[brantcaulley]

ok i have a good one that has me stumped.

the car is a 72 911 with mfi.

i have had the car for about 2 yrs driven very seldom and decided to do a tuneup.

i adjusted the valves and added:
new coil, cap, rotor, wires, fuel filter, oil change, points
and everything was fine.

then decided to put new sparkplugs in it.
it had bosch w3dpo in it.

i first bought ngk bp8es, installed them and the car ran terrible. backfiring really bad.
so, i figured wrong plugs and put the old ones in it and it ran back to normal.

the old plugs look so awful i tried again and got bosch w5dpo.
installed them and it runs terrible again.

so again i put the old w3dpo plugs back in it and now its back to normal.

so before i spend another 80 dollars on plugs can someone tell me what is going on ?? !!

the other weird thing was when i had the w5dpo in it i pulled all the passenger side wires off and the car stopped backfiring and idled fine just had no power.
but i plugged the passenger side in and unplugged the driver side bank and the car wouldnt run at all.

i did a compression check and had good compression on all 6 cylinders.

i also have a syncmeter and measured each cylinder while idling and the passenger side is between 7 and 8. the driver side is at 10 to 11. i adjusted the air screws on the passenger side but they made no change in the measurement.

anyone have any ideas whats going on??

thanks

brant