On Sep 5, 8:24 pm, Lon <lon.stow...@comcast.net> wrote:
> nrs proclaimed:
>
>
>
> > On Sep 3, 3:58 pm, Lon <lon.stow...@comcast.net> wrote:
>
> >>nrs proclaimed:
>
> >>>On Sep 3, 2:10 pm, Lon <lon.stow...@comcast.net> wrote:
>
> >>>>ufatbastehd proclaimed:
>
> >>>>>On Sep 3, 12:58 pm, nrs <neale...@yahoo.com> wrote:
>
> >>>>>>On Sep 3, 11:38 am, ufatbastehd <ufatbas...@gmail.com> wrote:
>
> >>>>>>>On Sep 3, 12:31 pm, nrs <neale...@yahoo.com> wrote:
>
> >>>>>>>>Went on a wheeling trip this weekend and had some problems with the
> >>>>>>>>'95 YJ, 2.5L, AX5. The check engine light would not turn on and the
> >>>>>>>>fuel pump was not activating. Engine would turn over fine but would
> >>>>>>>>not start. Also dash would illuminate, fuel gauge activated, etc. It
> >>>>>>>>did start after trying many more times and once started would run
> >>>>>>>>perfectly, no misses, no stalling, no hesitation. Any ideas? Thanks,
> >>>>>>>>Neale
>
> >>>>>>>CPS?
>
> >>>>>>Might be but I think the check engine light and fuel pump should still
> >>>>>>run for a short while with the key on RUN even if the CPS is bad. I
> >>>>>>don't know, maybe a bad ground or bad computer?
>
> >>>>>I've had a ground problem with my fuel pump but it did affect the gas
> >>>>>gauge, the gas gauge pegs to full when the fuel pump cuts out. I think
> >>>>>the check engine light acted as usual. You stated your gas gauge
> >>>>>activated so it could be another issue/ground
> >>>>>There is a fuel pump ground that's by the e-brake mounting brackets
> >>>>>on most YJs.
>
> >>>>>I havn't found the bad ground yet as my YJ has no grounds on the e
> >>>>>brake mounting cable.
>
> >>>>Does sound like a bad ground, or possibly just bad battery connect. IF
> >>>>it truly runs after starting, the alternator would appear to be able to
> >>>>pump enough juice to keep voltage up even with a bad ground or cabling- Hide quoted text -
>
> >>>>- Show quoted text -
>
> >>>Thanks for that idea, I hadn't thought about that possibility. I'm
> >>>still thinking bad ground because the starter works well so maybe it
> >>>is just the ground to the computer that is bad. I'll try cleaning all
> >>>ground straps and connections and get a new battery since it may be
> >>>getting old (was in jeep when I bought it about 1.5 years ago).
>
> >>If you don't know the history of that battery, it never hurts, some of
> >>the cheapest cab fare and tow truck charge prevention available.
>
> >>If you don't already have one, pick up an inexpensive digital
> >>volt-ohmmeter. You want a digital, as checking grounds and power
> >>cables requires better than 1 tenth volt accuracy. More accurate than
> >>using an ohmmeter.
>
> >>First run your engine so the battery is presumably charged and at
> >>operating temperature.
>
> >>Then turn your engine off.
>
> >>Turn your headlights on bright for at least 30 seconds, then turn them
> >>off.
>
> >>Wait 5 to 10 minutes.
>
> >>Pull the negative lead at the battery.
>
> >>Measure across the battery. Absolute minimum 12.4 volts [this is the
> >>open circuit test] Then hook up the negative lead again.
>
> >>True load test is expensive equipment, but mostly free at any place that
> >>sells batteries.
>
> >>To test current drain with the key off. Pull the key, pull the
> >>negative lead. Hook an ammeter set at the very highest scale between
> >>the battery post and the negative lead. Reasonable typical drain is 20
> >>milliamps. Turn your meter down slowly to lower scales to check.
> >>[Starting at the highest scale helps keep the magic smoke inside the
> >>meter where it belongs]
>
> >>Easiest way to check cables is to measure the voltage across them.
> >>Again, start on at least a 12 volt scale at each reading, then turn the
> >>scale down so you can easily see a voltage of 1 to 2 tenths of a volt.
>
> >>Measure from each battery post to the connector at that post. With the
> >>engine cranking, you should never see as much as 2 tenths of a volt from
> >>each post to its connector.
>
> >>Measure from the negative post [not the connector] to body ground and
> >>then again to engine ground. With the engine cranking, absolute highest
> >> reading should be 2 tenths of a volt. Anything higher, you got a bad
> >>connect or cable.
>
> >>Check from positive post [not the connector] down to the starter
> >>solenoid. With engine cranking, again, no more than 2 tenths of a volt.
> >>If you can reach across the solenoid, measure straight from the battery
> >>positive post to the input to the starter while cranking. Again, no
> >>more than 2 tenths of a volt.
>
> >>If you find a higher reading, just move the meter leads until you find
> >>the connection with the highest reading, take it apart and clean the
> >>snot out of it, put back together and retry.
>
> >>Lather, rinse, repeat.- Hide quoted text -
>
> >>- Show quoted text -
>
> > Here is an update, positive but not very satisfying. Yesterday I made
> > sure all the fuses were OK and pushed them in firmly. Tried to start
> > and no go. Then I checked the voltages at the relay cavities to see if
> > the battery voltage was present whith the ignition on RUN (and not
> > present with ignition off). It was fine so it looks like the ignition
> > switch is not the problem. I then checked at the computer data link
> > and it had a ground and power from the ignition. I then turned off
> > the ignition and turned it back to RUN and the check engine light came
> > on! I was pretty surprised. I then put the relays back in and it
> > started right up. Since then I have started it about 3 times with no
> > problems and have verified about 20-30 times that the fuel pump runs
> > each time the ignition switch goes to RUN. Also, no relevant codes
> > come up with the on-off-on-off-on method. It seems to be working fine
> > now. What bothers me is that I didn't do anything to fix it and this
> > type of fix tends to unfix later. Could the computer have been reset
> > in some way when checking at the data link?
>
> Doncha hate that when that happens.
>
> By any chance, was your local weather rather cool and humid when it
> wouldnt work? I've seen that, in combination with corrosion on
> contacts, be just the last straw in turning a working contact into a not
> so working contact. You pound on stuff, you pull wires and put them
> back... and the problem goes away until the next cool wet spell. In my
> case it was corrosion inside the ignition switch--which the local
> service manager claimed "those never fail like that".- Hide quoted text -
>
> - Show quoted text -

