Long term fuel trims at +20 - help

2002
3.4
S/C

New MAF (denso)
New fuel filter (Toyota)
New fuel pump (AEM high flow)
No vacuum leaks (Smoke tested)
Reset ECU 3 times

Need to tune FIC, but fuel trims are obviously bad.

Not sure what else to do

HELP!!!

 

What have you done with the fic so far?

 

Nothing

Trying to get my Fuel trims sorted out first

Installed with all zeros

 

Did the lean trims happen before or after replacing all that stuff?

 

Before fuel pump

Not sure on everything else

Started testing after new MAF (denso) and fuel filter

Tested
+20

Changed fuel pump...nothing

Found ALL small vacuum leaks with smoke test and fixed...nothing +20 LTFT

Already reset ECU 3 times....trims back to +20.

 

Weird that fixing the vacuum leaks didn't change it at all.

If unsure whether it was before or after the new MAF sensor then I'd double check that the new sensor is a legit OEM/Denso one and not aftermarket. Aftermarket sensors and Toyotas do not play well together

 

Also beware of fake Chinese OEM /Denso sensors on eBay and Amazon. If the price is too good to be true then its likely fake

 

How does it drive?

 

Got it from the dealership

 

Lean in boost until open loop

 

It's a bitch but you may need to get a fuel gauge set up to it.

I've seen pressure regulators fail on 3.4's. It's not common, but possible.

So is injectors, but not all 6 at once, you are talking both banks LT is +20 right.

 

Ok start there.

Have you setup the Fic maps scale? (Psia & rpm)
Have you calibrated the Rpm and Tps signals?

 

No

I thought my fuel trims should be 0 before I could do that?

 

You have a modified vehicle, Ltft wont be 0.
Setup the fic so you can start making adjustments.

 

This is kinda what I was thinking but others have 0 LTFT with a S/C...weird right?

I was thinking with more air the ECU would have to inject more fuel right?

I’ll get started on programming the FIC

At least my intake pipe is tight as a snare drug now!

 

I am having the same issue 1st gen 3.4 new engine, I think I have it down to with bad cat or o2 sensor

 

My LTFTs and STFTs are around 5 on average.

What are your short term numbers

 

5 ish at most

0 at idle

 

The Fic is going to be stuck in 1 cell. You need to get the x and y axis scaled and calibrate the rpm and Tps signal. Then you can click "guages" and see what area of the map the fic is working from.

 

Those are good numbers at idle!