Lacking power - fuel pump? timing issue?

So I've been MIA for a while on TW - trying to just drive my truck for a while and ignore all the cool things I want to buy for it. Last week I drove about 140 miles and for most of the trip my truck felt like it was lagging. It felt like it was lacking its normal power and didn't want to get up and go. More skinny pedal just made more noise (higher revs) but it wasn't really accelerating like it should. I'm trying to figure out if it's a fuel issue or timing issue. I'm hoping for fuel because I'd rather replace a fuel pump than deal with electrical gremlins, but it hasn't done it since. This also happened once about 6 months ago but it was early in the morning and I thought I was just half asleep. I'm headed to Montana in a couple weeks and don't want to have it die in the middle of nowhere. What say you?

06 AC 4x4, 90k miles, the rest should be in my sig.

 

damn, nothing? Bump. Anyone? Bueller?

 

bad fuel?

 

IS your truck man or auto? When did you do your spark plugs?

 

Now we're talking. Air filter is back to stock as of 3 months or so ago. First time it did it was with the K&N/AEM combo. Both filters are/were relatively clean.

I'm hoping for bad fuel, but am a bit leary because I filled up about halfway through the trip and it didn't change. Next day it was back to normal power.

Plugs changed at 68,500 so I doubt they are the culprit.

Auto trans.

 

I asked about plugs just t ocover it. But one item that is interesting is that RPMS went up when you pressed gas but truck did not follow.
Bad Tranny then? If you had manuall it would sound like slipping clutch, auto tranny does similar thing when has issues.
When and if fluid was replaced in transmission? You are at 90K mark so I would think that's the time to do it. Also are there any leaks on the tranny?

 

It's kind of hard to explain the feeling, but I'm fairly certain it wasn't the trans slipping. I do get a weird shift every now and again, but it's usually the 4th-5th when it's cold or the torque converter locking/unlocking when cruising on the highway at the annoying 45-50 mph range where the trans is confused what gear to be in. I did the drain/refill of the trans pan at 76,500 miles (yes, it's only ~25% of the fluid) and I need to do it again over the next couple of oil changes or get it fully flushed. If it was slipping I would expect it do it it more consistently.

I'm still thinking it's the fuel pump on it's way out...it's the cheapest thing I can think to replace at $155. I still don't really trust the in-tank "filter" screen thing on the stock pump.

http://www.urdusa.com/product_info.php?cPath=79_12&products_id=1260518592

 

I dont know, if fuel pump went bad there are atleast 4 sensors that would complain about. Since you did not post any Cel codes I am assuming you are not getting any.

 

I would start with tune up items. Plugs, air filter, fuel cleaner and maybe even a bottle of (mild) octane booster in case of bad gas. Do all that and I bet it'll feel like a new engine again.
Fuel pumps in japanese vehicles will last longer than the vehicle itself in most cases.
Timing is controlled by the ecu so that's not it. If the engine was off even 1* you'd know it. Oh yeah, and after you perform a tune up, reset the ecu by disconnecting the NEG battery terminal so the ecu can relearn with the new parts.