Hello,

I have 1985 Oldsmobile 3.8L. It has been sitting in garage and I took it for a spin. it started fine and ran perfectly. But when I wanted to take again and start it was not starting. when you think it almost starts it isnot starting on starter. But if I press gas pedal more than a half it starts and it runs very rich. Black smoke goes from exhaust and it does not run on idle. after I let it sit for more than a week it started perfectly again and there was no issues and drove it couple days. After that i tried to start and it never been able to run properly.

What I have done already:
Changed spark plugs, changed fuel pressure regulator, changed temperature sensor, changed knock sensor, changed ignition control module, tested ignition coil (gives good spark). OBD1 does not give any error code.
Any other ideas guys because I am out of ideas now. I have replaces all vacuum lines which was not in a good shape and nothing helps. I thought maybe chain got jumped but it cannot be.

As well checked fuel pressure and changed fuel filter. Added as well more gas in gas tank

What does the ECT read?

i do not have obd computer so not bale to check temperature i have read if there are no codes by jumping obd1 terminals

I'd check the ECT sensor circuit. Cold start when you turn the key on the PCM is looking hard at ECT to figure fuel. If the ECT is open it'll read minus 40 and will only start with full throttle. Push the peddle to the floor. Does it start?

Yes it starts even with half pushed throtle and running very rich as black smoke cimes out and not running fine
added video how it runs.
are there any other way without computer how to check that temperature is it proper? As in my oldsmobine there is no temp gauge in dash

The very first thing to check is the ECT.

Do you suggest best way how to check? I do not have OBD1 computer so not able to check it. Maybe somehow ir could be checked with multimeter?

Here ya go.

Wow! Many thanks! Will keep you posted what i will find