Shifting/ Stalling Help Needed

[quepsiphi18]

This may be kind of lengthly, but I want to include the details to get the best insight:

I have a 2002 Explorer (V6) with 141,000 miles on it.
Recently had timing assembly changed.
Performed tune-up myslef (plugs, wires, coil pack, fuel filter) a week ago
Cleaned MAF sensor yesterday.
Previously experienced stalling when shifting from park to R or D but that is gone.
Current Issue: When accelerating slowly and the vehicle reaches 35 mph or so at 2000 RPM, I get stalling or shifting issues (chugging or hard shift) It appears at the 3rd gear shift point. There is no CEL light present at all. When accelerating quickly, I do not notice the problem. Any help will be graciously appreciated as I just spent $2000 on the timing assembly

 

[EXPLORER04]

the problem could be the MAF. when i installed a new performance intake i forgot to plug that sensor back in and i had the same problems. What did you use to clean it?

 

[shadowless127]

I have the hesitation issue into 3rd at the same speeds as you, but like you at higher acceleration not an issue. Mounty is at the dealer right now for that and some other issues, will let you know what they say.

 

[quepsiphi18]

EXPLORER04: I used MAF sensor cleaner from the local Autozone store. Had the symptom before the MAF cleaning though. Got it at a local tranny shop this afternoon. Hope to hear there is an inexpensive fix for it....