Help! Jeep Cherokee can't go over 20mph!!!

James Morr

Help! Jeep Cherokee can't go over 20mph!!!

by James Morr » Wed, 03 Sep 2003 15:19:32

Hey everyone! I need some help. Ok, the long and short of it is that
my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6 and
it's an automatic.

Now, 3 days ago it was fine. Everything ran great. Then, I decided
that I wanted a better air intake system, so I disconnected the filter
housing from the intake arm and stuck a cone filter on the end of the
arm. I relocated the CCV hoses to the intake arm, but nothing else. At
first it seemed to give a noticable power gain and much more
aggressive tone. Then, over the next three days, it has been gradually
slowing down. The engine will still rev just as hard as ever, but I
can be in 4th gear on a straightaway at 5k/rpm and I'll only be going
25 or 30mph. Now, I thought that I might have messed somehthing up
when I modified the intake system, so, I took off the cone filter and
put the stock housing back in. No such luck! However, during the
intake modification I lost the caps off of a couple of the vaccum
hoses (2 that run to the back of the air cleaner housing & other misc)
so they are not currently hooked up. Everyone I know says that they're
not sure what the problem is but that disconnected vaccum hoses would
not cause any problems of the sort. Several also say that the timing
is just a coincidence and that the air intake system would have
nothing to do with my problem. They say it sounds like a *** issue.
Do you think maybe I messed up a sensor and the computer's ratios are
messed up? Has anyone ever heard of a problem like this happening
before? I tried searching the internet but I couldn't find anything
related to my problem mainly because I have no clue what is causing
it. If anyone has any insight as to what is wrong with my Jeep I would
really appreciate the help. It's my baby and I just wanna get it
runnnin right again asap. Thanks!

James Morrow

Joseph Oberlande

Help! Jeep Cherokee can't go over 20mph!!!

by Joseph Oberlande » Wed, 03 Sep 2003 16:32:25


> nothing to do with my problem. They say it sounds like a *** issue.

Yep.  ***.  It is likely unrelated.  Mine just went out last time
with about 3 blocks warning.  Fine fine fine fine - dead as a rock.
Well, it did run - but maybe 20mph in 1st gear.  For a few days, then
it gave out as well.   In your case, it may be that you got jammed in
4-Low.  Of course a new transfer case or transmission?  $$$$.

15 years old?  Yeah - probably time for it to die the second time.

My recommedation - time to look into getting a new vehicle.

Bill Kapa

Help! Jeep Cherokee can't go over 20mph!!!

by Bill Kapa » Wed, 03 Sep 2003 18:58:50



>Hey everyone! I need some help. Ok, the long and short of it is that
>my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6 and
>it's an automatic.

>Now, 3 days ago it was fine. Everything ran great. Then, I decided
>that I wanted a better air intake system, so I disconnected the filter
>housing from the intake arm and stuck a cone filter on the end of the
>arm. I relocated the CCV hoses to the intake arm, but nothing else. At
>first it seemed to give a noticable power gain and much more
>aggressive tone. Then, over the next three days, it has been gradually
>slowing down. The engine will still rev just as hard as ever, but I
>can be in 4th gear on a straightaway at 5k/rpm and I'll only be going
>25 or 30mph. Now, I thought that I might have messed somehthing up
>when I modified the intake system, so, I took off the cone filter and
>put the stock housing back in. No such luck! However, during the
>intake modification I lost the caps off of a couple of the vaccum
>hoses (2 that run to the back of the air cleaner housing & other misc)
>so they are not currently hooked up. Everyone I know says that they're
>not sure what the problem is but that disconnected vaccum hoses would
>not cause any problems of the sort. Several also say that the timing
>is just a coincidence and that the air intake system would have
>nothing to do with my problem. They say it sounds like a *** issue.
>Do you think maybe I messed up a sensor and the computer's ratios are
>messed up? Has anyone ever heard of a problem like this happening
>before? I tried searching the internet but I couldn't find anything
>related to my problem mainly because I have no clue what is causing
>it. If anyone has any insight as to what is wrong with my Jeep I would
>really appreciate the help. It's my baby and I just wanna get it
>runnnin right again asap. Thanks!

>James Morrow

I don't know if your transmission has a vacuum modulator or not, but if it
does AND it's not getting vacuum, it won't upshift.
It senses engine load by the amount of vacuum (low vacuum, heavy
load--high vacuum, light load). It "thinks" the engine is lugged down.
Wildma

Help! Jeep Cherokee can't go over 20mph!!!

by Wildma » Wed, 03 Sep 2003 18:48:14

Make sure your catalytic converter is not plugged. My 93 XJ had the same
problem. I thought it was a *** issue, but it boiled down to a plugged
converter.

