hello everyone,

hope someone can help me, a friend of mine is here in Holland with his XJ6 he parked it running, now it won't start.

Engine turns over and i checked the back of the fuel rail, there is fuel coming, the counter shows 200 RPM while starting (crank sensor).

i removed one of the Direct igntion coils and used a screwdriver to metal trick to see if i got a spark, how ever no spark.

Any idea's


Sorry for any typo's English isn't my primary langauge, just helping out a friend who wants to be hope before Christmas..

 

I would start by checking to see if you have 12v at the coil connectors. If not, check the wiring continuity of the ground signal from the coil back to the ECM.

If the wiring is good, then the ECM would be suspect.

 

Also, are you sure the CKPS is ok? Some people have experienced that the sensor is faulty even if they see 200rpm on the tacho. Although this does not make sense to me, it does seem to be an issue.

 

checked the voltage on the coils 12V on the white/pink wire.

the Crank sensor measures at 1.25 K Ohm

 

Spark is ignited by the ECM switching the ground signals. If you have an oscilloscope you can check the output from the ECM.

Assuming everything else is working, such as the fuel pump (you did say there was fuel at the rail) the ECM would be suspect. If you can get hold of or borrow a known good ECM, it would be a very quick and simple job to see if that is the problem.

 

Had some more time today,

Rechecked the fuel to be sure, pump runs and disconected the fuel line at the rail again, plenty coming.

also disconnected the ECM, and measured the CKPS from that end, and not measuring anything, White to 23 (black connector) is OK, but Orange to 26 nothing.

So going to run a wire outside of the harness see if it will start.

I'll let you know,

and thanks for all the advice Allan.

 

Same thing happened to me, the car was left running then turned off by itself. I found my answer here on this site, it was the ecu relay. All you have to do is open your hood, stand on the passenger side, remove the plastic cover that is over the windshield washer bottle and you will see three relays all in a row. the ecu relay is the one farthest from you, just swap it out with one of the other three and see if it works. Hope this helps.

 

Update-

Been out of the country for a couple of weeks, back now apparently the jaguar dint fix itself

i did some more measurements.

As i previously stated i got fuel on the fuel rail, how ever i don't have fuel in the cylinders the spark plugs were extremely dry, and i measured on the injector coils,
Got 12v but no ground.

Also no Spark, there's 12v on the coils only also no ground,

now i saw on the schematics the ECU provides the ground for both, so is my ECU defective, or is this some weird Alarm issue ??

Alarm sounds weird to be since the starter does turn over.

Any thoughts be helpful.

 

IF the car is equipped with a sunroof, I suggest you check the ecu connector for corrosion due to water ingress.

 

no sunroof, and ECU connectors are clean

 

You should have 12v at the injectors on both pins at all times except when they are firing. To fire them the ECM pulses the signal to ground. You can see this on a scope but probably not on a DVM as the pulse is less than 3 milliseconds at idle.

You should be able to put a stethoscope or a length of hose to the injectors and hear a rapid fire clicking when they are firing.

If they are not firing, then, as others have said it could be the ECM relay as it switches voltage to the high power side of the ECM and the injector coils. However, if you have 12v on pin 1 of each injector then the relay must be OK.

If you cannot hear the injectors firing and as you've said that you have 12v on both pins of the injector connectors, then I would suspect the security module. It sends a fueling inhibit signal to the ECM when the immobilizer is on. This would prohibit the injectors from firing. Trouble is that is an encoded digital signal so you can't check it without dealer level software.