1992 Ford Ranger Rough Idle during start up- VIDEO

[rangerman2020]

Hello, so I have a 1992 Ford Ranger with 60k miles on it. Just replaced transmission lines-fluid-gasket/engine coolant lines-fluid/Spark plugs-wires. It's been idling rough after like 10 seconds of being cranked over. I think a couple culprits I am going to take a look at first. One being my father who previously owned the truck, did not use a air filter for the 4 years he owned it, meaning the throttle body could be dirty. Also, the gas is over a year old though. I am thinking of dropping the tank (since I am about to remove the bed) and draining it to see if that's the problem. Any ideas or recommendations? Thank you. 1992 Ford Ranger Start Up Rough Idle

(Also, I think the valve covers are leaking a little bit, since he drove it without a air filter and I have the time, should I remove the heads and clean them up just incase dirt found it's way in the system while I am doing that? I know how to do it correctly. Thank you."

 

[rangerman2020]

The exhaust has obviously been neglected as well (I have a replacement muffler)

 

[RonD]

Its the gas in the tank, gas lasts 4 to 5 months, at 6 months it will cause misfires, at 12 months its Varnish

Siphon out as much as you can, with hose
Look in engine bay for the OBD1 connector, usually near fuse box, may have Cap on with letters "EEC"
Then look here: https://www.therangerstation.com/tech_library/OBD_I.shtml

2nd drawing is the OBD1 connector with Fuel Pump slot labelled
Remove fuel filter, to replace it, but while its off................
Put a jumper wire in Fuel Pump slot on OBD1 connector and other end of jumper wire on Battery Negative, or any Ground
Have a container down on the ground under fuel line
Turn on the key/engine off
Fuel pump will pump out remaining fuel

Add 5 gal of regular gas that has at least 5%-10% ethanol
Cycle key on again until gas flows out, key off
Install filter

Turn on key one last time and count to 10 slowly
Turn off key and remove jumper wire

Try to start engine, should only take a second or two for fuel system to clear remaining bad gas and air

Run a can of Seafoam or similar injector cleaner in the next 2 tanks of gas
Injectors may be too dirty to clean but cross that bridge after the 2 tanks of gas unless you have a steady misfire

 

[rangerman2020]

Its the gas in the tank, gas lasts 4 to 5 months, at 6 months it will cause misfires, at 12 months its Varnish

Siphon out as much as you can, with hose
Look in engine bay for the OBD1 connector, usually near fuse box, may have Cap on with letters "EEC"
Then look here: https://www.therangerstation.com/tech_library/OBD_I.shtml

2nd drawing is the OBD1 connector with Fuel Pump slot labelled
Remove fuel filter, to replace it, but while its off................
Put a jumper wire in Fuel Pump slot on OBD1 connector and other end of jumper wire on Battery Negative, or any Ground
Have a container down on the ground under fuel line
Turn on the key/engine off
Fuel pump will pump out remaining fuel

Add 5 gal of regular gas that has at least 5%-10% ethanol
Cycle key on again until gas flows out, key off
Install filter

Turn on key one last time and count to 10 slowly
Turn off key and remove jumper wire

Try to start engine, should only take a second or two for fuel system to clear remaining bad gas and air

Run a can of Seafoam or similar injector cleaner in the next 2 tanks of gas

Ok I am going to do this tomorrow and update if it works or not. I highly doubt that it won't work since the gas is extremely old! Thank you for the fast and detailed reply!!