Low Idle/Rough Idle - Rough Acceleration

[Razor75]

A couple of questions on my new to me 2002 Explorer. It's the 4.6L. 83K.

I have been searching and searching for days on this site and just wanted some opinions before I dig in. I've read this issue could be the fuel filter, the TPS or the IAC. The Check Engine light is not on.

If I am cruising along at any speed 40 mph, 50 mph, 65 mph, not accelerating the RPMs drop to between 1000 or so and 1500, when I accelerate (especially up hills) the acceleration is choppy until I get the RPM's up over 1500 and then it is nice and smooth.

My explorer starts right up with never and issue. The RPM's drop down to around 600 which seemed to low to me, but didn't really grab my attention until I put two and two together with the rest of the issue. I noticed this morning waiting for a red light to turn green with the RPM's around 600 the idle was getting rough and it is choppy like above until I reach over 1500 RPMs.

Thanks for your help!

 

[Razor75]

Today the CEL light came on flashed while merging onto the highway and when going up hills on the backroads. I made an appt. for service on Monday. Hoping someone might be able to tell me what to expect?

 

[Razor75]

The check engine light flashing means that it is misfiring. I read that in other posts while searching, but none in the 2002-2005 forums.

In my case I had 3 coils that needed replacement (I also replaced all the plugs).

 

[eriom]

Same exact thing is happening to me. About a week and a half ago, was driving along freeway, slightly accelerating, notice a bit of a "hesitation" to accelerate (RPMs going up), then blinking CEL. Then it all went back to normal.

Took it to dealership, they checked codes, found NOTHING.

Today was driving home from work, was at a stop light, notice a "rough idle" as you said.

Tonight I was on the freeway again, accerating to about 60, then noticed the struggle to accelerate, then a slight jerk, then the blinking CEL again. Again, all returned back to normal after I got off the freeway.

I guess I'm going back in to have the codes checked again.

 

[Razor75]

My mechanic said it is quite common with the 4.6 to have the same 3 coils go in those same locations around 80k. With your mileage (about the same as mine) it's probably the case.

Runs like a dream now.

 

[eriom]

My mileage is a bit less than yours.... only at 56K. It happened again on the way to work this morning. It's at the dealership now. No word from then on a diagnosis yet.

 

[chris chick]

Chronic problem it seems.....Mine started thorwing the "check engine" code on the way to work this morning.

rough at idle, sllightly sluggish during acceleration, under heavy acceleration light starts flashing till I slow down to 65. I swung by autozone to ahve the code checked, and they couldn't get a reading from mine. It's a 2001 with 118,000 miles, jsut did a tune up in July.

Are coils something that can be replaced at home??

chris