2G Not running correctly

[Eric J Wandall]

I am having a slight missing issue with my 420A. I have completely rebuilt the Engine, Everything is new from top to bottom, even every sensor is new. I have the Timing set perfectly. At first it was running rich then I found a cut plug wire and replaced them. It ran fine for a couple of days then it through a P0123 Code So i Replaced the Tps sensor now there is no codes but it has a slight miss at idle and when I turn on the A/C it gets worse. Anyone have any ideas what it can be.

 

[stolenracer]

I haven't owned a 420a in over 6 years so please bear with me here. That said basic car knowledge still applies.

Things to check
spark plugs
Spark plug wires
Coil pack
Fuel injectors
Ignition control module
Any vacuum lines
Camshaft/crank shaft sensors
Wiring for any continuity breaks

This is just a basic list but might give some ideas. I would check to make sure all plugs are firing and at the right order. Also make sure your injectors are firing. A bad enough vacuum leak could cause it. If all the above come back good check compression.