Why is it hard to Start when Cold

[LuluBelle]

Just to confuse the issue more I went and checked the 99 sport pcm numbers ....... 494AE
So Errrr Um I don't think I would be able to use your pcm rainman Bummer!
the only ones I can see on ebay are in the USA and with the exchange rate at the moment ......forget it I will check the wreckers and gumtree start my search I suppose might as well give a new pcm a go
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_) EDIT.. Maybe the big Number is like a batch Number?

[awg]

Originally Posted by LuluBelle

Just to confuse the issue more I went and checked the 99 sport pcm numbers ....... 494AE
So Errrr Um I don't think I would be able to use your pcm rainman Bummer!
the only ones I can see on ebay are in the USA and with the exchange rate at the moment ......forget it I will check the wreckers and gumtree start my search I suppose might as well give a new pcm a go
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_) EDIT.. Maybe the big Number is like a batch Number?

I suspect a later PCM would have some issues with an earlier vehicle, as the way it interacted with the TCM changed, so quite likely a check light at best, probably would not change gears properly, may not even start

One thing I forgot to mention, maybe you have already done, disconnect battery and discharge PCM by shorting battery terminals for a while

I see this procedure has caused some odd computer problems to disappear on this era Jeep, (and stacks of other equipment)

[LuluBelle]

Thanks for reminding me awg I remember reading about the discharge thing I will do it tomorrow as I am putting humpty Dumpty back together tomorrow
try for a start wriggle some wires ... Got to look at every angle
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[heatlocke]

Hello LuLuBelle and all here. I just joined from another site. Special thanks to JonnyJeep for linking my post. This thread is a wealth of info ! Man! 13 pages. At first I wasn`t sure our problems were related but post #43 convinced me it may well be. You have done much more testing on sensors than me and I intend to go thru this thread page by page and try some of this on mine. I got my work cut out for me. Hope to post something helpful back here soon. Thanks to everyone here ! Heatlocke

[LuluBelle]

Hi heatlocke together we will get them going again I posed the question about what the big number means on the Cherokee forum and jeepforum one guy said that the big numbers were emission control revised batch numbers another guy says "If you need a replacement PCM for a 1996 XJ, the part number must match exactly, number for number. 1996 was a transition year from OBD-I to OBD-II and there are no other model year PCM that are known to interchange."......and I am having no luck calling wreckers so far
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[LuluBelle]

WHOoooooHOOooooo! I Got a 252!........ I was looking and ringing everywhere if this didn't work I was going to get a Plug n Play from the USA the way the exchange rate is it would be around $500 posted here
BUT!.... I came across Jeep Spares in Perth.....
$195 + $15 Postage so at that price I will give a new PCM a Go
Fingers Crossed .. Time For a BEER
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

[awg]

Originally Posted by LuluBelle

$195 + $15 Postage so at that price I will give a new PCM a Go
Fingers Crossed .. Time For a BEER
_____ooooo
/__l_l_,\____\,___
l_---l_l__l---[ ]llllll[ ]
_.(o)_)__(o)_)--o-)_)

hopefully that will resolve your problem.

Presumably you mean a "new-to-you" ie used item, as far as I can tell, there is no such thing as a "NEW" '96 PCM, (unless it was a NOS item ex-Dealer stock) ?

All the others appear to be "re-manafactured" ??
(and dont have a very good reputation)

I could be wrong about there being no new ones

those videos indicate repair may be possible in many cases.
The coil would pull a lot of current...3-4 Amp in older cars

from your description of the problem gradually getting worse, there is probably a bad solder joint in the high current section of the Coil Earth Circuit in the PCM