I think she has a 2008 2UZ motor. If that matters.
After reading everything, I would question the MAF more than anything else. fuel pump could be the problem but they usually aren't intermittent with days between failures. MAFS on the can be tricky since they are electrical. i would def. find one to swap it for to rule it out. try unplugging the MAF when its acting up and see if the symptoms improve.
I had a 3rd gen a few weeks ago that barely ran and it was the MAF. it would sputter back fire and not rev up. almost didn't make it into the shop.
Well, her Runner had a total freakout on our way home from ice cream. So, we pulled over and I unplugged the MAF and the engine died, as expected. The CEL came on with P113, P102.
What was interesting is that after plugging the MAF back in, the engine acted normal again, all the way home. There were ZERO hints of what just happened two min ago, even though I flogged her.
So there you go gents, another data point for you.
So that's pretty much exactly what I was thinking would happen. usually you can get a vehicle running with no MAF but it takes a little throttle work and a few tries starting before the engine swtiches to some failsafe mapping. and it usually does run poorly.
I think the MAF is the right path if you cant find someone local, I would replace that first before dropping the tank.
I didn't notice it while I drive it yesterday but I'm curious if she is referring to the fan clutch sound.Is it still making the noise you described where it was loud when revving the engine?
Couple of things:
Dropping the tank? My '96 80 series Landcruiser has a top access for the fuel pump and sending unit. Surely this '08 modern 4Runner has the same thing, no?
I'm tempted to swap out her MAF with mine (non VVTI) and see what happens just for S&G!!
S&G!!
This issue reared it's ugly head yesterday eve on the hwy as she was heading home. She unplugged the MAF sensor but that didn't do anything. The usual DTC codes came up and the engine wouldn't start or hold the idle.
So, I went to her and was getting ready to tow her to my house but then the engine started. I drove it to my house as she followed me. The engine didn't like to be pushed under load and it stumbled badly around 1500 rpm or under. So basically the engine didn't like to be pushed under load. This issue can be recreated by power braking as well on the driveway.
Around 10pm last night, I started the engine up and power braked like normal. Lo and behold, she is right as rain![]()
I drove it to work this morning and she is driving her normal self.
So, it looks like a component is getting hot and malfunctioning. As soon as things cool down, life it normal again.
Switching the MAF is a no go as the connectors are indeed different as mentioned previously.
The ambient temps in ABQ was around 100 deg yesterday.
well the first 2 codes were likely set from disconnecting the MAF, then 2 lean codes, a VSC trigger code and bank 2 misfires.
Its interesting that it only is missing on bank 2. but leaning out on both banks.
Do you have access to a heat gun? maybe try hitting various things with a heat gun such as the O2s, MAF , Cam sensors and even the PCM is self. be mindfull not to melt anything
Do your scantools show commanded injector pulse width and good data lists?
I would try to replicate the issue and watch the Short & Long Term Fuel Trims as well as the O2 Sensor responses as the computer tries to adjust. I'd also see as much data as you can pull on the injectors to see what the ECM is commanding out of them along with MAF sensor data.
IF there's a heat related fault in the MAF or Injector coils you should see the MAF start giving odd numbers, or the Injectors having increasingly higher and higher pulse width despite the fuel trims and O2 sensors reading lean and/or showing little to no change as a result.