The first thing I did way back when was replace the O2 sensor as I didn't know how old it was. Couldn't find any record of it having been changed. Replacing it had no effect. However I don't know if there is an issue in the O2-ECU circuit. Not exactly sure where to begin with checking it with a dvom. The running/stumbling problem is not a deal breaker so I only work on it occasionally 

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> On Dec 7, 2016, at 10:07 AM, John Goubeaux <john@UCSB.EDU> wrote:
> 
> Thanks, Since I've recently replaced the fuel tank, all the hoses and
> grommets and lines and FP I'm gonna assume, unless i have bad fuel, that
> the fuel supply is not the issue.
> 
> I'm wondering though if the fuel pressure regulator can be intermittent
> ? OR if it just goes all at once ? My understanding is that when it goes
> the engine will run very rich as a result of the increase in pressure.
> 
> 
>> On 12/7/16 9:41 AM, Don Hanson wrote:
>> 
>> Water in the gas tank?   Just did that... the expansion tank rubber
>> grommets on my 84 were useless, and those expansion tanks are
>> perfectly positioned in the wheel wells to collect water on their flat
>> tops, with tubes to take that collected water back into the main tank.
>>    I surmised that as long as you're moving and the engine is
>> running, the water in the gas is all mixed up and doesn't hurt the
>> running but when you shut down for a while, the water that was in
>> solution with the gas settles out, then when you start again, you get
>> mostly water to run the motor..
>>  I don't know if mine "seemed" to "show" rich symptoms, but bad gas
>> and rich are similar in manifested symptoms...
>> 
>> 
>> On Dec 7, 2016 8:51 AM, "John Goubeaux" <john@ucsb.edu
>> <mailto:john@ucsb.edu>> wrote:
>> 
>>    In my case I've already replaced both the AFM and TB with rebuilt ones
>>    and had them adjusted, so I'm gonna rule them out BUT know they
>>    can add
>>    to bad running issues.
>> 
>>    -john
>> 
>> 
>>    On 12/7/16 8:46 AM, Dan N wrote:
>> 
>>        also...it could be a worn throttle body or a faulty throttle
>>        body switch
>>