Hello,
Ok everyone I have been searching the web for 2 weeks now and going thru every bit a electronics in this car. I traded the car for 1990 ford ranger with a 2.9l. The shop said they had it for a year and coudn't figure out way it had a miss fire. Well i did the normal coil, plugs and wires. Then it wouldn't idle period with the TPS and IAC plugged in at the same time. I ended up replacing the ECM with a junkyard one. I mean to get it to at least idle i had to unplug 1 of the 2. No it idles and goes down the road. I drove it yesterday for 15 miles and it misfired a few times. Later that day I ran the same route and it mis-fired all to hell. I was hoping if i ran the fuel thats been in there a year it would clear the mis-fire. I have put 14 gallons in it and this has been over the last 2 weeks of working on it. Well I stopped at autozone today and had 4 codes 1 random mis-fire, then a mis-fire on 1,2,3. I played the unplug sensor game to see what sensor did what. Everything but the crankshaft sensor either stopped the engine or made it run differently. I grabbed another junkyard sensor and still doing the same mis-firing. It only mis-fires going down the road under load or going up hill. It idles perfectly. Does anyone have a clue. Other than the mis-fire it runs and drives great.

 

Ok I know it's a Hyundai body why isn't anyone responding. Is the car that much POS and do i need to get rid of it.