I have owned my 1992 daihatsu sportrak for three weeks now and i've had nothing but problems!
When the engine is cold it starts first time everytime and everything is fine and dandy until the engine heats up, once it reaches a certain temperature, it feels like the engine is being starved of petrol(even whith a full tank)when it reaches 3000-3500 revs. This happens in 2nd, 3rd, 4th and even 5th gear but 1st seems ok. I took it to a mechanic friend and he thought it was an electrical fault, so he checked the distributor cap and rotor arm, both of which needed changing, so he did so. However in the time it took him to fit them the engine cooled down again and it drove fine. Until the next day when i took it out again. Since then i've tried a few things of my own...
I changed the air and fuel filters and a load of crap was coming out of the old fuel filter when i changed it so i bought some good quality fuel system cleaner emptied the bottle into an almost empty fuel tank, let it settle for a bit then filled it up with petrol. I drove to a petrol station far enough away from my house so that the engine would be hot enough for the chugging to start and found that on the way home it was still chugging around 3000 rpm BUT it would work through it going up to 4000 before i changed up the gears. It did this all the way home but the following morning and for the rest of the week it ran perfectly, until i had to fill up again when the tank was almost empty again and lo and behold the dreaded chugging returned, but not as bad as before. Before when it happened it would get worse and worse, happening at lower revs until there was just no power there and i'd have to pull over, lift the bonnet and wait for the engine to cool down. now it just chuggs a little. Before and now, it used to only happen when i was going uphill, it didnt have to be steep but as long as its an incline and the engine is warm it will happen. I dont know what else to do so any suggestions are welcome.
Good luck with my mystery!