Mike Romai

Help! Jeep Cherokee can't go over 20mph!!!

by Mike Romai » Wed, 03 Sep 2003 22:26:08

You have a mechanical kick down at the throttle body and a TPS that
controls the shifting.

I would be suspecting one of those first.

Even with vacuum leaks it should shift.   Vacuum leaks aren't a good
thing though.  I use a chunk of hose with a bolt in it for a cap if I
have misplaced the *** ones.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's


> Hey everyone! I need some help. Ok, the long and short of it is that
> my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6 and
> it's an automatic.

> Now, 3 days ago it was fine. Everything ran great. Then, I decided
> that I wanted a better air intake system, so I disconnected the filter
> housing from the intake arm and stuck a cone filter on the end of the
> arm. I relocated the CCV hoses to the intake arm, but nothing else. At
> first it seemed to give a noticable power gain and much more
> aggressive tone. Then, over the next three days, it has been gradually
> slowing down. The engine will still rev just as hard as ever, but I
> can be in 4th gear on a straightaway at 5k/rpm and I'll only be going
> 25 or 30mph. Now, I thought that I might have messed somehthing up
> when I modified the intake system, so, I took off the cone filter and
> put the stock housing back in. No such luck! However, during the
> intake modification I lost the caps off of a couple of the vaccum
> hoses (2 that run to the back of the air cleaner housing & other misc)
> so they are not currently hooked up. Everyone I know says that they're
> not sure what the problem is but that disconnected vaccum hoses would
> not cause any problems of the sort. Several also say that the timing
> is just a coincidence and that the air intake system would have
> nothing to do with my problem. They say it sounds like a *** issue.
> Do you think maybe I messed up a sensor and the computer's ratios are
> messed up? Has anyone ever heard of a problem like this happening
> before? I tried searching the internet but I couldn't find anything
> related to my problem mainly because I have no clue what is causing
> it. If anyone has any insight as to what is wrong with my Jeep I would
> really appreciate the help. It's my baby and I just wanna get it
> runnnin right again asap. Thanks!

> James Morrow

Chris Z

Help! Jeep Cherokee can't go over 20mph!!!

by Chris Z » Thu, 04 Sep 2003 00:32:15


Did you bother to check the transmission fluid level when this started to
happen?  If not, and it's low enough to cause this much slipping, I'd guess
there's a good chance you killed the *** by continuing to drive it this
way.

Chris

Daniel J. Ster

Help! Jeep Cherokee can't go over 20mph!!!

by Daniel J. Ster » Thu, 04 Sep 2003 01:02:03


This is not "better" in any way, shape or form.

The power gain was your imagination (or your having replaced a dirty stock
filter with a clean cone), aided and abetted by your ears hearing the
intake roar.

Sounds like bigtime transmission slippage. Checked your transmission
fluid...lately? Do so now. What's it smell like?

Probably not causing your problem, but also not something to just shrug
and say "Whatever..." about. Those hoses are there for a reason. Fix 'em!

The computer has no ratios.

DS

Brandy Woo

Help! Jeep Cherokee can't go over 20mph!!!

by Brandy Woo » Thu, 04 Sep 2003 09:31:59

Try the catalic converter, or the bands on the *** are slipping.  try
Jose martinez outta trumbell tx,  heres the number 972-544-3267  he's the
cheapest out there with a greatest warranty.
bw

Dan Lefrancoi

Help! Jeep Cherokee can't go over 20mph!!!

by Dan Lefrancoi » Thu, 04 Sep 2003 16:05:52

: Hey everyone! I need some help. Ok, the long and short of it is that
: my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6 and
: it's an automatic.

: Now, 3 days ago it was fine. Everything ran great. Then, I decided
: that I wanted a better air intake system, so I disconnected the filter

I had a very very similar problem (although not caused by any mechanical
changes). I thought my *** was a goner. Turns out it was the TPS
sensor. Simple to fix. I'd recommend you try this first, before looking at
the ***.

Dan

Clem

Help! Jeep Cherokee can't go over 20mph!!!

by Clem » Sat, 06 Sep 2003 06:11:17

4th gear and 5k rpm and 20 mph?

You have serious *** problems.


Clem

Help! Jeep Cherokee can't go over 20mph!!!

by Clem » Sat, 06 Sep 2003 06:13:11

'88 was still amc.. too bad.

If it was chrysler you could scan the computer very easily for codes, which
would tell you whether it's the TPS or not.

AMC is probably scannable... check out www.batauto.com and find the trouble
code section.


