rhubarb999

93 SC300 5MT - 152K - has run perfectly for years.

Yesterday morning I started the car for the first time in a few weeks. I was on my way to the A/C place to get the system filled.

Car started and ran fine. About 5 miles down the road I realize that I have no power when I put my fott into it. At first it feels like the clutch is slipping, but the tach is not rising so the clutch is fine.

I turn around, drive and pull into the garage. As it idles, it is shaking and there is a loud knocking from the engine, 3 in a row then a slight pause, and three more. I smell of fuel in the exhaust.

I left it alone and went to start it this morning. First couple of cranks it died right away. Finally got it to start but I have to keep the gas down to keep it running. No knocking, but it does not sound smooth. No CEL.

It finally idles on its own, but it is very low (headlights are dimming). It stumbles when I step on the gas. When I let off, it almost stalls, then recovers and idles low. Again there is a very strong exhaust smell.

I did a quick check of the plug wires at the cap and they are tight. Where else should I look? Last time I drove it, it ran perfectly ... very frustrating.

Thanks

rogers2014

this is happening to my car, 93 sc400.... the tps sensor, and the maf sensor were having trouble and my car does the same thing, check your maf sensor and your tps sensor, i'm replacing my tps sensor soon as i believe this is the problem!! hope it helps the tps sensor is on the throttle body the maf sensor is on the intake...hope this helps i'm sure your car is similar to the sc4 just different engines, also check for vaccum leaks my sc4 has a few i'm going to get some new hoses all this is a contributing factor!! hope this helps

clydes93

Kinda sounds like a bad coil.....make sure it has a good solid blue spark

rhubarb999

Is there any way of testing these before replacement? I hate to buy parts that don't actually fix the problem.

YeA 2jZ

iTrader: (15)

Sounds like ecu

Ali SC3

iTrader: (10)

same thing happened to me, the coil was fine, but the rotor in the distributor was worn down.
coil is a much less common problem on the sc300, since you have 1 if it was bad you would get no spark at all.
usually its the rotor inside. replace rotor and cap with toyota parts and retry.

rhubarb999

I'll pull the cap tonight. Thanks

chingpo05

iTrader: (2)

pull the parts and look for obvious wear and burn marks. check plugs for major discoloration (will be pitch black if fuel wouldnt burn due to ignition system) but what you are describing as "knocking" kind of scares me be nothing should be knocking from the motor