Hi all,

I've been having a minor problem with my jeep since I bought it. It
always had a stinky smell to the exhaust like it's running rich. I replaced
the O2 sensor but that did not help. Today I looked at the stepper motor on
the back of my Carb. The test I did was to choke it out by holding my hand
over the carb while running and then view the metering pins when I removed
my hand. From what I read they should be moving, adjusting to compensate
for the choke. The pins did not move at all. I had cleaned the metering
pin's housing eariler in the day with carb cleaner. They were gummy and did
not move with ease before I cleaned them. After which, they moved fine
manually but did not move when running.

Questions:

How can I diagnosis if the problem is with the stepper motor or another
part?
If the problem is with the stepper motor can I purchase and replace only
that part or do I need to buy a kit?
Where can I purchase a stepper motor and is there another name for it (the
parts stores I went to didn't know what I was talking about).


Thanks in advance,

Bill

 

Many of your questions will be answered from this YJ site:
http://home.sprynet.com/~dale02/list.htm
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

William Oliveri wrote:
>
> BTW, my jeep is a 83 CJ7, 258 I6.
>
> Thanks again.
>
> Bill
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:betjvh$8jaf8$1@ID-193866.news.uni-berlin.de...
> > Hi all,
> >
> > I've been having a minor problem with my jeep since I bought it. It
> > always had a stinky smell to the exhaust like it's running rich. I
> replaced
> > the O2 sensor but that did not help. Today I looked at the stepper motor
> on
> > the back of my Carb. The test I did was to choke it out by holding my
> hand
> > over the carb while running and then view the metering pins when I removed
> > my hand. From what I read they should be moving, adjusting to compensate
> > for the choke. The pins did not move at all. I had cleaned the metering
> > pin's housing eariler in the day with carb cleaner. They were gummy and
> did
> > not move with ease before I cleaned them. After which, they moved fine
> > manually but did not move when running.
> >
> > Questions:
> >
> > How can I diagnosis if the problem is with the stepper motor or another
> > part?
> > If the problem is with the stepper motor can I purchase and replace only
> > that part or do I need to buy a kit?
> > Where can I purchase a stepper motor and is there another name for it (the
> > parts stores I went to didn't know what I was talking about).
> >
> >
> > Thanks in advance,
> >
> > Bill
> >
> >

 

I forget which year Jeep started using the computer controlled BBD but are
you sure the prev owner didn't mod it with the Nutter Bypass? The stepper
wouldn't move if he (or she...pardon Jo and Jen) put the idiot box to sleep.

> From: "William Oliveri" <wuji@bigvalley.net>
> Newsgroups: rec.autos.makers.jeep+******
> Date: Sun, 13 Jul 2003 23:52:31 -0700
> Subject: Stepper Motor Bad?
>
> Hi all,
>
> I've been having a minor problem with my jeep since I bought it. It
> always had a stinky smell to the exhaust like it's running rich. I replaced
> the O2 sensor but that did not help. Today I looked at the stepper motor on
> the back of my Carb. The test I did was to choke it out by holding my hand
> over the carb while running and then view the metering pins when I removed
> my hand. From what I read they should be moving, adjusting to compensate
> for the choke. The pins did not move at all. I had cleaned the metering
> pin's housing eariler in the day with carb cleaner. They were gummy and did
> not move with ease before I cleaned them. After which, they moved fine
> manually but did not move when running.
>
> Questions:
>
> How can I diagnosis if the problem is with the stepper motor or another
> part?
> If the problem is with the stepper motor can I purchase and replace only
> that part or do I need to buy a kit?
> Where can I purchase a stepper motor and is there another name for it (the
> parts stores I went to didn't know what I was talking about).
>
>
> Thanks in advance,
>
> Bill
>
>

 

Interesting. So it would be a good idea to pull the connector at the MCU
after doing the bypass. Good to know.

