Crankshaft position sensor diagnosis?

[jdm_master_X]

Hello everybody.

First time really working on a Q45. The shop resources here suck (ALLDATA Pro), and it does not really specify much for the car.

Initially, the other technician who works with me was doing a valve cover gasket on both banks. He undid the air cleaner, throttle body, and some hoses and wires, including the CKP. He put it all back together as is, and now the car has a hard time starting. Just as if it were choking.

So I took a look and figured the plugs were fouled because during removal some coolant entered cylinder 3 (from the coolant line on the throttle body). I cleaned the plugs of fuel and coolant. We put everything back together and it still refuses to run. It cannot even hold idle.

The Snap On scanner pulled out the code for "No signal from crankshaft position sensor". That is telling me it either has an open circuit.

My other thought was maybe the sensor was moved a bit and lost its timing (because it happened to my SR once).

When the motor starts, it chugs and dies. It sounds nasty.

Anyway, your help is greatly appreciated. We just need to get this car out of our shop!

Thanks, guys!

[burijon]

You can find the factory service manuals with the link provided. Not all years are listed but it is a good start and handy to have at your disposal.

http://www.phatg20.net/modules...id=62

[Q45tech]

The CAS has 3 separate signals one to crank one to run and a emergency backup.

Depending on year you have [2 connectors on 90-93] and a single connector on 94-96......................check the connections.

After that it gets complicated as you must tap the 3 signal wires and look at the waveforms [for drop outs] with a digital oscilloscope.

[jdm_master_X]

okay i figured out the problem.

there was coolant in the connector and it was shorting itself out trying to start. after cleaning it out, it ran excellent.

thanks for the help!