my car died while driving on monday. it sputtered like i ran out of fuel. i had been on the same tank for only 2 days, and have over half a tank left. i had it towed back to work to take a look.

my first thought was the fuel pump. i got it on a lift and checked pressure. ive got 45psi. i checked the injectors, and they are all pulsing fine. so, in theory i have fuel... i also changed the filter to be safe.

i changed the plugs and wires. the cap and rotor are only a year and a half old, but i checked it anyways, and its all good. i have plenty of spark.

checked compression... after trying to start so many times, i washed the rings, so compression was only 80psi at best. i put some oil down the plug hole to get the rings back up. rechecked compression and im now at about 150-160 across the board.

still wont start!

rechecked the CEL codes, as last time, there were none. now i have code 12 for the RPM signal.

im thinking the crank sensor took a crap. any ideas?

does anyone know where the hell the crank sensor is? i called the lexus dealer, but they said their too busy.

its a shame all of us BMW tachs are so spoiled with the bimmers... it makes it hard to diagnoss the SC in a timely manner.

thanks for the help.

 

ok, the dealer called back and said there is no crank sensor on the car.

the tech over there said the distributor is where the computer gets its RPM signal.

i have a hard time beliving thats the only place seince there are two codes for RPM signal... 12 and 13. i have code 12.

he said he would call back when he finds out where to look for code 12. damn this waiting game... but im not going to spend $125 just for them to look at it and recheck everything ive already checked.

does anyone know which wire from the 4 on the connector for the distributor is the one for RPM signal? i dont have access to any manuals or pin locations.

thanks.

 

its probably the wire your alarm is spliced into... check the connection of that. told ya that alarm was f'in up your car...

 

nope, thats been dissconnected. im thinking the code was actually from spinning the motor over with all the plugs and wires removed and the distributor connector off while i was checking the compression.

honetsly, the only thing left that still makes sence is bad gas... ill have to get a sample on monday.

p.s.- im taking your car to josh's party

 

for the record, a new distributor fixed it.

SHE'S BACK!!!!!!!!!!!!!!

anytime you see code 12 on a pre 96 SC300, it has to be the distributor... there is no crank or cam sensor.

 

good to hear you got it fixed. nothing more troubling than a problem that is hard to diagnose.

 

You guessed right! There are three separate pickup coils in the distributor which measure RPM and crankshaft angle. if any one of these sensors malfunctions, or a shorted wire between there and the ECU, you'll get the code 12. Most likely you could have just isolated the particular sensor, but a whole new distributor would surely do the trick! Good call

 

i wasnt happy about spending $230 at lexus for a new one... (at my cost), but i had a friend with a used one for $20, so that made it easy.

p.s. phil, did you come back to CL just to help me out? where he hell have you been hiding? hows the SC?

 

I'm having this exact problem on my SC400. Is there anyway to test the dist?

 

did you every find out what the problem was...I'm having the same issue with my sc300.>>>. Let me know if you can help..

 

Check post #5 he said a new distributor fixed it.

 

are you throwing codes?

i had the same problem with mine only difference was i was throwing a code 13 rpm signal instead of a 12.

Turned out to be a loose plug on my cam sensor.

Check your cam and crank sensors on the 400 as they do have both cam and crank sensor.

 

I'm throwing a code 12 on a 95 300. I read here that pre 96's don't have cam and crank sensors. I was wondering if anyone found out what sensor in the distributor was bad, rather than replace the distributor itself. I did see where the clip on the coil wire where it connects to the distributor was broken and the plug was loose. The coil plug looked a little rusty, so I ordered
a new one. But the clip and the wire will not be here for a week. Was just wondering if anyone had more specific info...thanks.

 

Can anyone provide more info on which senor in the distributor is the problem when the engine cuts out after starting and throws a code 12....?
It would be much appreciated..thanks.

 

92-97 SC300 gets the crank and cam signal from the distributor so i would replace the distributor and go from there.