Fuel trim help

[LvR]

Im unable to record, so as it stands, Ltft is -5% and stft is -12% at idle and at 1500 rpm’s ltft is 0 and stft is -18%. Upstream 02 sensor is oscillating normally from .03 volts to .88 I put a new one in, and down stream 02sensor is at 0.16volts constant.

Again - we need good reference data. If the O2 voltage is swinging normally and as expected, there is no way the STFT can be static as you report - it will always follow the O2 - that is the way the closed loop system is designed to operate.

 

[Bry1234]

Is there anyway to see on a scanner which one could be giving a problem for vvt.

 

[Bry1234]

I will check the scanner this morning to see if it has int/timing and exh/timing option.

 

[zray1]

Get yourself a can of carb cleaner and as the engine is idling, spray the cleaner in and around the area of the intake manifold gasket. Any change in idle usually confirms your issue.

A spray bottle of water will do the same thing, ie change the idle speed.

Only advantages to using water spray is that it’s cheaper and non flammable. Those may or may not matter….

Z

 

[Bry1234]

On scanner all I could get was int valve/ timing percentage which -.50 percent and once warmed up was 0. Ignition timing was within spec. Ltft 1 minute after start up was -10 and and stft was -8 once car fully warmed up it was Ltft -5 and stft between -3 and +1 so maybe the o2 sensor was the problem?

 

[fitrucker]

On scanner all I could get was int valve/ timing percentage which -.50 percent and once warmed up was 0. Ignition timing was within spec. Ltft 1 minute after start up was -10 and and stft was -8 once car fully warmed up it was Ltft -5 and stft between -3 and +1 so maybe the o2 sensor was the problem?

That's normal. Just drive some hwy every once in a while.

 

[LvR]

Ltft 1 minute after start up was -10 and and stft was -8 once car fully warmed up it was Ltft -5 and stft between -3 and +1 so maybe the o2 sensor was the problem?

.................again - you cannot have or quote static figures for the STFT.

Ltft -5 and stft between -3 and +1

Nothing wrong with that IMO

 

[Bry1234]

So case closed, bad 02 senor was the problem. Thread closed