i recently bought a 2001 dodge durango 4x4 with the 4.7 v-8. i has 141,xxx on it and ran great the past 3xxx miles. i was driving home last night ( about 70 mph for 30 miles) and all it started missing like crazy with absolutly no warning. the check engine light popped on and i had to 2 foot it to make it home. i checked the codes and it had multi cylinder mis fire. #1, #3, and #6. i first replaced all the plugs ( the old ones have been in for a while and were burnt down to about .080. i replace with platnuim plugs and it didn`t help. so i checked the codes again and it had the same codes. i replaced all 3 coils ( oh yeah, it doesn`t have a distributor). it seemed to do a small amount better but not much at all. i still have to 2 foot it at all stop signs. i also replaced the battery cable ends to make sure it had good ground.

when i take off at stop signs it stalls for a sec or two and then takes off pretty hard ( concidering i have about half throttle) it still misses but it seems to mellow out alittle, not totally.

if anyone has any advice i would really apriciate it. you can reach me at jimmyarnold48@yahoo.com or on here, thanks

 

Repost in the first generation Durango section as this is the general forum. I would clean the throttle body and see if it clears up,
FF

 

This sounds like a MAF or O2 sensor issue. At 141K, both are nearing the end of their life expectancy. Are the MAF and O2 sensors original? MAF issues typically will not generate a CEL. Start by getting a can of MAF cleaner, pull the MAF and give it a spray. If you can reach the filament with a Q-tip for a gentle rub-down it will help. This is a bandaid fix, and you should probably order a new one.

 

ive replaced the plugs again, put the 3 new coils on it and replaced the intake/plentum gaskets. still runs really bad. runs really rich

 

The guys in the first generation Durango section can help you,
FF

 

Jhorn, before you spend any more money on things that won't help, look into the MAF-Mass Airflow Sensor and O2 sensors. Both play vital roles in air:fuel ratio. I would bet on the MAF in this case, it typically won't generate a CEL, but will result in random misfires and poor mileage.

 

it doesn`t have a MAF-mass air flow

 

So they call it a MAP (Manifold Absolute Pressure) tomato, tomato. It serves the same purpose, and causes the same problems.

 

thanks for all the advice, i figured out what my problem is. on the #3 cylinder i checked compression and it had none. i pulled the valve cover off and found the exhaust rocker off and the spring compressed about 1/8tth lower than the rest. so basiclly the rocker jumped off and bent the valve.


again, thanks

 

Wow, that's a little more serious than a stupid sensor! Good luck with the fix.