Powerjection 3 on a windsor 302

[AdynPeplow]

Hi guys i am new to ffcars.com, been reading alot of the threads and thought what a better time to join then now, when i have a problem..

A week ago i installed a powerjection 3 unit onto my 302windsor, thinking it was going to be easy, well.... After the initial install and wiring which was easy i went to start and nothing, crank but no fire, no prime, nothing!, i then played with the plug (Main harness) and the fuel pump kicked in and primed the system to 45psi, i then further tuned the stage 3 dash settings to suit my engine and proceeded to start the car, cranked and it fired and ran. the car then shut down 2-3 minutes later probably due to my computer losing connectivity to the unit. and would not connect then it would then it wouldn't then it would, then it would drop out and connect back up.The next day i went and tried again, key to ignition, i had power going to the plug from both battery 12v and ignition 12v, but no fuel pump priming or connectivity to the unit, i then decided to change the crappy harness connector they supply and replace with another plug, but still nothing , this system is brand new, hasn't even got 10 minutes on it, and i have problems already, My wiring goes like this :12v battery is connected to the alternator, my ignition source is connected after my immobilizer, i am running the black wire to the negative off my coil and the fuel pump to the fuel pump. I check the earth off the engine and it is around 11.80v around the whole block, and off the powerjection unit, I am just wondering if anybody else has any problems like this or has any advice to where to go from now?? does the unit need a perfect 12v to operate? i am so close to hearing this thing roar, but seem to be running into problem after problem, there are no diagrams in the instruction
Any help would be good help thank you in advanced, should i run the 12v straight from the battery instead of alternator, or is 12v from the alternator good enough,??

[twan374]

Try taking your power directly from the battery. Although there is the same 12 volts at the alt output When the alternator starts charging there is a fluctuation in the output at that point. The battery acts like a shock absorber when it is charging and the voltage is "cleaner". Most computers like steady clean voltage. the alternator may be playing a part in your troubles. Also a fully charged battery should be about 12.5 volts. 13 to 14 when the alternator is charging it.

[AdynPeplow]

Yes i wondering if the powerjection system was sensitive to the 12v, i thought that the computer would still connect to the ecu, tonight i might run a extra wire from the spare battery to the 12v in as well as the alternator, maybe my batterys are just low, i have been starting alot and turning on and off performing checks, ill run a extra wire and let you guys know how i go