Discussion:
FGC20k rebuild...HELP!

I got this fgc20k with 4g63 engine from someone who was going to
Scrap it. He bought it for cheap and didn't know much about the history. I love a challenging project so now I have it. Here is what I've done.
Repaired radiator
New coolant hoses
New distributor cap and spark plug wires
Replaced regulator with new impco model J.
Replaced mixer diaphragm
New plugs

I've heard nightmares about the emissions system on this truck and the computer seemed shot so I
Bypassed this system. The computer primarily controls emissions system so it should run without it.

The throttle body is voltage controlled
So for Testing purposes I have it hooked up
To a DC power supply that allows me to open and close the throttle.

I've gotten it to run a few times for 5 seconds but that was with ether. My guess is that I'm either getting no
Fuel or the wrong mixture. Since I'm bypassing the computer, how do I get the Air/fuel mixture correct? The carb doesn't have any
Adjustment screws. Also, I can rig up a circuit to
Control that 12 volt throttle body with the accelerator pedal, but I'm wondering if there is a standard throttle body that I could use instead to avoid designing this circuit. If I need a different carb and throttle body, does anyone have a model number suggestioon that would work?

I did verify timing and also have fuel lock off solenoid now turned on with ignition since computer is now bypassed. Any suggestions on how to proceed would be awesome!!
  • Posted 18 Dec 2017 03:35
  • By Vilas
  • joined 18 Dec'17 - 1 message
  • Illinois, United States

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Engineering policy lead, Logistics UK
Regional manager - Eastern Canada, Associated Equipment Distributors
Vice president - IT & EP OEM parts, Big Joe Forklifts