ahhh crap.
#1
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ahhh crap.
well. since few days ago, my 98 xj8 has trouble keeping idle. when cold it starts right up but dies and after coming to operating temperature it has hard time staying on. there's no power loss nor miss when i drive the car or rev it from park. it just cannot smooth idle and wants to die! the dtc spit out p1396, which after research jaguar specific dtc says variable timing malfunction circut b. what the hell is that?????? is that the dreaded timing chain tensioner defect? the car seems to run fine without loss of power and it's smooth, yet can't retain smooth idle if it's life depended on it! i'm inches away from driving this car through the dealer front door! help!
#2
RE: ahhh crap.
Here is what the JTIS lists as posssible problems for the P1396. Has nothing to do with tensioners.
ECM to VVT solenoid valve circuit fault
(refer to P1392, P1393) - see below -
VVT solenoid valve actuator sticking
Oil supply fault
VVT unit fault
Camshaft drive fault
CKPS / CMPS circuits fault(s)
(refer to P0335, P0340) - see below -
P1392
Fault - ECM to VVT solenoid valve circuit open circuit, A bank
Possible causes - ECM to VVT solenoid valve circuit open circuit,
high resistance, short circuit to high voltage
VVT solenoid valve failure
P1393
Fault - VVT solenoid circuit short circuit A bank
Possible causes - ECM to VVT solenoid valve short circuit to ground
VVT solenoid valve failure
P0335
Fault - CKPS circuit malfunction
Possible causes - CKPS disconnected
CKPS gap incorrect / foreign matter on sensor face
CKPS sensing circuit open circuit, short circuit to ground, short circuit to high voltage CKPS failure
P0340
Fault - CMPS circuit malfunction
Possible causes - CMPS disconnected
CMPS gap incorrect / foreign matter on sensor face
CMPS sensing circuit open circuit, short circuit to ground, short circuit to high voltage
CMPS failure
ECM to VVT solenoid valve circuit fault
(refer to P1392, P1393) - see below -
VVT solenoid valve actuator sticking
Oil supply fault
VVT unit fault
Camshaft drive fault
CKPS / CMPS circuits fault(s)
(refer to P0335, P0340) - see below -
P1392
Fault - ECM to VVT solenoid valve circuit open circuit, A bank
Possible causes - ECM to VVT solenoid valve circuit open circuit,
high resistance, short circuit to high voltage
VVT solenoid valve failure
P1393
Fault - VVT solenoid circuit short circuit A bank
Possible causes - ECM to VVT solenoid valve short circuit to ground
VVT solenoid valve failure
P0335
Fault - CKPS circuit malfunction
Possible causes - CKPS disconnected
CKPS gap incorrect / foreign matter on sensor face
CKPS sensing circuit open circuit, short circuit to ground, short circuit to high voltage CKPS failure
P0340
Fault - CMPS circuit malfunction
Possible causes - CMPS disconnected
CMPS gap incorrect / foreign matter on sensor face
CMPS sensing circuit open circuit, short circuit to ground, short circuit to high voltage
CMPS failure
#3
RE: ahhh crap.
This is not timing chain tensioners. This indicates the VVT unit is bad. Either blocked or bad solenoid. A bank is passenger side (U.S.A). The VVT unit is in front of engine at top. I think you said 98 car. I think they changed half way thru model year to on top of cam covers at front of engine. If you have to replace them, do the tensioners at this time. Will save you thousands in the future.
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Highhorse (10-11-2020)
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Review this old (but still applicable) detailed thread by blackonyx on doing the chains and locking the cams, its pretty cut and dry.
Tmingi chain and tensioner replacement
Found in the "How To" section at the top of this forum... https://www.jaguarforums.com/forum/x...k-links-20090/
Tmingi chain and tensioner replacement
Found in the "How To" section at the top of this forum... https://www.jaguarforums.com/forum/x...k-links-20090/
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westbay
XJ XJ8 / XJR ( X308 )
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01-17-2009 09:05 AM
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