picked up a 92 RS for free the other day. car had no power, and i discovered the timing bypass was disconnected. plugged it back in and now it runs like crap and starts revving up and down and then stalls at idle. i put a timing light on it and it was bouncing all over the place. so i pull the ESC bypass wire again, and it stabilizes and runs smooth.

i have replaced the ESC Module and also the ICM. and i just ordered a new knock sensor. is there anything else besides those three components that could cause this problem? also found a lot of other problems with this car. turns out that free isn't always a good thing.

 

The wire is supposed to be disconnected when you set the "base" timing with the distributor. Do you know where it was set to? The timing can move around after you reconnect the wire, but it shouldn't "bounce" around.

Is the check engine light coming on? I'm guessing it is. If so, check what codes the computer has stored. https://www.thirdgen.org/service-eng...ht-error-codes

That's a good place to start looking.

 

Need to check and set timing with a timing light first . Then turn off car , plug est wire back In and then start car. Then turn car off and clear the est code 42 by disconnectin neg battery cable for a couple of minutes

 

You could have a bad coil, bad distributer , bad ignition module etc

 

timing was checked with bypass wire unplugged. timing is set right and engine runs smooth. when wire is plugged back in, timing starts jumping around and engine stalls. replaced coil, EST, and ignition module already. ordered a new knock sensor to see if that fixes the problem. also noticed i have a few things unplugged. missing the air temp sensor because the air filter housing is aftermarket. also found a wire hanging on the passenger side behind the block, but can't tell what goes there. it comes out of the main big harness, but is too short to reach the top of the block or anywhere under the headers. it's a two wire connector with blue and either tan or white .