Msanders2

I have a 94 Factory 5 speed Sc300 246,000 miles, and I've searched the forum and tried everything I can think of to fix the car. Bought it from a guy after is developed this problem and he parked it for a year. It had blown capacitors in the ECU. So far I've tried 3 different ones, 2 were rebuilt ECUs. It has a rough idle, no power when driving, and white smoke from the exhaust. Here's what I've done so far.
-3 different ECUs (known good one, Tanin Rebuilt ecu, and locally rebuilt ecu)
-compression test 155-160 across the board
-all 6 injectors
-distributor
-2 different sets of spark plugs
-Drain the gas tank
-fuel filter
-maf
-fixed cracked intake boot
-plugged off P/s vacuum valve
-cleaned the throttle body
-De-catted (no catalytic converters)

Car is in time, and new distributor is advancing like it should but still getting white smoke and rough idle and absolutely no power when you drive it. I honestly can't think of anything else to do.

Returd

X2

White smoke equals head gasket. Stop driving and fix it soon or bigger troubles.

A quick check of the oil after the engine has run should reveal a murky emulsion confirming water into oil

Msanders2

Head gasket isn't blown. 155-160psi across the board, doesn't over heat, no coolant in the oil, no oil in the radiator.

Returd

is coolant level dropping?

supra9398

Valve stem seals are a possibility.