Kevin in San Dieg

Help! Jeep Cherokee can't go over 20mph!!!

by Kevin in San Dieg » Sat, 06 Sep 2003 12:22:24

No the 88 isnt really scannable. I dont think you can even find a daignostic
tool for the port on that thing.
KH


> '88 was still amc.. too bad.

> If it was chrysler you could scan the computer very easily for codes,
which
> would tell you whether it's the TPS or not.

> AMC is probably scannable... check out www.batauto.com and find the
trouble
> code section.



> > : Hey everyone! I need some help. Ok, the long and short of it is that
> > : my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6 and
> > : it's an automatic.

> > : Now, 3 days ago it was fine. Everything ran great. Then, I decided
> > : that I wanted a better air intake system, so I disconnected the filter

> > I had a very very similar problem (although not caused by any mechanical
> > changes). I thought my *** was a goner. Turns out it was the TPS
> > sensor. Simple to fix. I'd recommend you try this first, before looking
at
> > the ***.

> > Dan

Dave

Help! Jeep Cherokee can't go over 20mph!!!

by Dave » Sat, 06 Sep 2003 21:28:40

Yes Bendix made testers that the Jeep dealers used to hook up to the 88 XJs.
Snap on also makes adapters that will work too.
later,
dave (with the Bendix)
88 XJ



> No the 88 isnt really scannable. I dont think you can even find a
daignostic
> tool for the port on that thing.
> KH



> > '88 was still amc.. too bad.

> > If it was chrysler you could scan the computer very easily for codes,
> which
> > would tell you whether it's the TPS or not.

> > AMC is probably scannable... check out www.batauto.com and find the
> trouble
> > code section.



> > > : Hey everyone! I need some help. Ok, the long and short of it is that
> > > : my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6
and
> > > : it's an automatic.

> > > : Now, 3 days ago it was fine. Everything ran great. Then, I decided
> > > : that I wanted a better air intake system, so I disconnected the
filter

> > > I had a very very similar problem (although not caused by any
mechanical
> > > changes). I thought my *** was a goner. Turns out it was the TPS
> > > sensor. Simple to fix. I'd recommend you try this first, before
looking
> at
> > > the ***.

> > > Dan

Mike Romai

Help! Jeep Cherokee can't go over 20mph!!!

by Mike Romai » Sat, 06 Sep 2003 22:25:26

My book says a DRB 11 tool can read the 88's.  The V6's had a self
diagnostics and 91 to 97 have them.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's


> No the 88 isnt really scannable. I dont think you can even find a daignostic
> tool for the port on that thing.
> KH



> > '88 was still amc.. too bad.

> > If it was chrysler you could scan the computer very easily for codes,
> which
> > would tell you whether it's the TPS or not.

> > AMC is probably scannable... check out www.batauto.com and find the
> trouble
> > code section.



> > > : Hey everyone! I need some help. Ok, the long and short of it is that
> > > : my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6 and
> > > : it's an automatic.

> > > : Now, 3 days ago it was fine. Everything ran great. Then, I decided
> > > : that I wanted a better air intake system, so I disconnected the filter

> > > I had a very very similar problem (although not caused by any mechanical
> > > changes). I thought my *** was a goner. Turns out it was the TPS
> > > sensor. Simple to fix. I'd recommend you try this first, before looking
> at
> > > the ***.

> > > Dan

greg pabs

Help! Jeep Cherokee can't go over 20mph!!!

by greg pabs » Sat, 06 Sep 2003 22:36:28

I also had the same symptoms, and also thought it was a transmission problem,
and it turned out to be the catalytic converter

> Yes Bendix made testers that the Jeep dealers used to hook up to the 88 XJs.
> Snap on also makes adapters that will work too.
> later,
> dave (with the Bendix)
> 88 XJ



> > No the 88 isnt really scannable. I dont think you can even find a
> daignostic
> > tool for the port on that thing.
> > KH



> > > '88 was still amc.. too bad.

> > > If it was chrysler you could scan the computer very easily for codes,
> > which
> > > would tell you whether it's the TPS or not.

> > > AMC is probably scannable... check out www.batauto.com and find the
> > trouble
> > > code section.



> > > > : Hey everyone! I need some help. Ok, the long and short of it is that
> > > > : my 88 Jeep Cherokee Pioneer won't go over 20mph. It has the 4.0 L6
> and
> > > > : it's an automatic.

> > > > : Now, 3 days ago it was fine. Everything ran great. Then, I decided
> > > > : that I wanted a better air intake system, so I disconnected the
> filter

> > > > I had a very very similar problem (although not caused by any
> mechanical
> > > > changes). I thought my *** was a goner. Turns out it was the TPS
> > > > sensor. Simple to fix. I'd recommend you try this first, before
> looking
> > at
> > > > the ***.

> > > > Dan