argh, 90 xj starting revisited (cps?)

Damn, just when I fix one thing its another...

The other day in traffic it died at a particularly busy intersection here in
town, but after the hood up and me plugging and unplugging the cps sensor a
few times it starts up and I drive to where I was going. An hour after
there I go to leave and it wont start. I try my tricks again for about
15-20 minutes... no go. So we push the thing over to the side to park it
and so I can get a ride, and just for fun I tried it again and now it will
start.

Got it home that night and now it won't crank again. Just sitting there
cold this time. I replaced the cps sensor a few months ago, and cleaned all
my connectors. Seems like its heat related most of the time, as if by me
lifting the hood so air can cool it a bit seems to work a little. The temp
needle doesnt' show it getting hot though. My idle is low I know and only
when its in gear... maybe I need to change the auto tranny fluid?

I'm about this close | | to selling it only because with this new job I need
very reliable transportation. Any more ideas?

Troy

When my 88 did that it had a rotted mesh ground strap from the rear of
the engine head to the firewall.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Troy wrote:
>
> Damn, just when I fix one thing its another...
>
> The other day in traffic it died at a particularly busy intersection here in
> town, but after the hood up and me plugging and unplugging the cps sensor a
> few times it starts up and I drive to where I was going. An hour after
> there I go to leave and it wont start. I try my tricks again for about
> 15-20 minutes... no go. So we push the thing over to the side to park it
> and so I can get a ride, and just for fun I tried it again and now it will
> start.
>
> Got it home that night and now it won't crank again. Just sitting there
> cold this time. I replaced the cps sensor a few months ago, and cleaned all
> my connectors. Seems like its heat related most of the time, as if by me
> lifting the hood so air can cool it a bit seems to work a little. The temp
> needle doesnt' show it getting hot though. My idle is low I know and only
> when its in gear... maybe I need to change the auto tranny fluid?
>
> I'm about this close | | to selling it only because with this new job I need
> very reliable transportation. Any more ideas?
>
> Troy

Heh yeah checked that. Seems good, I tugged on it a few times and it holds
well. I was just outside trying to mess with it and remembered another guy
I talked to who had the same problem and he replaced his ignition control
module... Said it was a royal PITA but it hasn't given him problems since.
I'm wondering if I'm going to have to do the same. Is there a way I can
tell if its bad?

Troy


"Mike Romain" > wrote in message
...
> When my 88 did that it had a rotted mesh ground strap from the rear of
> the engine head to the firewall.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
> Troy wrote:
>>
>> Damn, just when I fix one thing its another...
>>
>> The other day in traffic it died at a particularly busy intersection here
>> in
>> town, but after the hood up and me plugging and unplugging the cps sensor
>> a
>> few times it starts up and I drive to where I was going. An hour after
>> there I go to leave and it wont start. I try my tricks again for about
>> 15-20 minutes... no go. So we push the thing over to the side to park it
>> and so I can get a ride, and just for fun I tried it again and now it
>> will
>> start.
>>
>> Got it home that night and now it won't crank again. Just sitting there
>> cold this time. I replaced the cps sensor a few months ago, and cleaned
>> all
>> my connectors. Seems like its heat related most of the time, as if by me
>> lifting the hood so air can cool it a bit seems to work a little. The
>> temp
>> needle doesnt' show it getting hot though. My idle is low I know and
>> only
>> when its in gear... maybe I need to change the auto tranny fluid?
>>
>> I'm about this close | | to selling it only because with this new job I
>> need
>> very reliable transportation. Any more ideas?
>>
>> Troy

Remove the ground strap, clean it, clean the connections on both ends and
see if that helps. Check every wire and every ground before you go
shotgunning new parts at it.

