I have a 05 Lariat and when at WOT coming from a stop or going onto an onramp or something there is a sudden loss in power in the lower midrange that last just a split second then maybe after another 800-1500 RPM it does it again. Like clockwork it happens around the same RPM every time. It feels like I let off the throttle for a split second when it happens. I checked the air filter, cleaned the MAF, ran bg44k, changed the fuel filter, unhooked the battery, and now I am at a loss. I am running 87 now, but it did it with 89 also. It doesn't sound like a miss to me. Could the computer be pulling timing or closing the throttle because of an underlying problem? Would it throw a code if it did? Truck has almost 70k miles and the only noise under the hood I can hear that wasn't there when I got it is the cam phasers (not that I would be able to hear any other problem over the noisy cam phasers)

 

Have you changed the plugs? My 06 with 58k had a simalar problem, whenever there was a load on it it would cut out, did the plugs Monday and half the electrodes were missing. Now she runs like new. If they're original, it may be them that is the culprit

 

I really don't want to change the plugs out on this thing but its looking like its the least expensive possibility at this point... I guess I will give a couple dealerships a call and find out what they will charge.

 

Have you put dry-gas in it??? Maybe you have some moisture in the gas. It would likely happen at various engine speeds, but maybe you only really notice it when at WOT???

Its worth a try before you change the plugs.

 

This morning on my way to work after the motor was about to operating temp. I gunned it and it felt like I had a v6 under the hood and after a second or so it surged quickly then onother second or so after that the power came on like I would expect for the first run of the day on a cold morning. It doesn't seem like an ignition issue at this point as it happend long enough to plainly hear that there was definitely no miss. Felt like it was absolutely pig ritch, or had the timing pulled. I have been getting pretty craptacular mileage lately. Has anyone known these motors to ever be ritch? I'm not too familiar with this VCT stuff, but it seems like it is too much of a difference for the cam timing to be jumping around on me, but maybe I'm wrong. I know the cam phasers are shot becuase they make a TON of noise, but I read somewhere that when they wear out that they still perform thier job adequately.

 

maybe the MAF got damaged when you cleaned it????
If it was reading wrong it could make the engine run rich (right???)