Tacoma-rough start/low mpg

[voodoojk]

I have a 2012 TRD OR that is basically stock. Lately I noticed a stumbling on cold start and a decrease of MPG. Rght now I get about 14 mpg. Yesterday I had a crank no start 3 times.

Plugs & 4x4 service done at 30k. ( 40 now) just put in new air filter and can of 44k. No CEL are on. No drive ability issue. Kinda stumped. Not bad gas as I have been through many tanks now. Only thing I can think of is fuel filter or pump issue.

Anyone have this issue or something simular?

 

[Elk]

I had an MAF sensor go bad on me a few years ago. It ran rough and threw a code (P0170 if I recall correctly), but no CEL. Use a scan tool and see if a diagnostic is tripped, it should show up. The fouled sensor caused the computer to adjust mixture improperly and I lost mileage and gained hesitation under load.

A new Denso mass airflow unit cost me about $60. There are also threads for how to clean them. The culprit in my case was a new K&N air filter. It came stock with too much oil and fouled the unit, hence back to OEM for me.

 

[SigNewt]

I use MAF cleaner with every oil change.

Spray the cleaner and then use compressed air to dry it.

 

[voodoojk]

The MAF was my next part to address. I brought home a can of cleaner today so will see if that is it.

 

[MTaco]

There was a TSB for that and I think they re-flash the computer. I've had the no start happen on mine a few times but it is so rare I never took it in. It always started after the second or third try. Your mpg's might be from the cold weather and not be related to the no start.

 

[clcoyle]

Throttle Body cleaning

You may also want to perform a Throttle Body Cleaning as shown in the link below. I do it every 30k and I notice improved performance, idling and efficiency.

http://www.tacomaworld.com/forum/technical-chat/94203-how-throttle-body-cleaning-2005-v6.html

 

[p nut]

Did this happen prior to taking it in for the tune up service? Take it back in, I'd say.

 

[voodoojk]

Did this happen prior to taking it in for the tune up service? Take it back in, I'd say.

I did the service at work ( I'm a land rover parts manager) and that was over 10k miles ago. I have also since put in a new battery.