Truck starts great when cold, barely starts when warm

[Strelok]

Picked up a 1990 STX 2.9 a while back, it's in great shape. Needed valve cover gaskets and AC recharge, did that and all's good.

The last week or so it's been having trouble starting while warm. Fires right up first crank when cold. Even if it's only been running for 1-2 minutes it's hard to start.

Sometimes it sounds like it doesn't have enough juice to turn over, but then the starter slowly spins up and it cranks for 3-5 seconds and eventually comes to life. It hasn't failed to start yet, no other electrical issues while running.

It sounds like a dying starter motor to be but it would be equally hard to start while cold so IDK what to think. It's got a stupid K&N filter on the intake which drips oil while running which could be relevant I guess. Any ideas?

 

[rusty ol ranger]

Hook up a timing light, pull SPOUT connector, verify its at 10* BTDC.

Thats classic symptoms of to much advance

 

[Dirtman]

It's got a stupid K&N filter on the intake which drips oil while running which could be relevant I guess. Any ideas?

So take the air filter off and clean it. do you not have soap and water? Your maf sensor is undoubtedly screwed up and needs at minimum a cleaning too if your air filter has so much oil in it that its dripping.

The air filter is probably not related to the starting issue though, that sounds like a dying battery or bad starter.