Tacoma problems

Hey all I'm having some issues that have been going on for a little while and need some opinions. Before anyone says use the search button, I have and found some information but nothing that fully helped since my problems don't fit exactly. I am having an issue with my 2001 toyota tacoma v6 with 205000 miles, manual transmission, 4wd and need some help. To start with my truck throws the error code p0141, and my local mechanic says not to worry about it because it shouldn't cause any problems. Is this true? It also has a few other quirks although they come and go and no one can figure out why. It has a slight power loss and decrease in gas milage which I was told is due to age but I don't buy that. Just like people don't die from old age, something caused it. It occasionally has a low rough idle of about 500 rpms in neutral with no breaks applied. Usually it idles between 1-1.2k rpms. It will also occasionally, when I apply the breaks, idle down very low, then the rpms shoot up to over 1500 and repeat this cycle over and over. I've read that this problem could be do to a leak in the break booster vacuum. I don't think these issues are related because they don't happen at the same time. One odd thing that has happened was i was going through a car wash and my truck started idleing weird and died and wouldnt start for a couple of minutes. I feel it is important to mention I've cleaned the throttle body and replaced the air filter. I've had two different mechanics look at it and could not find any problem. What could be the issue? MAF that's needs cleaned or something wrong with the IAC? Spark plugs and distributer where replaced about 2 years ago.

 

On my phone and your post is hard to read but your normal (warm temp) idle should be around 700 rpms.

The fact it's idling high then dipping low might be a sign of a bad throttle position sensor.

It could also be a dirty intake system.

Have you cleaned the MAF, throttle body and idle air control valve? When's the last time you changed the spark plugs and wires?

 

Spark plugs were replaced with denso plugs, new wires and new distributer installed at the same time about 2 years ago after they went bad. Throttle body was cleaned by a mechanic less than a year ago. Hopefully he did the IAC at the same time because Id hate to go back and do it again. I bought the CRC MAF cleaner to do that today but was held up and ran out of light so I'm doing that tomorrow. Could that cause all these issues? Also would my error code P0141 cause any problems? I know it is only monitoring after the catalytic converter but could that have an effect on the computer?

 

Update: I cleaned the MAF sensor today and it made a big difference. Warm idle is about 750 rpms now and very smooth. Although the engine has a very slight "bump" occasionally although it's done that for a long time now just noticeable again now that the idle is smooth again. The truck seems more responsive, but that may just be me being optimistic. I'll update later on the looping rpms while breaking since it usually only occurs first thing in the morning. I put a fresh tank of gas in this afternoon. I want to see if I get an increase from the 15-16 mpg I was getting.

 

This thread hurts my eyes.

 

run a bottle of your favorite injector cleaner and do the Seafoam treatment

https://www.youtube.com/watch?v=58sj81ejhM0

or this (easier than sipping from PCV hose)

https://www.youtube.com/watch?v=O5N_Z1W6mho

 

the fluctuation in RPMs sounds like a vacuum leak to me. I'd get a can of brake cleaner or something, spritz it around the engine bay and see if the idle changes when you're spraying in a certain area. If it does, try to locate the leak from the area in question.

 

Are you sure you have a distributor on that?

 

I thought that too, my 2001 doesn't

 

my '00 3.4L had issue with it's IAC
rpm at idle tended to increase/decrease at will
and near abouts the rpm's you state
eventually it just wouldn't fire at all.

was carbon build up on the IAC vane...
The IAC is an expensive part to replace new
tho' it's possible to be removed, cleaned up, reinstalled
and work again after a thorough cleaning.

Seafoam treatment will not clean the IAC

I had success cleaning an IAC before.
But the IAC must be removed from the intake to be cleaned.
And I needed use a hardwood thin dowel
along with brake cleaner to soften the carbon deposits
to assist in scraping off the carbon build up off the vane.

Don't leave any chemical residual in it
after cleaning or that could damage some sensors.

A dirty IAC is common with high mileage 3.4l vehicles