Build US Spec. February 1990 Poverty 80 2uz/h151f swap

[RivMan]

Here’s a screenshot from my 06 4Runner 2UZ.

My MAF reading at idle is significantly higher than yours. That’s why the fuel trims are where they are.

-Rob

 

[thabruiser]

Here’s a screenshot from my 06 4Runner 2UZ.

My MAF reading at idle is significantly higher than yours. That’s why the fuel trims are where they are.

Thanks for chiming in with your vehicle! I can't see from your screenshot, but are your readings in g/sec or lb/min?

 

[thabruiser]

For reference on a 2005 GX470 (which is what this ECM is out of based on the Techstream screenshot the OP provided)

 

[Tank5]

@thabruiser could you do me a favor and measure the inside diameter of the tube section the MAF sits in on your oem air box.

I would like to compare that to the aftermarket intake I have.

 

[Broski]

@thabruiser could you do me a favor and measure the inside diameter of the tube section the MAF sits in on your oem air box.

I would like to compare that to the aftermarket intake I have.

I have a 2006 tundra, if there anything a technologically challenged idiot, can do to help. Let me know.

 

[Tank5]

I have a 2006 tundra, if there anything a technologically challenged idiot, can do to help. Let me know.

Thanks for the offer. If you could measure the same thing on your tundra it would help see if it is consistent across other 2uz VVTI models. The measurement I am looking for is the inside diameter of the tube where the MAF is inserted.

 

[Broski]

Thanks for the offer. If you could measure the same thing on your tundra it would help see if it is consistent across other 2uz VVTI models. The measurement I am looking for is the inside diameter of the tube where the MAF is inserted.

I can get it for you in the morning

 

[Broski]

Here you go, Denis

And at the air box

 

[Tank5]

Thanks for taking and posting up those measurements. It is hard to which part of the intake you measured in the second picture. Can you confirm?
In the diagram below the part I need measured is the ID of the tube labeled 17705. The MAF fits directly into this tube. I believe it is built into the hood of the oem air box.

Thank you again

 

[Broski]

No worries, I don't mind helping.
The second picture is the tube that fits onto the hat of the air cleaner.
Here

I don't see a diagram,
If I'm understanding you correctly you need the ID of the tube on the Hat ? if so I can get that in the morning

 

[Tank5]

I got distracted. My daily 03 Tacoma threw a P0303 code. I have spent most of my recent garage time trouble shooting it only to find that my #3 three cylinder only has 5psi compression. No good. The other cylinders are at 130 and 140 which is the bottom of the acceptable range for that motor. The engine was rebuilt in CA about 80k ago, so this is pretty disappointing. I am trying to figure out what I will do with it now.

With the daily down I really need the 80 to run, so I got back on the the 80. I have gone through a number of throttle relearn processes multiple times with varied success. I have been able to drive the 80 on short 10 minute trips without tripping the P0171 and P0174 codes. However it still performs poorly. The throttle is still lacking. I have my 2uz swapped 45 and my 2001 tundra with a 2uz as a comparison and the 80 is underperforming.

I did try @thabruiser relearn process last and took the 80 for a 20 minute drive. If felt a little better and still no codes but it still feels underpowered.

Someone suggested looking at the function of the throttle plate on another 2uz to compare to what I am seeing on the 80. I recorded the throttle plate on the 45 which is a non VVTI 2uz. The throttle plate opens up all the way with the pedal pressed. In comparison the throttle plate on the 80 only opens half way. My test is just turning the ignition on without starting the car and then pressing the pedal to the floor and letting it up slowly three times each test. On some tests of the 2uz VVTI, the throttle plate opened up all the way on the first press but only half way on the following two pedal presses. I am not sure why it is not consistent.

I also bought a new oem Toyota throttle position sensor. I installed it two separate times but it is no good it would through three different codes and would not provide any throttle response. I don’t expect Partsouq will take it back. Bummer.

While I was test driving it for the 20 minute ride I had today the fuel light came on and I realized I need to get more gas but need to get premium for it. The gas in it is unleaded. Could this unleaded gas be contributing to the poor performance? I am under the impressions that the VVTI engines are supposed to get premium.

I am going to attempt to take it to town tomorrow to fill it up with premium and see if I get any codes on the longer drive.

