[x300] Stalls at idle, fine at RPM. Is it crankshaft position sensor?

Occasionally (but getting more frequent), the car seems to
start fine, but as soon as I release the key, it dies UNLESS
I give it sufficient throttle to keep it about 500 or
600RPM. It happened to me again yesterday. I was able to
drive it semi-normally by keeping my foot on the throttle
and watching the tach to keep it from dropping while slowing
down or stopping/shifting. I got to my destination (2
miles), and when I got back, it started and ran fine the
rest of the evening. My wife has it today and it was fine
all morning (multiple errands) until she tried to start it
to return home. It died when she tried to start it, and
probably died 10 times between backing out, shifting,
signals, stop signs and pedestrians in cross walks. I
suspect it will be fine later in the day. There is no check
engine light on; I’m assuming there won’t be any code that
says what the problem is. It has been suggested that it
might be the crankshaft position sensor since the engine
‘‘learns’’ to cope with problems. Does that sound right (if
so I’ll bite the bullet and pay a preimum for one from the
local dealer rather than ordering it and waiting until next
week). What else could it be? Or is this it?

Thanks in advance.–
Gordon, '97 XJ6L, San Francisco Bay Area, California, USA
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

In reply to a message from slmskrs sent Thu 28 Apr 2011:

It COULD be. Or it could be any of several fueling sensors that
take care of mixture at idle, like the temperature transducers and
so on. If you had an OBD scanner, it would be good to look at the
LTFT and STFT and the ait temp sensor readings.–
Ross - 89 XJS, 98 XJR, 99 XJR, 02 XJ8
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On top of all that it could be an idle control motor. Looks like some time
with the scanner is in order. Throwing parts at it just to see if they
stick can get a bit pricey.

Cheers,
Jack - '99 XJ8L PA USA

< snip >

In reply to a message from slmskrs sent Thu 28 Apr 2011:

It COULD be. Or it could be any of several fueling sensors that
take care of mixture at idle, like the temperature transducers and
so on. If you had an OBD scanner, it would be good to look at the
LTFT and STFT and the ait temp sensor readings.–
Ross - 89 XJS, 98 XJR, 99 XJR, 02 XJ8
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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< snip >

FWIW, I’d give the throttle body a good cleaning. Can’t hurt. Might help.
Costs virtually nothing.

Cheers
Doug Dwyer
Longview Washington USA
1995 XJRFrom: “slmskrs” gordonjensen@sbcglobal.net

What else could it be? Or is this it?

In reply to a message from Doug Dwyer sent Thu 28 Apr 2011:

I Agree with both Jack and Doug,
I would clean the throttle body, do not remove the ICVS, but a
little cleaner from the body side does not hurt,

Be carefull that no fluid seeps / leaks into the position sensor !!
Hold the body upside down to make sure!!

Darrell–
The original message included these comments:

FWIW, I’d give the throttle body a good cleaning. Can’t hurt. Might help.
Costs virtually nothing.


78 XJ-S 95 X-300 http://www.jag-lovers.org/v.htm?1287957641
Delavan Wi., United States
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In reply to a message from Darrell G sent Thu 28 Apr 2011:

Could be tps, cts, ckps,egr valve
or (very unlikely) maf. On this
type of failure I would rule out
coils or iscv, although anything is
possible.

Having a clean throttle body and
checking for water on ecu
connectors should be part of
routine maintenance IMO

Regardless of wether you choose to throw parts at the car
or go thru a diagnosis process I do not use aftermarket
electronic parts. Trust me you will just add another
headache–
95 AJ16 4liter 6cylinder
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In reply to a message from Mark Janzic sent Fri 29 Apr 2011:

Last time I has the problem, I put the ODB reader on it and
didn’t get any error codes (will try again this weekend, but
the check engine light isn’t on). As for looking at the
settings / readings of the various sensors through the ODB
reader, does anyone have example numbers for the straight 6?
I can see obvious things like temp, etc., but some of them I
don’t have any idea of what ‘‘normal’’ readings should be.
I’ll do a scan and see if I can capture it and post it.
I’ll also do the cleaning (although since it is literally an
on and off problem (runs perfectly almost all the time and
generally will be fine after turning it off and leaving it
for a little while (hot or cold)). Thanks for all the
feedback; I’ve got some work to do over the weekend (no, I
don’t want to throw parts at it!!! :-)–
Gordon, '97 XJ6L, San Francisco Bay Area, California, USA
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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In reply to a message from slmskrs sent Fri 29 Apr 2011:

Check out the websites of Jim Butterworth and jagsongas
(Steve Sparrow), lots of relevant info there. OBD11 does not
implement well on the X300, a scanner is somewhat better.

http://www.watchet.dolphins.btinternet.co.uk/

Hopefully the 2nd. URL will take you to X300 Faults.–
The original message included these comments:

for a little while (hot or cold)). Thanks for all the
feedback; I’ve got some work to do over the weekend (no, I
don’t want to throw parts at it!!! :slight_smile:


Neil '97 3.2Sport http://www.jag-lovers.org/v.htm?1242166704
MALDON, United Kingdom
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In reply to a message from Neil Maldon sent Sat 30 Apr 2011:

For the 2nd URL:

Coversion Gallery
Jaguar
Our General Pages including common Faults

Then your model etc.–
The original message included these comments:

Hopefully the 2nd. URL will take you to X300 Faults.


Neil '97 3.2Sport http://www.jag-lovers.org/v.htm?1242166704
MALDON, United Kingdom
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In reply to a message from slmskrs sent Fri 29 Apr 2011:

With all the things I have thrown at my car and then
lamented it, there are four specific parts I do not regret
throwing since it seems inevitable that they will fail: #1
crank sensor #2 throttle possition sensor #3 ignition coils
4# coolant temp sensor

I just had a 2 month struggle with a problem similar to
yours and it appears that it all went back to corroded
grounds (bad ground took out alternator, alternator starts
leaking current thru ground and shorts out ecu and maf
sensor etc etc)–
The original message included these comments:

feedback; I’ve got some work to do over the weekend (no, I
don’t want to throw parts at it!!! :slight_smile:


95 AJ16 4liter 6cylinder
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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