Just wanted to pick the collective minds of the experts here first before I dig in. Took my 86 V-12 out this AM for about a 6 mile round trip to the store. Started fine, ran fine, accelerated fine then after I came out of the store, it started fine but as soon as I shifted it out of park it started to idle rough, lopey and stumble. It accelerated fine after an initial stumble and some obligatory valve chatter then smoothed out through the gears. At the red light I put it in "N" and it smoothed out, under "load" it got lumpy again.
Initial inspection is all vacuum lines fitted and snug as well as all injectors clicking, all electrical connectors fitted. The car is well maintained and impeccably clean with no real "faults" in 6 years of ownership, sorting.
Any initial thoughts? Likely suspects? My first insticnt is to replace the fuel filter for good measure and some fresh fuel. I run NON-Ethonol fuel in it.

 

Fuel filter replacement is fine on GP. Make sure to empty it into a clean jar. What you see might dictate your next steps.

Ethanol laced gasoline...not a likely culprit. Stale or contaminated fuel, though, would be a different matter, with or without ethanol.

You mentioned adding fresh fuel. How old is the fuel that you already have in the tank?

Do you have visible smoke from the tail pipes? And/or are the spark plugs black? If so, look for an over-fueling problem. Lots of possibilties there.


Cheers
DD

 

Doug, fuel is fresh, I only put $20 at a time in it and only non- ethanol fuel so it's not stale or bad gas. Fuel filter would be just for grins and to rule it out though I really don't think that's it.