Carl


"Troy" <@ .> wrote in message
. ..
> Heh yeah checked that. Seems good, I tugged on it a few times and it
> holds well. I was just outside trying to mess with it and remembered
> another guy I talked to who had the same problem and he replaced his
> ignition control module... Said it was a royal PITA but it hasn't given
> him problems since. I'm wondering if I'm going to have to do the same.
> Is there a way I can tell if its bad?
>
> Troy
>
>
> "Mike Romain" > wrote in message
> ...
>> When my 88 did that it had a rotted mesh ground strap from the rear of
>> the engine head to the firewall.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Troy wrote:
>>>
>>> Damn, just when I fix one thing its another...
>>>
>>> The other day in traffic it died at a particularly busy intersection
>>> here in
>>> town, but after the hood up and me plugging and unplugging the cps
>>> sensor a
>>> few times it starts up and I drive to where I was going. An hour after
>>> there I go to leave and it wont start. I try my tricks again for about
>>> 15-20 minutes... no go. So we push the thing over to the side to park
>>> it
>>> and so I can get a ride, and just for fun I tried it again and now it
>>> will
>>> start.
>>>
>>> Got it home that night and now it won't crank again. Just sitting there
>>> cold this time. I replaced the cps sensor a few months ago, and cleaned
>>> all
>>> my connectors. Seems like its heat related most of the time, as if by
>>> me
>>> lifting the hood so air can cool it a bit seems to work a little. The
>>> temp
>>> needle doesnt' show it getting hot though. My idle is low I know and
>>> only
>>> when its in gear... maybe I need to change the auto tranny fluid?
>>>
>>> I'm about this close | | to selling it only because with this new job I
>>> need
>>> very reliable transportation. Any more ideas?
>>>
>>> Troy
>
>

AutoZone can check some Ignition Modules, give them a call

"Troy" <@ .> wrote in message
. ..
> Heh yeah checked that. Seems good, I tugged on it a few times and it
> holds well. I was just outside trying to mess with it and remembered
> another guy I talked to who had the same problem and he replaced his
> ignition control module... Said it was a royal PITA but it hasn't given
> him problems since. I'm wondering if I'm going to have to do the same.
> Is there a way I can tell if its bad?
>
> Troy
>
>
> "Mike Romain" > wrote in message
> ...
>> When my 88 did that it had a rotted mesh ground strap from the rear of
>> the engine head to the firewall.
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 88 Cherokee 235 BFG AT's
>> Canadian Off Road Trips Photos: Non members can still view!
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
>>
>> Troy wrote:
>>>
>>> Damn, just when I fix one thing its another...
>>>
>>> The other day in traffic it died at a particularly busy intersection
>>> here in
>>> town, but after the hood up and me plugging and unplugging the cps
>>> sensor a
>>> few times it starts up and I drive to where I was going. An hour after
>>> there I go to leave and it wont start. I try my tricks again for about
>>> 15-20 minutes... no go. So we push the thing over to the side to park
>>> it
>>> and so I can get a ride, and just for fun I tried it again and now it
>>> will
>>> start.
>>>
>>> Got it home that night and now it won't crank again. Just sitting there
>>> cold this time. I replaced the cps sensor a few months ago, and cleaned
>>> all
>>> my connectors. Seems like its heat related most of the time, as if by
>>> me
>>> lifting the hood so air can cool it a bit seems to work a little. The
>>> temp
>>> needle doesnt' show it getting hot though. My idle is low I know and
>>> only
>>> when its in gear... maybe I need to change the auto tranny fluid?
>>>
>>> I'm about this close | | to selling it only because with this new job I
>>> need
>>> very reliable transportation. Any more ideas?
>>>
>>> Troy
>
>

I had similar symptoms with my '89 YJ.
Pep-boys checked my ignition module, told
me it was bad, sold me new one, no problem since.
Joe C

