Low RPM no power and rough running

[lrm]

My 2002 Mountaineer 4.6 liter V8 when it gets moving above 40-45 mph the rpms drop way down to 1500 or so. If I barely push on the gas to speed up slightly and it doesn't downshift to high rpms, it rumbles, bogs, seems like it's going to backfire. I replaced plugs, had a bad coil replaced (coil over plug so no wires), checked for vacuum leaks (great threads on that on here!), and all checked out. It idles fine at a stop.

Is this the dreaded timing chain issue? Loose maybe? It's not all the time though. Only low rpms cruising and step on gas pedal lightly. Get above 1800-2000 and it's smooth, pulls well. I've checked the spark plug gas twice, in case I had them wrong, all are very close to .054.

 

[waskly]

4.6l do not have dreaded timing chain issues.

maybe your feeling a miss fire? scan the car. throttle body gummed up? bad clogged maf?

 

[lrm]

4.6l do not have dreaded timing chain issues.

maybe your feeling a miss fire? scan the car. throttle body gummed up? bad clogged maf?

Timing chain problem in 4.6, that's good to know. I sprayed carb cleaner down the throat of the throttle body, used a toothbrush in there to scrub out as much carbon as I could. MAF got a couple cleanings, sprayed with carb cleaner also.

I drove it tonight about 40 miles. On the way home there were no new engine codes came out which was good. Putting the new coil in seems to have fixed the 302 code I was getting. I noticed when I hit the gas to speed up it didn't take off, as I eased up on the gas I could feel it take off, like a delayed response. I'm now afraid it's tranny problems. Possibly the tranny isn't shifting when it should and bogs the engine down.

 

[D Hook]

Might want to do a search on cleaning the MAF. Seems I read something about not using carb cleaner because it leaves a residue and ruins the MAF and that you should only used cleaner specifically made for cleaning the MAF. Also read the throttle body cleaning can cause problems if done incorrectly.

I'm new to the Explorer so you'll want to verify that info with search.