Fix your car!

[Javi802]

Ok, so doing some research, i found this video and it is extremely helpful. Its to help you figure out why your running rich or lean.

Determine what your engine is doing based on the fuel trim, which can help you diagnose where the issue stems.

You'll need to buy a consult program to do so.

https://www.youtube.com/watch?v=5WnM_NsOtd8

https://www.youtube.com/watch?v=cARQ0jZZ4Qc

[cotbu]

I was explaining just that to you. So did you fix your problem?

Sent from my Highly Tuned Note4!!!

[Javi802]

To be honest. No, lol. I was hoping i could go off of the base a/f (aka a/f alpha) to figure out where the problem is, but I wasn't sure the sr20 had a long term fuel trim and a short term fuel trim.

NDS only lists a base a/f. Which I'm unsure whether that is the long term or short term.

[cotbu]

Check for vacuum / boost leaks.
You can use the 02 sensor gauge in nds, it is supposed to swing back and forth, yours stays pegged. Compare the swinging back and forth motion to your wideband it will probably be 15.2 to 14.5 area.

The tools you can use:
Rpm test, Curb side emission test:
hold the throttle at 2500rpm the wideband
should read 14.7 and the nds 02 gauge should be swinging back and forth like crazy
This could indicate a vacuum leak.

Your adjustable fuel pressure regulator:
Use that to lean out the afr. Don't worry about what the fuel gauge says. You are just testing. Make the afr lean to about 15afr log at the same like time.

I think its a vacuum leak or a faulty mafs.

Sent from my Highly Tuned Note4!!!

[Javi802]

Yeah thats whats weird. Is that the o2 swings back and forth when i hold the gas at any rpm.

The afrs also stay within stoich when holding the rpms.


When you say a vacuum leak, you mean before the throttle body right?

Ive noticed that if i cause a leak in a hose that is after the throttle body, while in idle, the afrs go lean and idle goes up.

When ever i had my BOV recirc hose undone and was messing with the soft/hard adjustment, if i made the BOV too loose, it would cause bogging and a rich afr



And yes, I've been lagging on getting that boost leak test done. :naw: :mepoke:

[Javi802]

Do you know if the SR has a long term fuel trim as well as short term?

And whether or not the value that NDS gives, is the long or short term?

[cotbu]

Yes it has ltft and stft, you can watch the short via 02 gauge. I dont know if you can monitor the long term fuel trims with nds, but they can be cleared. Thats what i do, and watch for any big changes, then correct if necessary. Also i use nistune now.

Sent from my Highly Tuned Note4!!!