Stalling under load

[maxmileage]

So, at 4000rpm ONLY under load, my engine stumbles and stalls significantly.
No SES light. Out of gear she runs right up to red line without any problems. 2001 3.5 se. 185k miles. I am a bit stumped by the fact it revs perfectly when not under load. Any ideas would be much appreciated. Thanks, Max

[Towncivilian]

Try cleaning your MAF sensor and check for intake air leaks, especially around the flexible elbow of the intake tube. Have you changed the fuel filter within the past two years? Were your spark plugs replaced around 105k miles? It might not hurt to pull one or two to look at their condition, too.

[maxmileage]

Plugs replaced with oem, filter replaced, within the last three months. I have had some coils going in that time and feel like the remaining four that have not been replaced are just not able to keep up after 4k rpm. I have ordered the replacements for those and will do that this weekend. I will also check for vac leaks as well. I will update by sunday with the effects if any of changing out the remaining coils. The remaining coils are original by the way, which is pretty unheard of On the 2001 model i think. I have the pre august production run. So getting that many miles on them I assume they are all pretty beat. We will see. Thanks for the response. Max

[Chuck Tribolet]

A short stumble, or it just goes completely flat?

I have an early '01, 226,000 miles, still have all the original coils.

If it's a short stumble at 4K rpm, I had EXACTLY that symptom at about 120,000 miles, and a
new MAF fixed it.

Chuck

[maxmileage]

Thanks Chuck and TownCiv. I cleaned my MAF and that seemed to help a lot. Still get a smidgen of hesitation at 4k, but I can definitely live with it. Problem now is my Beck-Arnley replacement coils are throwing a p1320 code, I think. As soon as I started the truck up after replacing the coils it threw the code. I am gonna pull them and put the old ones back in tomorrow to see if the code comes back. Anyone know if there have been probs with Beck-Arnley coils here? Got them from Rock auto, so I think I can send them back for exchange or store cred. Just a bit time consuming and dis heartening. Thought I was taking a little preventive maintenance step there by replacing those originals. Took three steps backward instead. Ugh, hope rock auto will take em' back. Thanks again

[maxmileage]

Looks like I can return those coils after all. Now I just have to pull em in the morning and throw the old ones back in. Hey Chuck, where did you get your maf and how much did it run ya, if you don't mind. I would like to be ready if the issue comes back or gets progressively worse in the future. Thanks

[zach7685]

I'v had no luck with aftermarket coils. http://www.courtesyparts.com/mass-air-f ... 80270.html I have the maxima maf above and have had no issues with it. The Pathfinder one is $400+

[Chuck Tribolet]

Looks like I can return those coils after all. Now I just have to pull em in the morning and throw the old ones back in. Hey Chuck, where did you get your maf and how much did it run ya, if you don't mind. I would like to be ready if the issue comes back or gets progressively worse in the future. Thanks

My MAF was a dealer part, installed by the dealer. It was several years ago so I don't remember the price.