2003 Lexus LS430 3UZ-FE crank no-start no-spark

Hi everyone, I have a crank no-start no spark condition on a COP ignition system. I have verified engine RPM with scan data and I visually checked timing marks at the cams after removing the covers. That inspection may not have been necessary, but I was curious because the previous shop did put on a timing belt. After this I checked my ignition coils for power and ground, they all have both. I put a known good ignition coil on from another car and the known good coil gave me spark on all cylinder that I tested one by one. Could all of the ignition coils be bad? What other tests would you do? Also, when I went to pull the car into the shop it did start and ran with misfires. Once a load was put the engine from a small incline the engine stalled and has not started since. Thanks everyone!

JeepLife wrote: I put a known good ignition coil on from another car and the known good coil gave me spark on all cylinder that I tested one by one. Could all of the ignition coils be bad?

If you consistently get spark with a know good coil, and consistently FAIL to get spark with all the others...I would say it is possible.

What other tests would you do?

It looks like the Cam and Crank sensors are Variable Reluctance Sensors. This means that they put out an AC sinewave, and the air gaps between sensors an reluctors are very important. Sometimes, they are adjustable. I would check that. You have RPM signal, which means there is a signal there, but if the air gap is too wide, amplitude of the signal will be low.

Thanks fellas. I did check the crank sensor reluctor ring and sensor gap visually. it appeared to be ok, so I checked that off the list. Ended up finding very low compression on most cylinders. Once talking with the customer he did say it overheated and was giving him trouble, thats why the t-belt and radiator was replaced before I got it. Customer declined the engine replacement, but Im still wondering about the inconsistent spark.