I guess I'll begin saying what lead up to this problem. I have a 1988 XJ6, seemed to have some problems with the car idling correctly. After checking the plugs I realized that the spark plug oil seals in the valve cover gasket was leaking, so I replaced the valve cover gasket and plug oil seals. After getting all the oil out that was down around the spark plugs (which took some time) and getting everything cleaned out good, I installed new spark plugs and put everything back together, the only thing I removed other than the valve cover, gasket and cover bolts was the pcv valve house from the valve cover.

After getting everything back together (and charging the battery) which I just bought this year, the car wouldn't start. I figured it was either not getting gas or not getting spark. I pulled a plug and as I expected NO SPARK! It turns over great just no spark.

I removed the rotor cover and checked it and the rotor out, looked good. I checked that the amplifier was getting voltage from the battery with the key on, 12.50 looked good, I checked that the coil was getting voltage, looked good, checked the coil resistance, looked good.

It seems I'm not getting high voltage out of the coil going to the rotor. I dont understand, because everything seemed to check out ok. I know I'm not getting anything from the coil to the rotor, I can grab hold of the coil wire end when the engine is being cranked and not even the slightest of voltage.

I replaced the coil with a known good one, I replaced the amplifier with a known good one replaced the coil wire with a known good one. I'm at a loss on why the coil isn't putting out voltage, I wasnt sure which relay under the passenger dash was the ignition relay so I switched relays around with other ones under there (they were all the same type of relay except one that I didnt change, which I believe is the starter relay.)

I can't think of anything else it could be. I'm guessing that from the oil around the plugs causing the spark to jump to the inside of the plug tube holes must have damaged something in the ignition system, I don't know what else to check. like I said the problem is before the coil, so this rules out spark plugs, wires rotor, rotor cap and coil wire.

What would be causing that coil to not produce voltage when I know the coil is good and I know I'm getting voltage from the battery to it, I checked both secondary posts and I get voltage on both sides with the key on.

Thanks

 

Here goes again, first post blew up...

Your engine has a crankshaft sensor, located on the timing cover down low in front, and pointing at the crankshaft dampener. When the engine is cranked via the ignition switch, the crankshaft sensor generates a signal that the Electronic Control Unit needs to time the ignition system and fuel injector operation. No crank sensor signal= no spark and no injector click.

Follow the wiring lead up from the sensor, it has a round black connector at the front of the cylinder head, beneath the upper radiator hose. It is possible that this connector was disturbed when you replaced the cam cover gasket. Check and clean this connector, there is a slim chance that will do the trick. More likely is that the sensor has failed, which is a common occurrence. PM me if you need more info or a new sensor.

Normally I check for spark, listen for injector operation with a stethoscope, replace the crank sensor if I have neither, and road test the car because it is now running just fine.

 

For the most part, I agree with JTO. Except, just replace the crank sensor and keep the stethoscope for the wife. You'll get a lot more out of it.

 

Does that give you a heart-on?

 

Yep, thats what it was. It was the only thing left to troubleshoot. Thanks guys.