Adjustable MAP sensor no start

[Craigwhite73]

I searched the world over and have found no love on this subject. I have a 1989 Cherokee (Renix) and it is a 4.6 stroker. I have a 99 intake, aftermarket header (E bay), polished and ported head (7120), throttle body is bored to 62 mm (1995 ZJ), and I am running Bosch 0280155712 injectors. The exhaust is 2.5 inches, and nothing crazy has been done with the ignition. All sensors have been replaced with new ones except the MAP sensor, and I am assuming it is original. Now to the problem I have built an adjustable MAP regulator based on GoJeep, WaterforGas designs, and it is on a DPST switch. With the switch on factory mode it starts fine, but runs lean and runs hot (radiator), as far as cooling I do have a three row radiator, high flow water pump, high flow thermostat, and two factory electric fans. When I switch it to the regulated it will not start, and any response will be greatly appreciated.

[rammit11]

hi, are you 100% positive that you have a full 12v with key on and in crank position feeding the switched position?

[Craigwhite73]

I actually ran a wire straight from the battery to the adjustable MAP sensor.