On Mon, 06 Sep 2004 23:42:31 GMT, "Joseph P" <jpribe@nc.rr.com> wrote:

>M. E. Bye wrote:
>| On Sat, 04 Sep 2004 07:20:47 -0500, M. E. Bye <fxdyna@hotmail.com>
>| wrote:
>|
>|| On Wed, 01 Sep 2004 17:39:45 -0500, M. E. Bye
>|| <fxdyna@hotmail.com> wrote:
>||
>||| About a week ago, my '98 TJ (2.5L, 5-speed, 71K miles) began
>||| missing at highway speed, bucking like a bronco. I chalked it
>||| up to a bad tank of gas, so I dumped in a bottle of HEET and a
>||| bottle of fuel injector cleaner. The problem continued, so I
>||| did the same thing with my next fill-up at a different station.
>||| No improvement. Since then, I've changed the plugs, installed
>||| new wires, distributor cap and rotor, have cleaned the throttle
>||| body, and have disconnected all electrical connections to the
>||| throttle body and fuel injectors and have sprayed electrical
>||| contact cleaner on them. I still have an intermittent miss at
>||| speed. Not as severe as before, but I still have the problem.
>||| What's next?
>|||
>||| Thanks in advance for any assistance!
>|||
>||| Mark
>||| '98 TJ
>||| '98 XJ
>||
>|| Well, by cracky, it's fixed. It didn't come about without a
>|| story, though. I took off from work at noon yesterday (Friday)
>|| and set out to my local AutoZone store to drop about $150 on new
>|| oxygen sensors. En route, something happened that hadn't before.
>|| Specifically my "CHECK ENGINE" light came on. Now I KNEW that I
>|| had to have some sort of codes that would display (none did the
>|| previous day when my buddy plugged in his code reader). So,
>|| when I got to AutoZone, I asked the counter guy if he had a code
>|| reader, which he did. He checked it and got a code "TPS/Pedal
>|| Travel Sensor". Well, neither one of us knew what a Pedal
>|| Travel Sensor was, but both knew what a TPS was. However, the
>|| counter guy still suggests strongly that I've got a fuel filter
>|| problem and that should be my priority fix. I thanked him and
>|| decided that it was now time to go see the Jeep repair guy at a
>|| dealership. Drove crosstown and talked with the Jeep technician
>|| who really felt it was the throttle position sensor, so I went
>|| to their parts counter and asked if they had one. Nope, but
>|| they could order it. I had 'em check with a dealership 35 miles
>|| down the road. They had 3 of 'em. I got on the cellphone and
>|| asked them to hold one, I'd be right there. An hour later, I've
>|| got the new one on and everything is back to normal! Now I can
>|| get back to spending $$$ on my Jeep for fun things.
>||
>|| Thanks to everyone who provided assistance with this.
>||
>|| Mark
>|| '98 TJ
>|| '98 XJ
>|
>| Took a long ccruise with it yesterday. Ran just fine. Got home
>| and it started bucking severely as I was slowing to a stop. Kind
>| of like you didn't let the clutch out coming to a stop. It died,
>| but I was able to start it again. A few miles down the road, it
>| bucked again when taking off from a stop (this time, like letting
>| the clutch out too quickly when taking off). I got home with it
>| ok, tho. Today, it turns over but won't fire at all. What now?
>|
>| Mark
>
>
>I may have missed it, but how many miles are on it?

Just over 71,000. At this point, I'm thinking crank position sensor?

Mark

 

On Tue, 7 Sep 2004 02:08:33 UTC M. E. Bye <fxdyna@hotmail.com> wrote:

> Just over 71,000. At this point, I'm thinking crank position sensor?

I would be looking at cruddy connectors, myself, but when I first got
mine it was doing this and it took the whole arsenal and several
months to get a decent idle. Cleaning the TPS and throttle body made
the biggest difference - especially the port for the Idle Air Control
- but it took a new O2 sensor to get the last little dip out. Mine is
the older version MFI and it still wants to die when I hit the brake
just after starting and easing to the bottom of the hill. Now code
retention for the old beast but I'd go with the info you have and
check the connectors for the TPS.

