[xj] hard start - great running question

Hello again all:

I’ve been working away on my SIII preparing for the winter replacing
fuses, bulbs and tuning up a little before it gets cold and wet…

since I replaced my oxygen sensor and cleaned out the distributor cap
I’ve had a really silky responsive car that’s a pleasure to drive
with a really smooth tick over once it’s hot.

Starting from cold is however, for the first time since I’ve had the
car, relatively difficult. I often have to crank three or four times
to get the engine to fire and then it seems to run rich for a few
minutes until I build heat in the motor.

What do I need to tweak to get back to the old smoothie I used to
enjoy when cold?

Thanks all!===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
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Here’s a couple of thoughts, off-the-cuff…

  1. Cold start injector control circuit is staying on too long and creating a
    too-rich mixture. If interested I can give details on checking this part of
    the system.
  2. The system is “double fueling”, a phenomenon which seems to occur with
    age. Your Jag may be a prime candidate for the “Capacitor Mod”. Tons of info
    on this in the archives and, I think, in the FAQ section.
  3. Coolant temp sensor is on the fritz and sending a signal to the ECU
    indicating the engine is colder than it really is. If you’re in the mood for
    guesswork, this is the place to start. Only $20 or so for a sensor and 5
    minutes to install.

Oddly, though, extended cranking on a cold start…as you’ve indicated…
would normally indicate a lean mixture which still could be attributable to
a faulty cold-start circuit or bum coolant sensor. Are you getting black
smoke from the exhaust ?

Doug Dwyer
Longview, Washington USA----- Original Message -----
From: “Oliver Marks” omarks@rpminteractive.com

Starting from cold is however, for the first time since I’ve had the
car, relatively difficult. I often have to crank three or four times
to get the engine to fire and then it seems to run rich for a few
minutes until I build heat in the motor.

What do I need to tweak to get back to the old smoothie I used to
enjoy when cold?

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

Doug,
I read your reply to Oliver. I suspect my cold start injector circuit is
staying on too long at times. There are mornings when the idle is extremely
rough at start, the exhaust is very rich smelling, and the exhaust is black.
It doesn’t matter how long I run the engine, the rough idle will never go
away and the engine will in fact die unless I keep the accelerator applied.
If I cut the engine and let it sit for 10 minutes or so, I can restart it
and the idle will be fine. On that second start, though, it takes some
cranking, like it’s flooded. There are times, however, that it starts fine
the first time and the idle is just as it should be. You mentioned being
able to check the injector control circuit. Can you pass along the details?
Thanks.

Eric
'87 XJ6 US

Date: Sun, 24 Sep 2000 23:08:31 -0700
From: “Doug Dwyer” DWYERD@email.msn.com
Subject: Re: [xj] hard start - great running question

Here’s a couple of thoughts, off-the-cuff…

  1. Cold start injector control circuit is staying on too long and creating
    a
    too-rich mixture. If interested I can give details on checking this part of
    the system.
  2. The system is “double fueling”, a phenomenon which seems to occur with
    age. Your Jag may be a prime candidate for the “Capacitor Mod”. Tons of
    info
    on this in the archives and, I think, in the FAQ section.
  3. Coolant temp sensor is on the fritz and sending a signal to the ECU
    indicating the engine is colder than it really is. If you’re in the mood
    for>guesswork, this is the place to start. Only $20 or so for a sensor and 5
    minutes to install.

Oddly, though, extended cranking on a cold start…as you’ve indicated…
would normally indicate a lean mixture which still could be attributable to
a faulty cold-start circuit or bum coolant sensor. Are you getting black
smoke from the exhaust ?

Doug Dwyer
Longview, Washington USA

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/xjfaq.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.