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I have an 85 myself so I know this is possible. Try siphoning about 2 gallons of fuel from the tank. Make sure the siphon is on the dead bottom. I think you have water. Also after you siphon the fuel, take a sample and see if you have water by letting it separate in a glass. Water is on the bottom so a siphon will get it. Also replace the O2 sensor and take it for a long drive. Another part that will make it run terrible is a bad airflow sensor. If you have no water and a good O2, try another Airflow Sensor.
Think of it this way if you had a 1/4 barrel of sewage and you added 3/4 barrel wine to it, what would you have?
This is my first time trying this Just Answer service. Can answer more questions? How does this work? It seem to be idling ok, but when I step on the throttle, it stumbles badly, like it just ran out of gas. Idles fine, but step on it and it wants die. I'm starting to think I have more than one thing I'm dealing with. If I tap the throttle repeatedly, the rpms come up, but if I just step on it, it stumbles and coughs. It feels like once when my MAF went out.
This thing is being such a pain. I had it idling while I was in the house. Went back out and it had died and won't start. It's been doing that. It's been starting once the engine gets a little cool. I''ll try it again in about 15 minutes. This thing used start right up. Now I"m having to crank it a long time and it kind stumbles into a start. How long are on tonight? It will probably be about 15 minutes before it will start for me.
Its hard to say but you got to get it out of the vehicle. Any oil change shop will take it and mix it in with their waste oil. Do it 5 gallons at a time. DOnt run it through any of your other vehicles as it may damage something.