Slightly different, but this may be a clue for some others: it now
appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
vacuum leak but it cures itself after the first time so it would
almost have to be a sticky check valve in there. Anyone know of a
check valve in the brake booster that can stick allowing a large
vavuum leak until it frees itself?

--
Will Honea

 

On Tue, 7 Sep 2004 02:08:33 UTC M. E. Bye <fxdyna@hotmail.com> wrote:

> Just over 71,000. At this point, I'm thinking crank position sensor?

I would be looking at cruddy connectors, myself, but when I first got
mine it was doing this and it took the whole arsenal and several
months to get a decent idle. Cleaning the TPS and throttle body made
the biggest difference - especially the port for the Idle Air Control
- but it took a new O2 sensor to get the last little dip out. Mine is
the older version MFI and it still wants to die when I hit the brake
just after starting and easing to the bottom of the hill. Now code
retention for the old beast but I'd go with the info you have and
check the connectors for the TPS.

Slightly different, but this may be a clue for some others: it now
appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
vacuum leak but it cures itself after the first time so it would
almost have to be a sticky check valve in there. Anyone know of a
check valve in the brake booster that can stick allowing a large
vavuum leak until it frees itself?

--
Will Honea

 

On Tue, 7 Sep 2004 02:08:33 UTC M. E. Bye <fxdyna@hotmail.com> wrote:

> Just over 71,000. At this point, I'm thinking crank position sensor?

I would be looking at cruddy connectors, myself, but when I first got
mine it was doing this and it took the whole arsenal and several
months to get a decent idle. Cleaning the TPS and throttle body made
the biggest difference - especially the port for the Idle Air Control
- but it took a new O2 sensor to get the last little dip out. Mine is
the older version MFI and it still wants to die when I hit the brake
just after starting and easing to the bottom of the hill. Now code
retention for the old beast but I'd go with the info you have and
check the connectors for the TPS.

Slightly different, but this may be a clue for some others: it now
appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
vacuum leak but it cures itself after the first time so it would
almost have to be a sticky check valve in there. Anyone know of a
check valve in the brake booster that can stick allowing a large
vavuum leak until it frees itself?

--
Will Honea

 

Will Honea did pass the time by typing:

> Slightly different, but this may be a clue for some others: it now
> appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
> vacuum leak but it cures itself after the first time so it would
> almost have to be a sticky check valve in there. Anyone know of a
> check valve in the brake booster that can stick allowing a large
> vavuum leak until it frees itself?

No check valve that I'm aware of. You could block the hose off
and test to see if it's electrical.

Have you stuck a vac gauge on the intake rail and watched it
as you drive/brake?

One of these comes in real handy for diagnosing vac problems.
http://www.jcwhitney.com/autoparts/P.../p-877/c-10101

--
DougW

 

Will Honea did pass the time by typing:

> Slightly different, but this may be a clue for some others: it now
> appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
> vacuum leak but it cures itself after the first time so it would
> almost have to be a sticky check valve in there. Anyone know of a
> check valve in the brake booster that can stick allowing a large
> vavuum leak until it frees itself?

No check valve that I'm aware of. You could block the hose off
and test to see if it's electrical.

Have you stuck a vac gauge on the intake rail and watched it
as you drive/brake?

One of these comes in real handy for diagnosing vac problems.
http://www.jcwhitney.com/autoparts/P.../p-877/c-10101

--
DougW

 

Will Honea did pass the time by typing:

> Slightly different, but this may be a clue for some others: it now
> appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
> vacuum leak but it cures itself after the first time so it would
> almost have to be a sticky check valve in there. Anyone know of a
> check valve in the brake booster that can stick allowing a large
> vavuum leak until it frees itself?

No check valve that I'm aware of. You could block the hose off
and test to see if it's electrical.

Have you stuck a vac gauge on the intake rail and watched it
as you drive/brake?

