These pages are intended for those
like myself who live in states where an annual
is required to get license tags, and for those
who are just plain mystified
when they look under the hood and wonder what all that
There is some
technical information here, but the mechanically
challenged like myself will find easy explanations for
most of the emissions freedenoids under the hood, and for
the operation of the evil computer.
I hope someone else can benefit from
what I've learned trying to keep my 258 Jeep running.
This information was gathered from the Web, the original
Service Manual, anyone who would talk to me, and from my
own experience trying to figure out why mine was running
so badly after only 13 years of neglect.
This information applies to my
1985 AMC 258 six-cylinder Jeep CJ-7
with 5-speed manual transmission, and with all
stock factory emission-control gear in place and
operating. I believe it applies to
258 CID Jeeps from 1983 to 1986 and, with minor
differences, to 258 Wranglers from 1987 to 1990. If you
vehemently disagree with anything I've included here,
I'll be glad to talk about it if you're polite.
In boxes like this, look for "Quick and Dirty" checks
that can be done with little or no test equipment.
I couldn't resist including this picture of my 1985 CJ-7,
taken when it was less than a week old. The paint was
"Bronze Mica-tallic", looked fabulous when it
was new, but hasn't weathered too well. It came with a
nutmeg hardtop, which I removed. You understand...
probably don't have to tell you that it doesn't look this
good right now. What a blessing, having a rust-colored
Jeep® is a
registered trademark of FCA US LLC®, with which I am
not affiliated in any way.
If you decide to act on any information provided here, you do so at your own risk.
It is your responsibility to use safe procedures if working on your vehicle, such as
the wearing of appropriate clothing and safety glasses, and being mindful of mechanical, electrical
and fire hazards while working with a gasoline engine. I am in no way responsible for
any torment you may suffer as a result of your acting on any information found here.
Updated Jan 31, 2020
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