When only one is clogged, the computer will try and take an average of
the two.

It doesn't surprise me to have a bad reman out of the box. Happens
regularly, way more often that I'm happy with.

The Reverend Natural Light wrote:

> Joe C,
>
> After all my dumbass troubleshooting, I went ahead and followed the
> instructions to clear the idle tubes. Forget sludge in the tubes, one
> of them had a huge chunk of metal stuck in it! I pulled the chunk out,
> put the carb back together, and it runs great! This was a rebuilt carb
> fresh from the parts store!!
>
> Note to others: From all the notes I could find, clogged idle tubes
> were supposed to look like a rich condition. Not in this case! It ran
> like it had a horrible vacuum leak.
>
> Thanks!
>
> -rev
>
>
> Oh, and apparantly someone already invented the old model ignition
> module in the new model engine - it's called the "Nutter Bypass" and
> there are far easier ways to do it.
>
>
>
>
> The Reverend Natural Light wrote:
>
>>Greetings.
>>
>>I'm working on a 1990 Jeep YJ, 4.2L I6, that won't idle. From 1200RPM
>>up, everything's fine. It runs smooth under power. It won't idle at
>>all.
>>
>>The previous owner replaced the carb with an older non-computer
>>controlled unit. He made the decision to use the older carb because it
>>was cheaper and simpler and someone knowledgeable (?) told him to. I
>>believe it never ran right while he owned it.
>>
>>I have:
>>
>>1. Checked for vacuum leaks.
>>2. Made sure the EGR valve is completely closed.
>>3. Replaced spark plugs and checked cap and rotor (old plugs were worn
>>but tan).
>>4. Verified functional vacuum advance function.
>>5. Verified electric choke function.
>>6. Tried various settings of the idle bleed screws. Currently 2 turns
>>out.
>>
>>No help.
>>
>>Since it has an ECM controlling spark but no electronic carb, I figured
>>the computer controlled spark could be an issue. So, I picked up a new
>>spark control module for a non-ECM jeep and wired it up to the
>>distributor following the wiring diagram for an older jeep. Now there
>>is no computer control whatsoever.
>>
>>No help with idle, but the throttle response seems a bit crisper.
>>
>>
>>It appears to be running lean at closed-throttle because it will idle
>>if I manually close the choke flapper. This leads me to believe that
>>the problem is not the common "idle tubes" issue which causes a rich
>>condition. It really feels like a bad vacuum leak but I can't find it.
>>
>>
>>I'm completely out of ideas. In all honesty, I'm a lot more
>>comfortable working on fuel injection. A grizzled Jeep veteran could
>>probably whack it with a hammer and it would purr like a kitten. Any
>>advice?
>>
>>Thanks!
>>
>>
>>-rev
>
>