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2001 XJ Sport 4.0 Crank no start Think I made it worse

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Old 10-31-2020, 05:06 PM
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Default 2001 XJ Sport 4.0 Crank no start Think I made it worse

Good Afternoon Hive!

I have searched the forum a bit and ran through a lot of checks. This is where I stand.

2001 XJ Sport 4.0L My Nieces Car.

Goes to grocery store comes out car cranks, no start.

In my garage now. Cranks, no start. I can hear fuel pump prime. Fuel at Schrader valve on fuel rail. I used Starter fluid in throttle body while cranking, not even a stumble.

Screams no spark.

Replaced CPS no joy

Tested coil packs, got a fault in 3,4 coil, replaced coil packs, no joy

Checked all fuzes & Relays no joy

Swapped a PCM from my 2000 XJ, no joy.

Here is the fun part, swapped PCM into my 2000 XJ, starts & Dies after 3 seconds (SKIMS right??) but looks like PCM out of 2001 XJ is not the no start issue.

Put original PCM back into my 2000 XJ, Starts & Dies after 3 seconds. I appear to have killed the SKIMS coding in the PCM?

So I now have 2 non running XJ's in my driveway......

ANY insight into EITHER XJ issue would be HUGE!!!!!

Old 11-01-2020, 05:40 AM
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These (00-01s) have cam position sensors, right? I've heard they can cause crank no starts too. Might want to check that on your nieces' XJ.

The SKIMS issue on yours though... I have no help for you. You might have to have it re-flashed by a dealer.
Old 11-01-2020, 01:52 PM
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Originally Posted by Battle
These (00-01s) have cam position sensors, right? I've heard they can cause crank no starts too. Might want to check that on your nieces' XJ.

The SKIMS issue on yours though... I have no help for you. You might have to have it re-flashed by a dealer.

Thanks Battle,

I was trying to avoid pulling the cam sync, but I did this morning, it was toast. The gears were all worn to nothing.

Working on TDC now to replace.

Then back to the SKIM problem.....

Thanks

J
Old 11-01-2020, 01:54 PM
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When you say replaced CPS, was that camshaft or crankshaft? I had the same crank no start issue at the beginning of the year and I replaced the crankshaft position sensor and it cleared right up. I didnt replace the camshaft sensor.
Old 11-02-2020, 01:51 PM
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Call up these guys to remove SKIM from ECUs:

http://autocomputerperformance.com/
Old 11-07-2020, 10:19 PM
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Thank you Gentlemen,

Turned out the Nieces car was a cam sychro / cam position sensor.

The synchro was completely chewed up. I changed the oil and replaced the synchro and she fired right up.

Going to have to look into why this happened, my XJ has 260K on the original camsynchro...

My XJ is having the PCM sent off to have a Security Delete performed.....

Many Thanks

J
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Old 11-18-2020, 01:24 PM
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PCM successfully reset to remove the SKIM

XJ fired right up!

Thank you all for your help!
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Old 11-18-2020, 03:48 PM
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Just a point of information. The cam sensor sends data to the PCM it control fuel timing! It has no ignition function at all. The ignition timing on waste spark engines, those with the coil rail, is controlled by the PCM reading the windows in the flex plate, among other data. IIIRC, the edge of the first window opening is 4* BTDC. The window for #1 is slightly different and the PCM knows this. The cam sensor must be set to zero with a DRB scan tool for the injector pulse to be correct. It can compensate up to 7* + or - and still function.

Take a look at the drive tangs on the oil pump with a flashlight to see if one of them is broken. If it is, this allows the cam sensor drive to wobble and tear up the gears, both on the cam and the drive.
Old 11-18-2020, 04:02 PM
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Originally Posted by dave1123
Just a point of information. The cam sensor sends data to the PCM it control fuel timing! It has no ignition function at all. The ignition timing on waste spark engines, those with the coil rail, is controlled by the PCM reading the windows in the flex plate, among other data. IIIRC, the edge of the first window opening is 4* BTDC. The window for #1 is slightly different and the PCM knows this. The cam sensor must be set to zero with a DRB scan tool for the injector pulse to be correct. It can compensate up to 7* + or - and still function.

Take a look at the drive tangs on the oil pump with a flashlight to see if one of them is broken. If it is, this allows the cam sensor drive to wobble and tear up the gears, both on the cam and the drive.


Thanks Dave!

I glanced at the oil pump drive slot in order to line it up with the synchro, but I didn't really examine it. I will definitely take a look.

I am very concerned as to WHY the synchro gears were so chewed up. I am concerned for the gears on the cam. I know they are surface hardened, but I am still concerned...

Thanks Again!

J
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