Yes, that was exactly the kind of weather in the area. I live at 1500
feet but when it first failed we were up near 10,500 feet, cold and
rainy. When I checked the computer ground at the data link it had a
small voltage drop across the connector and the engine block. I'll
take that as a sign the ground is a bit bad so I'll be cleaning it
this weekend along with all the relay connections. Thanks for your
help with this.

 

On Sep 3, 11:31 am, nrs <neale...@yahoo.com> wrote:
> Went on a wheeling trip this weekend and had some problems with the
> '95 YJ, 2.5L, AX5. The check engine light would not turn on and the
> fuel pump was not activating. Engine would turn over fine but would
> not start. Also dash would illuminate, fuel gauge activated, etc. It
> did start after trying many more times and once started would run
> perfectly, no misses, no stalling, no hesitation. Any ideas? Thanks,
> Neale

The problem came back and I finally took it to the dealership where
they confirmed that the problem is the PCM. I'll be looking for a
used PCM now. Thanks for all the help.

 

On Sep 3, 11:31 am, nrs <neale...@yahoo.com> wrote:
> Went on a wheeling trip this weekend and had some problems with the
> '95 YJ, 2.5L, AX5. The check engine light would not turn on and the
> fuel pump was not activating. Engine would turn over fine but would
> not start. Also dash would illuminate, fuel gauge activated, etc. It
> did start after trying many more times and once started would run
> perfectly, no misses, no stalling, no hesitation. Any ideas? Thanks,
> Neale

The problem came back and I finally took it to the dealership where
they confirmed that the problem is the PCM. I'll be looking for a
used PCM now. Thanks for all the help.

 

On Sep 3, 11:31 am, nrs <neale...@yahoo.com> wrote:
> Went on a wheeling trip this weekend and had some problems with the
> '95 YJ, 2.5L, AX5. The check engine light would not turn on and the
> fuel pump was not activating. Engine would turn over fine but would
> not start. Also dash would illuminate, fuel gauge activated, etc. It
> did start after trying many more times and once started would run
> perfectly, no misses, no stalling, no hesitation. Any ideas? Thanks,
> Neale

The problem came back and I finally took it to the dealership where
they confirmed that the problem is the PCM. I'll be looking for a
used PCM now. Thanks for all the help.

 

On Sep 3, 11:31 am, nrs <neale...@yahoo.com> wrote:
> Went on a wheeling trip this weekend and had some problems with the
> '95 YJ, 2.5L, AX5. The check engine light would not turn on and the
> fuel pump was not activating. Engine would turn over fine but would
> not start. Also dash would illuminate, fuel gauge activated, etc. It
> did start after trying many more times and once started would run
> perfectly, no misses, no stalling, no hesitation. Any ideas? Thanks,
> Neale

The problem came back and I finally took it to the dealership where
they confirmed that the problem is the PCM. I'll be looking for a
used PCM now. Thanks for all the help.

 

Thanks for telling us it was the Powertrain Control Module, I believe
there has been only one other incidence of it's replacement here.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

"nrs" <neale_rs@yahoo.com> wrote in message
news:1192055011.885219.105940@k79g2000hse.googlegr oups.com...
>
> The problem came back and I finally took it to the dealership where
> they confirmed that the problem is the PCM. I'll be looking for a
> used PCM now. Thanks for all the help.
>

 

Thanks for telling us it was the Powertrain Control Module, I believe
there has been only one other incidence of it's replacement here.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

"nrs" <neale_rs@yahoo.com> wrote in message
news:1192055011.885219.105940@k79g2000hse.googlegr oups.com...
>
> The problem came back and I finally took it to the dealership where
> they confirmed that the problem is the PCM. I'll be looking for a
> used PCM now. Thanks for all the help.
>

 

Thanks for telling us it was the Powertrain Control Module, I believe
there has been only one other incidence of it's replacement here.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

"nrs" <neale_rs@yahoo.com> wrote in message
news:1192055011.885219.105940@k79g2000hse.googlegr oups.com...
>
> The problem came back and I finally took it to the dealership where
> they confirmed that the problem is the PCM. I'll be looking for a
> used PCM now. Thanks for all the help.
>

 

Thanks for telling us it was the Powertrain Control Module, I believe
there has been only one other incidence of it's replacement here.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

"nrs" <neale_rs@yahoo.com> wrote in message
news:1192055011.885219.105940@k79g2000hse.googlegr oups.com...
>
> The problem came back and I finally took it to the dealership where
> they confirmed that the problem is the PCM. I'll be looking for a
> used PCM now. Thanks for all the help.
>