Mustang121

Hey there all,

I'm hoping y'all might be able to give me a few ideas to try and fix my 05 v6 problem with rough idle. It showed up after the battery light popped on. The light would come on after the car warmed up and then it had a rough idle as well. I took a look under the hood and checked the alternator out with the multimeter and it was a bit low. So I took it to autozone and their machine said the alternator diodes were not functioning. I swapped out the alternator and that fixed the light but not the rough idle. I decided to do a tune up as she's coming up on 90,000 miles. I've changed the spark plugs, fuel filter, the tensioner, idle pulley, belt,cleaned out the throttle body, swapped the TPS and cleaned out the MAF. I've also run a few bottles of fuel injector cleaner. The rough idle only happens after the car is warm and at idle. I've noticed that if I turn the AC, windows, rear droster on it drops the rpm's a bit and gives a little shutter. Any help would be great. Thanks

JimC

Double check your wiring. On the 4.0 coil pack one side is in numerical order but the other side is not. Very easy to cross them as a result and get a rough running car.

movielover40

The a/c should increase the rpm's.

Derf00

did you check the gap before installing the plugs?

Mustang121

I did one plug at a time, I've had some friends that suggested that too

Mustang121

yep, I gapped all the plugs to the recommended gap

Mustang121

iwhenever I put a load on it just it shudders for a seconds with a little drop in the rpm's but they go back right after.

JimC

I would still double check and trace the wires from the coil pack. One other person was sure that he had it wired correctly and did them one at a time, only to find that he did mix them up somehow. So, worth a check to eliminate one thing.