One of these comes in real handy for diagnosing vac problems.
http://www.jcwhitney.com/autoparts/P.../p-877/c-10101

--
DougW

 

On Tue, 7 Sep 2004 17:17:27 UTC "DougW" <post.replies@invalid.address>
wrote:

> Will Honea did pass the time by typing:
>
> > Slightly different, but this may be a clue for some others: it now
> > appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
> > vacuum leak but it cures itself after the first time so it would
> > almost have to be a sticky check valve in there. Anyone know of a
> > check valve in the brake booster that can stick allowing a large
> > vavuum leak until it frees itself?
>
> No check valve that I'm aware of. You could block the hose off
> and test to see if it's electrical.
>
> Have you stuck a vac gauge on the intake rail and watched it
> as you drive/brake?
>
> One of these comes in real handy for diagnosing vac problems.
> http://www.jcwhitney.com/autoparts/P.../p-877/c-10101

I haven't done anything - yet. I just noticed the brake/stumble
correlation this weekend and after learning to live with that "it's
gonna die at the first stop sign when the weather is just right" for
close to 60K miles it's not a priority. I remember chasing a couple
of Chrysler problems where the engine would die if you eased down on
the brake pedal and held it in just the right spot. That was a leak
in the brake booster but it was repeatable (once you figured out WTF
it was doing!) and it did not go away like this one does. GM's of the
80's were also bad about that leak but this one has real character so
I'll get around to it one of these days...



--
Will Honea

 

On Tue, 7 Sep 2004 17:17:27 UTC "DougW" <post.replies@invalid.address>
wrote:

> Will Honea did pass the time by typing:
>
> > Slightly different, but this may be a clue for some others: it now
> > appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
> > vacuum leak but it cures itself after the first time so it would
> > almost have to be a sticky check valve in there. Anyone know of a
> > check valve in the brake booster that can stick allowing a large
> > vavuum leak until it frees itself?
>
> No check valve that I'm aware of. You could block the hose off
> and test to see if it's electrical.
>
> Have you stuck a vac gauge on the intake rail and watched it
> as you drive/brake?
>
> One of these comes in real handy for diagnosing vac problems.
> http://www.jcwhitney.com/autoparts/P.../p-877/c-10101

I haven't done anything - yet. I just noticed the brake/stumble
correlation this weekend and after learning to live with that "it's
gonna die at the first stop sign when the weather is just right" for
close to 60K miles it's not a priority. I remember chasing a couple
of Chrysler problems where the engine would die if you eased down on
the brake pedal and held it in just the right spot. That was a leak
in the brake booster but it was repeatable (once you figured out WTF
it was doing!) and it did not go away like this one does. GM's of the
80's were also bad about that leak but this one has real character so
I'll get around to it one of these days...



--
Will Honea

 

On Tue, 7 Sep 2004 17:17:27 UTC "DougW" <post.replies@invalid.address>
wrote:

> Will Honea did pass the time by typing:
>
> > Slightly different, but this may be a clue for some others: it now
> > appears that mine dies WHEN I HIT THE BRAKE PEDAL. That points to a
> > vacuum leak but it cures itself after the first time so it would
> > almost have to be a sticky check valve in there. Anyone know of a
> > check valve in the brake booster that can stick allowing a large
> > vavuum leak until it frees itself?
>
> No check valve that I'm aware of. You could block the hose off
> and test to see if it's electrical.
>
> Have you stuck a vac gauge on the intake rail and watched it
> as you drive/brake?
>
> One of these comes in real handy for diagnosing vac problems.
> http://www.jcwhitney.com/autoparts/P.../p-877/c-10101

I haven't done anything - yet. I just noticed the brake/stumble
correlation this weekend and after learning to live with that "it's
gonna die at the first stop sign when the weather is just right" for
close to 60K miles it's not a priority. I remember chasing a couple
of Chrysler problems where the engine would die if you eased down on
the brake pedal and held it in just the right spot. That was a leak
in the brake booster but it was repeatable (once you figured out WTF
it was doing!) and it did not go away like this one does. GM's of the
80's were also bad about that leak but this one has real character so
I'll get around to it one of these days...



--
Will Honea