> From: Mike Romain <romainm@sympatico.ca>
> Organization: Bell Sympatico
> Newsgroups: rec.autos.makers.jeep+******
> Date: Tue, 15 Jul 2003 11:11:12 -0400
> Subject: Re: Stepper Motor Bad?
>
> I would be wondering the same as Kurt...
>
> One sure way to tell is to look at the ignition module way down under
> the washer bottle. Check the purple wire coming off on one of the
> plugs. If the purple wire is connected, the computer is bypassed.
>
> A short inside the MCU can still cause tons of trouble, even if it isn't
> controlling the timing. Mine went bad after the Nutter and killed my
> pickup coil and ignition module. The Jeep shop had it at that point
> because it was 'their' new engine I couldn't make run after it's first
> 1/2 hour run up and they had to snip some more wires to get the computer
> totally out or to at least prevent it from interacting at all.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
>>
>> No, the previous owner didn't do the Nutter. I know this because:
>>
>> 1. After I bought it the MCU died and I had to replace it. If the prev
>> owner did the Nutter I wouldn't of had to replace the MCU.
>>
>> 2. I was thinking of doing the Nutter Bypass and I've inspected it before I
>> did. It's all hooked up as stock (no bypass).
>>
>> I think the first year was mine (83 CJ)
>>
>> Thanks,
>>
>> Bill
>>
>> "KurtS" <nospam@thanksImFull.spam> wrote in message
>> news:BB389932.1A80F%nospam@thanksImFull.spam...
>>> I forget which year Jeep started using the computer controlled BBD but are
>>> you sure the prev owner didn't mod it with the Nutter Bypass? The stepper
>>> wouldn't move if he (or she...pardon Jo and Jen) put the idiot box to
>> sleep.
>>>
>>>> From: "William Oliveri" <wuji@bigvalley.net>
>>>> Newsgroups: rec.autos.makers.jeep+******
>>>> Date: Sun, 13 Jul 2003 23:52:31 -0700
>>>> Subject: Stepper Motor Bad?
>>>>
>>>> Hi all,
>>>>
>>>> I've been having a minor problem with my jeep since I bought it. It
>>>> always had a stinky smell to the exhaust like it's running rich. I
>> replaced
>>>> the O2 sensor but that did not help. Today I looked at the stepper
>> motor on
>>>> the back of my Carb. The test I did was to choke it out by holding my
>> hand
>>>> over the carb while running and then view the metering pins when I
>> removed
>>>> my hand. From what I read they should be moving, adjusting to
>> compensate
>>>> for the choke. The pins did not move at all. I had cleaned the
>> metering
>>>> pin's housing eariler in the day with carb cleaner. They were gummy and
>> did
>>>> not move with ease before I cleaned them. After which, they moved fine
>>>> manually but did not move when running.
>>>>
>>>> Questions:
>>>>
>>>> How can I diagnosis if the problem is with the stepper motor or another
>>>> part?
>>>> If the problem is with the stepper motor can I purchase and replace only
>>>> that part or do I need to buy a kit?
>>>> Where can I purchase a stepper motor and is there another name for it
>> (the
>>>> parts stores I went to didn't know what I was talking about).
>>>>
>>>>
>>>> Thanks in advance,
>>>>
>>>> Bill
>>>>
>>>>
>>>

 

The tach feed comes from the MCU on a YJ, so the tach wire would need to
be moved to the coil.

Not an issue on a CJ7, it's tach is inline with the ignition module
power.

Mike

KurtS wrote:
>
> Interesting. So it would be a good idea to pull the connector at the MCU
> after doing the bypass. Good to know.
>
> > From: Mike Romain <romainm@sympatico.ca>
> > Organization: Bell Sympatico
> > Newsgroups: rec.autos.makers.jeep+******
> > Date: Tue, 15 Jul 2003 11:11:12 -0400
> > Subject: Re: Stepper Motor Bad?
> >
> > I would be wondering the same as Kurt...
> >
> > One sure way to tell is to look at the ignition module way down under
> > the washer bottle. Check the purple wire coming off on one of the
> > plugs. If the purple wire is connected, the computer is bypassed.
> >
> > A short inside the MCU can still cause tons of trouble, even if it isn't
> > controlling the timing. Mine went bad after the Nutter and killed my
> > pickup coil and ignition module. The Jeep shop had it at that point
> > because it was 'their' new engine I couldn't make run after it's first
> > 1/2 hour run up and they had to snip some more wires to get the computer
> > totally out or to at least prevent it from interacting at all.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > William Oliveri wrote:
> >>
> >> No, the previous owner didn't do the Nutter. I know this because:
> >>
> >> 1. After I bought it the MCU died and I had to replace it. If the prev
> >> owner did the Nutter I wouldn't of had to replace the MCU.
> >>
> >> 2. I was thinking of doing the Nutter Bypass and I've inspected it before I
> >> did. It's all hooked up as stock (no bypass).
> >>
> >> I think the first year was mine (83 CJ)
> >>
> >> Thanks,
> >>
> >> Bill
> >>
> >> "KurtS" <nospam@thanksImFull.spam> wrote in message
> >> news:BB389932.1A80F%nospam@thanksImFull.spam...
> >>> I forget which year Jeep started using the computer controlled BBD but are
> >>> you sure the prev owner didn't mod it with the Nutter Bypass? The stepper
> >>> wouldn't move if he (or she...pardon Jo and Jen) put the idiot box to
> >> sleep.
> >>>
> >>>> From: "William Oliveri" <wuji@bigvalley.net>
> >>>> Newsgroups: rec.autos.makers.jeep+******
> >>>> Date: Sun, 13 Jul 2003 23:52:31 -0700
> >>>> Subject: Stepper Motor Bad?
> >>>>
> >>>> Hi all,
> >>>>
> >>>> I've been having a minor problem with my jeep since I bought it. It
> >>>> always had a stinky smell to the exhaust like it's running rich. I
> >> replaced
> >>>> the O2 sensor but that did not help. Today I looked at the stepper
> >> motor on
> >>>> the back of my Carb. The test I did was to choke it out by holding my
> >> hand
> >>>> over the carb while running and then view the metering pins when I
> >> removed
> >>>> my hand. From what I read they should be moving, adjusting to
> >> compensate
> >>>> for the choke. The pins did not move at all. I had cleaned the
> >> metering
> >>>> pin's housing eariler in the day with carb cleaner. They were gummy and
> >> did
> >>>> not move with ease before I cleaned them. After which, they moved fine
> >>>> manually but did not move when running.
> >>>>
> >>>> Questions:
> >>>>
> >>>> How can I diagnosis if the problem is with the stepper motor or another
> >>>> part?
> >>>> If the problem is with the stepper motor can I purchase and replace only
> >>>> that part or do I need to buy a kit?
> >>>> Where can I purchase a stepper motor and is there another name for it
> >> (the
> >>>> parts stores I went to didn't know what I was talking about).
> >>>>
> >>>>
> >>>> Thanks in advance,
> >>>>
> >>>> Bill
> >>>>
> >>>>
> >>>