MPFI kit from Hesco is four years old, and I have a single rail injector system.

Come to think of it, This MPI kit is also modeled after an 94 Wrangler. How could they discontinue these parts? If you need replacement parts you only need request the same from a 94 wrangler, correct?

DC didn't discontinue the parts, the supplier of the 1994 style intake manifolds is apparently in receivership and no longer supplying them to DC. That is the reason for the "design change," which uses a manifold and fuel rail from later years rather than the 1994 YJ, and which are manufactured by a different supplier. Due to this "design change" to later year parts, DC must obtain a new "EO" number to make the kit smog legal in California.

Some of the old style kits are still available (at least until dealer inventory is exhausted), but very hard to find.

Robert Bills KG6LMV Orange County CA

Sure they do. Jeeps have had no return line on the fuel rail since about '95. Regulator is in the fuel pump module.

My guess would be "poorly" :)

That's easy Will, just unplug the feed line where it connects to the rail. The gas will come out after the pump runs for a few seconds.

Oh, it's straight forward. On the older versions all you do is open the Schraeder valve until you get flow and all that leaves is a tiny amount that will clear thru the by-pass - but it does take a while. If there is NO Schrader valve and you pull the input end you still have aair filled rail until the air is purged thru the injectors. I don't know about the Jeep but that can be really problematic on GM V6 fuel rails - BTDT.

Whole concept doesn't make good engineering sense to me so it must be abean counter thing...

Could very well be. It may also be better than sending heated fuel back to the tank if you're trying to control evaporative emissions.