91 stealth TT. Car hasn't run for over a year when I bought it recently. So far I have replaced the fuel pump, installed a rebuilt ecu, installed a used cas, & power transistor, and got the car running again. It ran good for a short while, (a couple of minutes), then started missing and check engine light comes on. Upon checking, I determined it wasn't firing cylinders 3/6, so I replaced the coil pack with another used one. Again, when first started, it will run good, then begin missing again w/the check engine light. I checked for codes and came up with code 53. Thinking maybe the plugs were fouling, I just replaced all of them. Again when I first start it, it runs great for about 1 minute or so, then begins missing again and check engine light comes on. Checked the codes again, still getting code 53. Pulled the #3 plug wire, stuck a screwdriver into the end of it and started the car again. It's arcing like crazy, so I plugged it back onto #3 plug and it runs good for a short time and then begins missing again. I pull the plug wire back off while it's running and this time no fire at all coming from the coil. Using a extra plug wire to ground, I check to see if there is any fire coming from the coil going to #6 plug, nope, nada. It appears, when the car is first started and it's in open loop, the 3/6 coil is firing, but I'm thinking that when the system goes into closed loop, the coil for some reason is dropped out.

Since then, (yesterday) I've again swapped out the cas, power transistor, and changed the 3/6 coil. The car started and idled fine for just over 6 minutes, then lost power to the 3/6 coil again. I can let it set for a while, start it back up and it will run on all six for a minute or two, sometimes a little longer, then the 3/6 coil quits firing again and the check engine light comes on. The only code I am getting is 53.

I'm lost here, does anyone have any advice/suggestions on where to look to resolve this problem? Any help would be greatly appreciated

Thanks in advance,

 

that rebuilt ecu might not be working right, do you have another one to test?

 

CHECK CRANK AND CAM SENSORS ,IF ecu isnt getting THE INFO IN NEEDS

IT COULD BE THINKING IT ALREADY FIRED THEM FOR SOME REASON BUT IT POINTS TO ECU PROBLEMS ,

 

Better check your ECU or sensors...