From one thing to the next...

Hey guys, I made a post a few months back regarding my Tacoma's poor performance. With a lot of people's help on this forum I narrowed down the big issue to the fuel pump. So, after like 3 months I finally have replaced the pump. Made a huge difference without a doubt. I can actually take off from a stop quickly without horrible hesitation, but I've ran into another issue regarding performance once again and I'm hoping yall can help me out.

The issue is not nearly as bad as before but there's still just a little situation that involves something to do with air and fuel. I'm still getting some hesitation at a cruising speed when i put my foot down. Down shifts like it should and revs up but there does not seem to be any strength behind the revs. I'll be at like 3k rpm and will slowly climb with speed and revolutions like a dang snail. Overall the truck runs so much better, it's just doing kinda what it did before just not nearly as severe. I'm getting no check engine light yet or at least have not had one for a while. During the warmer months it would throw a lean code and on a cold night it threw a rich code all before i changed the fuel pump. I assumed it had all to do with the pump because a guy told me it can throw lean codes. What's interesting is that it threw an rich code one time on that cold night. I hooked my not so sophisticated scan tool to the truck after the pump change. (which was today) Had no codes. I checked data and fuel trims seem normal... I guess. They are a lot different than they use to be. One thing that stood out was O2 sensor voltage. Bank 1 was running like 0.3v and bank 2 was like 3.5v. I believe 3.5v if too high. Here's a list of everything i have checked or replaced so far in the last year:

MAF Sensor
Spark plugs
Cleaned throttle body
Checked all air hoses very closely
Did a vacuum test for leaks and catalytic restrictions
Replaced fuel pump
Truck has 335k miles

Any help is appreciated. Merry Chistmas

 

Maybe disconnect the battery, wait ten minutes and reconnect. Should reset the brain and after awhile, will relearn how to drive with a new fuel pump. And maybe not, but the time and costs involved should be manageable.

 

Miles on vehicle?

Last time transmission was serviced?

Your description is similar to a slipping trans

 

Just thinking the same but who knows?! Won't hurt to check it anyway.

 

Sounds like the VVTi solenoid or the PCV valve. The PCV valve is very cheap $10 part, but the VVTi solenoid is $300. Either part can cause similar symptoms as you describe especially without a CEL or throwing codes.

 

335k miles. I got the transmission serviced on the 280k or 290k mark. I had a feeling of that too but the situation seems to be sporadic and I've really only driven the truck 20 miles after I replaced the pump but I'll pay attention to that as well.

 

I seriously forgot about the PCV. I'll look into that for sure. Same with solenoids.

 

With miles that high has anyone thought about checking the gas pedal? these trucks are drive by wire.