"JeffD." wrote:
>
> > >
> > > > A plugged up air filter on the gas tank vent will cause symptoms like
> > > > that.
> > > >
> > > > Mike
> > > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > > 88 Cherokee 235 BFG AT's
> > > >
> > > > "JeffD." wrote:
> > > > >
> > > > > Good morning. Well, I posted here a few weeks ago with an unknown issue
> > > > > that I thought might be the transmission. It was diagnosed by those here
> > > > > and a tranny shop as other issues. At the recommendation of the shop, I
> > > > > replaced cap/rotor, I had just done plugs and wires and skipped those
> > > > > for now. At the advice of this group, I replaced the fuel filter, that
> > > > > seemed to have done the trick. Now my problem is back.
> > > > >
> > > > > I'll describe it as I did before, at highway speeds only, I get a
> > > > > hesitation. It feels like all the power just drops out of the engine. I
> > > > > get no spike up or down in oil pressure, voltage, rpm or temp. I have no
> > > > > check engine lights flashing or staying on and no other idiot lights
> > > > > showing. What I feel is something like pulling a trailer with electric
> > > > > brakes that all of a sudden start pulsing. It only happens at highway
> > > > > speeds and typically only after 20-30 minutes of driving.
> > > > >
> > > > > Any thoughts?? I did check the ground strap and see no
> > > > > rust/decay/fraying.
> > > > >
> > > > > Thanks.
> > >
> > > OK, that kind of makes some sense. Another issue, not described makes
> > > this seem even more likely. When I remove the cap to fill the tank, I
> > > often get a lengthy vapor pressure discharge. Where is the air filter
> > > for the vent hose?
> >
> > It is under the hood and is on the bottom of the charcoal canister. The
> > canister looks like a coffee can with tubes out the top. It is a $2.00
> > filter and is a real pain to change. The canister doesn't come apart so
> > the filter has to be dug out. The second one is easy though...
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
>
> Must bang head against brick wall! Forgot to mention it's a 92 XJ, 4.0
> FI HO. It appears that the evap canister is a single molded plastic
> unit, not the coffee can style. Next thoughts?

I guess they didn't like it that we could just change the two buck
filter eh.

I would be taking the tube off that goes from the canister to the air
filter box and be seeing if I could blow or suck through it with the gas
cap open.

On mine I check the filter by driving with the gas cap loose. If the
hesitation goes away, bingo. Mine doesn't have a check engine light to
go off though.

Mike