 

[Tank5]

Hey Rich,

That is a very clean engine! Looks like I forgot to add the picture. I updated the original post to include the picture but test as you stated in your reply I am looking for the id measurement of the tub coming off the hat. Thanks again for the help!

Curious what fuel do you run in your Tundra?

 

[Broski]

Hey Rich,

That is a very clean engine! Looks like I forgot to add the picture. I updated the original post to include the picture but test as you stated in your reply I am looking for the id measurement of the tub coming off the hat. Thanks again for the help!

Curious what fuel do you run in your Tundra?

Thank you, The truck is a very clean Low mile example of a 2006 first Gen Tundra 4X4 access cab
I run 87 octane regular.
From the owner's manual

And this from the air cleaner hat.

 

[Tank5]

Thank you, The truck is a very clean Low mile example of a 2006 first Gen Tundra 4X4 access cab
I run 87 octane regular.
From the owner's manual
View attachment 3903869
And this from the air cleaner hat.
View attachment 3903870

Thanks so much this measurement might be the reason I am having my issue. Your MAF sits in a tube that measures 69.2mm ID. The tube my MAF sits in is 85.15 mm ID, so just over 16mm difference. So over half an inch. I am going to try to find a MAF adapter as close 69/70mm as I can and see what happens.


I drove the 80 to town today to fill it up. It threw the codes for P0171 and 0174 twice, I cleared them and kept going. It felt under powered the whole time but otherwise it made the drip without any other issues.

Filled up both tank with premium fuel, ouch, and was able to confirm the gauge is able to read both tanks through the switch. That is pretty cool at least. I really like driving the 80, can’t wait to see how it drives after I get this last issue sorted out.

 

[thabruiser]

Hope you get it figured out. Altered intakes can be a fickle thing on a Toyota. Some setups never give an issue. Some (seemingly identical) just have problems. You are welcome to PM me if you'd like to chat on the phone about your setup. I'd be glad to help.

 

[Tank5]

Hope you get it figured out. Altered intakes can be a fickle thing on a Toyota. Some setups never give an issue. Some (seemingly identical) just have problems. You are welcome to PM me if you'd like to chat on the phone about your setup. I'd be glad to help.

Thanks for the offer. I will send you a pm to follow up. Given the issue I am having seems to be circling air and fuel as an issue. The difference in the MAF tube is suspect as it seems reasonable the MAF may not be able to get an accurate air flow measurement if the volumn of the tube has changed.

I ordered a 70 mm adapter that should arrive this week.

 

[Tank5]

The MAF adapter showed up today. After I getting all hooked up to test it out I took it for a drive. No change. I’m still having the same issues.

Test setup.

I feel like I have circled the fuel, air systems, and vacuum leak possibilities. I feel like tearing it all apart and going through it all again to try and figure out what I am missing may be my n the near future.

Edit: After ready back through some of the tech advice I am goin to search for vacuum leaks again.

 

[Tank5]

I went through and individually tested each vacuum line attached to the planum. I either plugged or clamped each line one at a time while watching the tech stream live data and did not see any changes in the fuel trims for any of the vacuum lines.

I pulled the throttle body off and checked the gasket behind it. The gasket Oring was in good condition and pliable. I did not have a replacement, so I cleaned, applied a light coat of Oring lubricant and reinstalled it. No change in the fuel trims.

I tried spraying spraying brake cleaner at all locations that could produce a vacuum leaks while monitoring the live data fuel trims. No spray test altered the fuel trim live data.

Snap shot of the fuel trim I was seeing today.

Not giving up yet, I ordered a smoke machine to test for vacuum leaks. I will post the results of the smoke test after the machine arrives.

 

[RivMan]

Can you post a log showing your fuel trims while driving?

A vacuum leak has the biggest effect on trims at idle, and the effect will lessen under load.

Thanks
-Rob

 

[RivMan]

Also, if you haven’t read this thread, there’s a ton of good info there for troubleshooting a similar issue. I’m only on page 1, so I don’t know if he solved his issue.

2UZ-FE High Long Term Fuel Trims

forum.ih8mud.com

Here’s another thing to check, from that thread:
“FWIW the MAF wiring is a possibility. My 1UZ does the same as yours but on the opposite side of the graph. Runs double digits in the negative trims until I floor it. At WOT it drops to about -5%. Whenever I monkey with the MAF plug the short term trim will immediately start to balance out the long term but after a few hours a driving it all settles rich again.”

-Rob