96 XJ won't start

2.5L, Manual Transmission

XJ wouldn't start after sitting overnight, and I've reached the point where I'm stumped.

I tried pulling the air cleaner hose of the throttle body, still wouldn't start and didn't observe any obstructions.

Today I put a timing light on the secondary wire front the coil to the distributor--no flashes. I pulled the coil and resistance tested fine. There were 2 cracks in the housing, but I think the coil is good.

I hooked the meter up from the power pin on the coil connector (not the one from the pcm) to the ground on the firewall, and the meter read amperage upon cranking.

I then got a test light and hooked it between the two pins in the coil connector, and the bulb didn't light when I cranked the engine. Does this point to a bad pcm? I've also played relay shuffle, and the presence of power to the coil when the pcm is out of the circuit makes a bad relay seem unlikely.

Check your CPS - I believe a bad CPS will cause a "cranks but no spark" symptom set.

You have confirmed no spark? In other words, your timing light works?

Try connecting/disconnecting the CKP/CPS crankshaft position sensor a few times.

How was the weather last night?

When was the last time you cleaned the grounds?

I checked the crank position sensor and got the correct open circuit between terminals b and c. I can't run through the procedure for the cam sensor because I only have a digital meter.

I need to wait until the weekend to have a running car to check the light against, but the test light hookup I did suggests to me that there is a problem sinking the ground from the primary. Or does the pcm need to see a certain resistance to sink the current properly?

I suppose cleaning the grounds is one of those if you can't remember the last time it's time to do it again sort of jobs--I'll give that a shot next time I go out and wrench on it.

The weather over the night it died was probably 50-55 degrees, which was colder than it had been, but not that cold.

CPS, mine died on me while driving about 55MpH on the highway.

It's a common problem.

I checked the timing light with my brother's jeep, and it works. I have a crank position sensor in the mail, so I'll try that next.

Crank position sensor it is.