After cleaning MAF and TB, does the computer have to adjust itself? - Toyota Nation Forum : Toyota Car and Truck Forums

HotRod53 · 01-07-2012, 12:40 PM

Before cleaning my idle in D while stopped at a light was rough and about 750 RPM, After cleaning it is smooth and 1100 RPM. In P I am at about 1700 which seems high. I'm wondering if it will take a little bit for the computer to adjust and my idle will drop? These numbers were taken after the car was warmed up and driven about 5 miles.

Tech1984 · 01-07-2012, 12:54 PM

When you cleaned the throttle body and moved the throttle plate manually, you disrupted the learned value of the throttle position.
In a day of normal driving or by the time you read this, it will relearn.

HotRod53 · 01-07-2012, 02:08 PM

That's a relief.... I did drive another 2 miles and the idle is down 100 RPM so far.

BlackCamSe · 01-07-2012, 03:16 PM

Next time u clean the Throttel body DO NOT manually open it. Turn your key to on and put somthing heavy on the accelerator. Or have somone else step on it. Doing it manually can screw up the TPS and cause the problem your having. Disconnect the neg battery cable for 10 mins then reconnect it. Start the car. And let it idle in gear so the car can relearn idle.

HotRod53 · 01-07-2012, 03:51 PM

But left alone it will relearn anyway, right?

Tech1984 · 01-07-2012, 08:02 PM

Quote:

Originally Posted by HotRod53

But left alone it will relearn anyway, right?

yes it will, but remember this, if you turn the key on and mash the pedal with something to open the throttle plate, you will set a CEL if the MAF is disconnected. Something to remember.

BlackCamSe · 01-08-2012, 09:30 AM

Quote:

Originally Posted by Tech1984

yes it will, but remember this, if you turn the key on and mash the pedal with something to open the throttle plate, you will set a CEL if the MAF is disconnected. Something to remember.

That's weird because that didn't happen for me when I did mine.

HotRod53 · 01-08-2012, 03:53 PM

I removed my battery cables for 10 minutes as suggested, I cleaned the terminals, added non-corrosive pads, reinstalled, sprayed with sealer, idle is back down were it belongs.

The idle is smoother, probably not as smooth as I think that it should be, but a marked improvement. This is my first 4 banger, it may be normal but not as smooth as my V6 Camry. Definately not lacking on power though.

Instantly the fuel mileage on the readout began to climb back up to the range of the original crappy mileage. I'll probably put plugs in it next, even though iridiums are supposed to last 125K.

HotRod53 · 01-09-2012, 03:36 PM

I took a trip topday that was 130 miles round trip. Previously I took a 250 mile trip and my mileage indicator, although I know it was off by 10%, read 28.1 MPG. Today after 130 miles, it hit 31.0 MPG and I know that it would have kept climbing if I kept driving!

Realizing that it may be off, I'm still thrilled with a 3 MPG increase after cleaning!