"billy ray" > wrote in message
...
> AutoZone can check some Ignition Modules, give them a call
>
> "Troy" <@ .> wrote in message
> . ..
> > Heh yeah checked that. Seems good, I tugged on it a few times and it
> > holds well. I was just outside trying to mess with it and remembered
> > another guy I talked to who had the same problem and he replaced his
> > ignition control module... Said it was a royal PITA but it hasn't given
> > him problems since. I'm wondering if I'm going to have to do the same.
> > Is there a way I can tell if its bad?
> >
> > Troy
> >
> >
> > "Mike Romain" > wrote in message
> > ...
> >> When my 88 did that it had a rotted mesh ground strap from the rear of
> >> the engine head to the firewall.
> >>
> >> Mike
> >> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >> 88 Cherokee 235 BFG AT's
> >> Canadian Off Road Trips Photos: Non members can still view!
> >> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >> (More Off Road album links at bottom of the view page)
> >>
> >> Troy wrote:
> >>>
> >>> Damn, just when I fix one thing its another...
> >>>
> >>> The other day in traffic it died at a particularly busy intersection
> >>> here in
> >>> town, but after the hood up and me plugging and unplugging the cps
> >>> sensor a
> >>> few times it starts up and I drive to where I was going. An hour
after
> >>> there I go to leave and it wont start. I try my tricks again for
about
> >>> 15-20 minutes... no go. So we push the thing over to the side to park
> >>> it
> >>> and so I can get a ride, and just for fun I tried it again and now it
> >>> will
> >>> start.
> >>>
> >>> Got it home that night and now it won't crank again. Just sitting
there
> >>> cold this time. I replaced the cps sensor a few months ago, and
cleaned
> >>> all
> >>> my connectors. Seems like its heat related most of the time, as if by
> >>> me
> >>> lifting the hood so air can cool it a bit seems to work a little. The
> >>> temp
> >>> needle doesnt' show it getting hot though. My idle is low I know and
> >>> only
> >>> when its in gear... maybe I need to change the auto tranny fluid?
> >>>
> >>> I'm about this close | | to selling it only because with this new job
I
> >>> need
> >>> very reliable transportation. Any more ideas?
> >>>
> >>> Troy
> >
> >
>
>

I've had a couple of ECU problems that sound similar - runs fine until
it gets hot then rolls over and dies until it cools down. The
difference is that this one seems to be bad cold as well - which
sounds more like a contact problem (maybe inside the module). Being a
long-time electronics victim, every one I had would come alive if I
cooled them then die again as they heated up. Any way you can cool
them seems to work - pour some water on them, wet rags, CO2 blast or
- as a last resort - **** on it. It is a little inconvenient to
reach, tho.

Most parts stores have tester that can verify the problem before you
spend any money on it once you have it out.

On Fri, 18 Aug 2006 18:45:24 UTC "Troy" <@á.> wrote:

> Heh yeah checked that. Seems good, I tugged on it a few times and it holds
> well. I was just outside trying to mess with it and remembered another guy
> I talked to who had the same problem and he replaced his ignition control
> module... Said it was a royal PITA but it hasn't given him problems since.
> I'm wondering if I'm going to have to do the same. Is there a way I can
> tell if its bad?
>
> Troy
>
>
> "Mike Romain" > wrote in message
> ...
> > When my 88 did that it had a rotted mesh ground strap from the rear of
> > the engine head to the firewall.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> > Canadian Off Road Trips Photos: Non members can still view!
> > Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> > (More Off Road album links at bottom of the view page)
> >
> > Troy wrote:
> >>
> >> Damn, just when I fix one thing its another...
> >>
> >> The other day in traffic it died at a particularly busy intersection here
> >> in
> >> town, but after the hood up and me plugging and unplugging the cps sensor
> >> a
> >> few times it starts up and I drive to where I was going. An hour after
> >> there I go to leave and it wont start. I try my tricks again for about
> >> 15-20 minutes... no go. So we push the thing over to the side to park it
> >> and so I can get a ride, and just for fun I tried it again and now it
> >> will
> >> start.
> >>
> >> Got it home that night and now it won't crank again. Just sitting there
> >> cold this time. I replaced the cps sensor a few months ago, and cleaned
> >> all
> >> my connectors. Seems like its heat related most of the time, as if by me
> >> lifting the hood so air can cool it a bit seems to work a little. The
> >> temp
> >> needle doesnt' show it getting hot though. My idle is low I know and
> >> only
> >> when its in gear... maybe I need to change the auto tranny fluid?
> >>
> >> I'm about this close | | to selling it only because with this new job I
> >> need
> >> very reliable transportation. Any more ideas?
> >>
> >> Troy
>
>


--
Will Honea

Another alternative to cool it is to get a can of compressed air used for
dusting off computer parts. Hold it upside down and it emits a freezing
stream that cools and evaporates on contact.

