gonetowin

Hi All,

I'm new here but have spent a fair amount of time searching this forum for ideas on a problem I am having with my 06 Tacoma TRD. It has the v6 with automatic transmission and has 185k on it. I found a very similar story as mine that described the problem pretty closely but since it was a different year/model I thought it was worth a shot to post something on here. Thanks much in advance for all the advice as it seems there are a lot of knowledgeable people on here.

Here is the problem I am having...While I am going up a mild grade or even steeper grade my engine has the slightest cyclic bog or hesitation in between 2500 and 3000 rpm. It seems to last about 1 second and comes on and off about every 5-10 seconds. It is by no means a large drop in power as the passenger likely can't feel it other than the audible tone that changes slightly in the sound of the exhaust. Its almost like I am feathering the throttle slightly but I am not. I don't think it is a miss as that would be way more drastic in terms of power drop. I'd estimate it dropping the rpm about 100 rpm when it bogs. It appears to happen only when the pedal is at a constant position and it goes thru that rpm range and I can get it to go away when I stomp on the pedal and get it to down shift or let off a bit. No problems stomping on it and accelerating or at high engine rpms etc. I started noticing it this year while towing my trailer, which weighs about 3500 lbs loaded and cannot really get it to reproduce the same problem without the towing load unless you are tuned into the problem to begin with. Without the trailer I am able to feel it and hear it but since the truck isn't loaded it might only do it once when accelerating. When I hold the throttle at 2700 rpms or so without the trailer, it won't do it because its not loaded enough.

Here is the kicker...no check engine light or anything so I don't know if there will be any codes stored etc. Its never thrown a CEL actually.. I was thinking about taking it to the dealer and letting them figure it out but I am thinking that it will be a waste of time at this point since I'm pretty sure they won't be able to reproduce it unless I leave the trailer attached and I drive them up a grade.

I cleaned the MAF sensor and throttle body. Both were quite dirty but didn't fix it. After I cleaned them, I had to reset the ecu by taking the power off for 10 mins because when I started it back up it was idling high. reseting it promptly fixed that hiccup but the bog still remains a mystery.

I have thought about checking the fuel pressure because I have read that the fuel pumps can sometimes go at this age but am not clear where I get the special fitting to tie into the fuel system rail?

Any thoughts or ideas would be great.