Running Rich - 92-4.0L
 

I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
smoke from exhaust.

I put a new O2 sensor in a month ago, but it is still running rich. I have
gone through and cleaned out the TB, and TPS & AIC sensors, still rich.

What else could cause this?

Re: Running Rich - 92-4.0L
 

Les wrote:
> I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black,
> black smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I
> have gone through and cleaned out the TB, and TPS & AIC sensors,
> still rich.
>
> What else could cause this?

Cheap ones first.
- loose or broken vac line to the fuel pressure regulator?
That results in too high a fuel pressure under normal operation.
- Or too low a heat range on the plugs.
If they are running cold they will soot up.

Bad coil/weak spark that's not igniting each charge and letting some of
the fuel through. leaking injectors (but usually that's only on one cyl).
Clogged cat can result in backpressure problems.

Any fault codes?
http://autorepair.about.com/library/...l-dtcs-24a.htm

--
DougW

Re: Running Rich - 92-4.0L
 

Les wrote:
> I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black,
> black smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I
> have gone through and cleaned out the TB, and TPS & AIC sensors,
> still rich.
>
> What else could cause this?

Cheap ones first.
- loose or broken vac line to the fuel pressure regulator?
That results in too high a fuel pressure under normal operation.
- Or too low a heat range on the plugs.
If they are running cold they will soot up.

Bad coil/weak spark that's not igniting each charge and letting some of
the fuel through. leaking injectors (but usually that's only on one cyl).
Clogged cat can result in backpressure problems.

Any fault codes?
http://autorepair.about.com/library/...l-dtcs-24a.htm

--
DougW

Re: Running Rich - 92-4.0L
 

Les wrote:
> I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black,
> black smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I
> have gone through and cleaned out the TB, and TPS & AIC sensors,
> still rich.
>
> What else could cause this?

Cheap ones first.
- loose or broken vac line to the fuel pressure regulator?
That results in too high a fuel pressure under normal operation.
- Or too low a heat range on the plugs.
If they are running cold they will soot up.

Bad coil/weak spark that's not igniting each charge and letting some of
the fuel through. leaking injectors (but usually that's only on one cyl).
Clogged cat can result in backpressure problems.

Any fault codes?
http://autorepair.about.com/library/...l-dtcs-24a.htm

--
DougW

Re: Running Rich - 92-4.0L
 

Intake air temp sensor.

Spdloader



"Les" <nospam@nospam.com> wrote in message
news:C15E3FE0.B334%nospam@nospam.com...
>I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
> smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I have
> gone through and cleaned out the TB, and TPS & AIC sensors, still rich.
>
> What else could cause this?
>

Re: Running Rich - 92-4.0L
 

Intake air temp sensor.

Spdloader



"Les" <nospam@nospam.com> wrote in message
news:C15E3FE0.B334%nospam@nospam.com...
>I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
> smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I have
> gone through and cleaned out the TB, and TPS & AIC sensors, still rich.
>
> What else could cause this?
>

Re: Running Rich - 92-4.0L
 

Intake air temp sensor.

Spdloader



"Les" <nospam@nospam.com> wrote in message
news:C15E3FE0.B334%nospam@nospam.com...
>I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
> smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I have
> gone through and cleaned out the TB, and TPS & AIC sensors, still rich.
>
> What else could cause this?
>

Re: Running Rich - 92-4.0L
 

A dirty air filter?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Les wrote:
>
> I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
> smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I have
> gone through and cleaned out the TB, and TPS & AIC sensors, still rich.
>
> What else could cause this?

Re: Running Rich - 92-4.0L
 

A dirty air filter?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Les wrote:
>
> I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
> smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I have
> gone through and cleaned out the TB, and TPS & AIC sensors, still rich.
>
> What else could cause this?

Re: Running Rich - 92-4.0L
 

A dirty air filter?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Les wrote:
>
> I have a 92 Wrangler, 4.0L that is running real rich. Plugs go black, black
> smoke from exhaust.
>
> I put a new O2 sensor in a month ago, but it is still running rich. I have
> gone through and cleaned out the TB, and TPS & AIC sensors, still rich.
>
> What else could cause this?