Hi listers,
I just got home after a frustrating problem on my 1993 6 cyl 4.0L XJ-S.
Here in Vancouver, the sun sets about 4:30 pm. I parked the car at 8:00 am
this morning and did not run it again all day. Last night it was parked in
the underground car park at our condo. The temperature when I went out to
the car at 7:00 pm this evening was approx. -3 deg C.
The car started easily enough, but the “Check Engine” icon came on and the
car died within 10 seconds of starting. After waiting about 20 seconds, it
started again, but with a very rough idle and it would die unless I revved
the engine to the 1300-1700 rpm range. I managed to drive around the
parking lot with this coughing, spluttering rough running beast. After
about 10 minutes of this, it started to smooth out. Once the temp gauge
showed approx. 2 notches below the normal temp range (dead center in the
gauge), the car ran fine. It ran fine all the way home (16 miles), didn’t
die at the stop lights and showed no repeat of the problem.
Could this be a coolant temp or air temp sensor? Any and all help is
appreciated as this is my daily driver for about the next 2 weeks.
Regards,
Brad Miller
1993 XJ-S 4.0L 53,500 miles
1998 XJ8 10,000 miles
Posting to both the XJS list and the modern list due to the use of the 4.0L
6 cyl. engine in both cars.*****************************************
Please visit our website at:
www.camanomarine.com
Brad: What fuel fail code came from the check engine warning?
That should point you in the right direction.
Your first guess of the coolant sensor seems likely.
I’ve recently had similar rough running after having battery disconnected.
Once you get it figured out it should start and run fine in the cold weather,
I’m on my second winter here in Edmonton.
Best of luck
Richard Drozdowski
1992 XJS-4.0L (91,000 kms)Date: Tue, 21 Nov 2000 20:21:42 -0800
From: “Brad Miller” camano@direct.ca
Subject: [modern] Cold start problem
Hi listers,
I just got home after a frustrating problem on my 1993 6 cyl 4.0L XJ-S.
Here in Vancouver, the sun sets about 4:30 pm. I parked the car at 8:00 am
this morning and did not run it again all day. Last night it was parked in
the underground car park at our condo. The temperature when I went out to
the car at 7:00 pm this evening was approx. -3 deg C.
The car started easily enough, but the “Check Engine” icon came on and the
car died within 10 seconds of starting. After waiting about 20 seconds, it
started again, but with a very rough idle and it would die unless I revved
the engine to the 1300-1700 rpm range. I managed to drive around the
parking lot with this coughing, spluttering rough running beast. After
about 10 minutes of this, it started to smooth out. Once the temp gauge
showed approx. 2 notches below the normal temp range (dead center in the
gauge), the car ran fine. It ran fine all the way home (16 miles), didn’t
die at the stop lights and showed no repeat of the problem.
Could this be a coolant temp or air temp sensor? Any and all help is
appreciated as this is my daily driver for about the next 2 weeks.
Regards,
Brad Miller
1993 XJ-S 4.0L 53,500 miles
Brad,
The intake air temp sensor will not cause problems, as all
it does is retard the timing in warm conditions.
The coolant temp sensor is suspect, and the MAF sensor.
The coolant temp sensor should read a high resistance when its cold out, a
low resistance when the coolant is hot.
The range is around 6000 ohms at 32 F to 250 ohms at 192 F.
The MAF is more complex, but both are not likely to be bad, more likely the
connections are dirty.
You could also have ice in the fuel lines, injector, ect.
You also need good plugs to ignite the mixture when its cold out.
Brett
1990 XJ6
The other day I posted a problem with the cold start.
The ECU was overhauled with the following items addressed, a couple of
capacitors were replaced, the MAP sensor was recalibrated, the cold
start circuit was improved with a change to a diode (I think) and a few
cold joints were redone. Major improvement, The car was easier to start
but not great, the coolant temp sensor noted prior to this as being out
of spec. The readings at 15 deg was 2.88kOhm, the correct reading should
have been much higher. At lower temperatures the resistance vs temp
curve is very steep.
From a recent post stated “a low resistance reading results in a weak
mixture” can anyone advise or confirm this?. It would support some of
the results I have noted, but which to confirm more accurately.
Thanks folks
Kevin Whitehead
'85 xjs, (CEI) Supra 5 speed, “MY XJS”
Pioneer ODR sound system
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I have rebuilt an '86 XJS from an engine fire. Project is complete
(is it ever over with this car?) and now I have been driving a
little. I think I may have about 4 hours total on her and no
issues except:
When the car is in the garage it starts just fine when cold. AAV
is working fine. CTS must be sending the correct signal as there
is no flooding, just a clean start in about half a turn.
The other day I parked the car outside overnight while the temp
dropped to about 32F. Went to start and the response would match
that of a failed or disconnected CTS. I got the engine to rev up a
bit and it chugged along for about a minute or less and then slowly
began to clear up. A lot of raw gasoline smoke in the air, etc.
Don’t worry, no cat fires on this car.
So, this has happened about 3 or 4 times when the temp is a little
lower than it might be in the toasty garage.
I am sure the issue is associated with the CTS or the connection.
Has anyone experianced this? Is it possible that the connector
than snaps to the top of the CTS is not making good contact until
the thing warms a little or vibrates?
Mike Moyer–
M. Moyer with 1ea 82 XJ6, 86 XJS
Turner, Oregon, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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