Carl


"Will Honea" > wrote in message
...
> I've had a couple of ECU problems that sound similar - runs fine until
> it gets hot then rolls over and dies until it cools down. The
> difference is that this one seems to be bad cold as well - which
> sounds more like a contact problem (maybe inside the module). Being a
> long-time electronics victim, every one I had would come alive if I
> cooled them then die again as they heated up. Any way you can cool
> them seems to work - pour some water on them, wet rags, CO2 blast or
> - as a last resort - **** on it. It is a little inconvenient to
> reach, tho.
>
> Most parts stores have tester that can verify the problem before you
> spend any money on it once you have it out.
>
> On Fri, 18 Aug 2006 18:45:24 UTC "Troy" <@á.> wrote:
>
>> Heh yeah checked that. Seems good, I tugged on it a few times and it
>> holds
>> well. I was just outside trying to mess with it and remembered another
>> guy
>> I talked to who had the same problem and he replaced his ignition control
>> module... Said it was a royal PITA but it hasn't given him problems
>> since.
>> I'm wondering if I'm going to have to do the same. Is there a way I can
>> tell if its bad?
>>
>> Troy
>>
>>
>> "Mike Romain" > wrote in message
>> ...
>> > When my 88 did that it had a rotted mesh ground strap from the rear of
>> > the engine head to the firewall.
>> >
>> > Mike
>> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> > 88 Cherokee 235 BFG AT's
>> > Canadian Off Road Trips Photos: Non members can still view!
>> > Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> > (More Off Road album links at bottom of the view page)
>> >
>> > Troy wrote:
>> >>
>> >> Damn, just when I fix one thing its another...
>> >>
>> >> The other day in traffic it died at a particularly busy intersection
>> >> here
>> >> in
>> >> town, but after the hood up and me plugging and unplugging the cps
>> >> sensor
>> >> a
>> >> few times it starts up and I drive to where I was going. An hour
>> >> after
>> >> there I go to leave and it wont start. I try my tricks again for
>> >> about
>> >> 15-20 minutes... no go. So we push the thing over to the side to park
>> >> it
>> >> and so I can get a ride, and just for fun I tried it again and now it
>> >> will
>> >> start.
>> >>
>> >> Got it home that night and now it won't crank again. Just sitting
>> >> there
>> >> cold this time. I replaced the cps sensor a few months ago, and
>> >> cleaned
>> >> all
>> >> my connectors. Seems like its heat related most of the time, as if by
>> >> me
>> >> lifting the hood so air can cool it a bit seems to work a little. The
>> >> temp
>> >> needle doesnt' show it getting hot though. My idle is low I know and
>> >> only
>> >> when its in gear... maybe I need to change the auto tranny fluid?
>> >>
>> >> I'm about this close | | to selling it only because with this new job
>> >> I
>> >> need
>> >> very reliable transportation. Any more ideas?
>> >>
>> >> Troy
>>
>>
>
>
> --
> Will Honea

Troy wrote:

> Damn, just when I fix one thing its another...
>
> The other day in traffic it died at a particularly busy intersection here in
> town, but after the hood up and me plugging and unplugging the cps sensor a
> few times it starts up and I drive to where I was going. An hour after
> there I go to leave and it wont start. I try my tricks again for about
> 15-20 minutes... no go. So we push the thing over to the side to park it
> and so I can get a ride, and just for fun I tried it again and now it will
> start.
>
> Got it home that night and now it won't crank again. Just sitting there

Just to be clear on the symptoms: Won't crank or won't start?

"Cranking": Electric motor spins the moving parts of the gasoline motor.

"Won't start": No spark at the plugs/insufficient spark at the plugs for
ignition/spark and fuel not meeting at right time, right place.

There's a world of difference right there.


> cold this time. I replaced the cps sensor a few months ago, and cleaned all
> my connectors. Seems like its heat related most of the time, as if by me
> lifting the hood so air can cool it a bit seems to work a little. The temp
> needle doesnt' show it getting hot though.

Your factory dash gauges are vague indicators only, not precision
instruments. They are there only to show you if something is seriously
out of range. Needle someplace in the middle: Normal. Needle pegged:
Something not normal.


> My idle is low I know and only
> when its in gear... maybe I need to change the auto tranny fluid?

I don't see that helping much.


> I'm about this close | | to selling it only because with this new job I need
> very reliable transportation. Any more ideas?

At 17 years old I'd guess that most of the trouble-free and reliable
life has been sucked out of pretty much any passenger vehicle.