This is for a 1993 T100 and I posted in the T100 forum without any response so I thought I would try here. My T100 will start with difficulty and idles but barely. HOWEVER, if I connect a battery charger to the battery the truck starts much easier and and idles just fine. I have checked the battery and tried a different but same results. I also had the alternator checked and it passed with no issues, checked it three times just to make sure. Used propane to check for vacuum leaks and found none. I replaced distributor cap and rotor because they really needed it but no performance change. I put in a new fuel pump approximately 18 months ago. EFI relay checks ok and have jumped across Fp and B+ but the same results. The truck acts like it isn't getting enough fuel but I am hesitant to drop the tank again without some input. I have not checked the circuit opening relay yet. This just started happening after the truck sat unused for a couple of months. The strange thing to me is that it runs so well when I connect a battery charger. Thanks in Advance.

 

I was thinking MAF but the starter comment makes me think not... Even if the alternator is good could it be the connections (ground wires?) The battery charger is adding more "juice" to the system making it work? Somehow the regular power is not enough for the spark plugs?

 

maybe but I'll keep trying. And I'll update if I ever figure it out.