got a 93 sc quite a while back.It's an automatic with 373 gears (had a shift kit),118000 miles,stock engine.When i got the car it had no overdrive,but ran very strong.Over a period of a few months it began to gradually lose power but still had power and ran great.We rebuilt the trans with lots of goodies (2500 stall,mark 8 gears,aode overdrive etc..).Car was still down on power,changed fuel filter,tested pressure ok,changed plugs on passenger side(forget what they are but from sc perf.) and new magnacor wires,also did leak down test and ok.Still no power driveable though.Less and less power though over time.Finally got around to doing plugs and wires on drivers side,also plugged in vac line that was off of tube between maf and tb.Car ran like hell as if we crossed wires or something.double checked wires ok,unplugged vac line no difference.did not take time for leakdown on that side.Runs super rough at idle if it would idle.Oh also removed cats thinking they were choking it.No check eng light,and no bad codes at auto zone check.Any help would be appreciated. Thanks
93 sc losing power now barely runs
- Thread starter ccmcnabb
- Start date
I would doulble check your codes first it seems odd that you haven't thrown any codes and its idling rough with no power. 
First I would look at the DIS module and the coil pack, then move to your IAC and TPS. I'm sure someone else will chime in soon, that can offer more help than me.
First I would look at the DIS module and the coil pack, then move to your IAC and TPS. I'm sure someone else will chime in soon, that can offer more help than me.
David Neibert
SCCoA Admin
Sounds like your harmonic balancer. Take a look at the crank pulley with the motor running and see if it's wobbling any. Also check to see if the center bolt that holds the balancer onto the crank shaft is still there.
David
David
J
Joisey Jim
Guest
I'm just going thru a very similar experience with my '93 5-speed (205,000m) . Looks like the stock style balancer (second one) is wobbling (all bolts are secure) and that threw off the timing, so much that I went lean on one cylinder bank and burnt a valve. So now it's hard to keep it idling as it's so rough & only 10-12" vacuum. However, it does reach 20" of vacuum at 1500rpm before going over to boost. It all started with the CEL just flashing when shifting between 1st & 2nd. The code was 81 - "lean on right bank". Then it started to loose power over 40 mph and kept stalling. When I pulled the plugs and 02 sensor on the right side they were coated with white ash.