Fast Idle (1 Viewer)

[2001LC]

The ECT is likely high, due to dirty radiator fins. Can be other issues also.

Radiator fins need cleaning! Alert Alert Alert

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...

forum.ih8mud.com

But if your running lean, like a vacuum leak. This will have engine running hot. It also may be due to vacuum leak.

I can't be of help much with scangauge. But I'd assume you just scroll through available data points. TLFT STFT may be how listed. I use a blue driver. Which logs and I can then look back at moment by moment over as much time as I've logged.

We're just interested if fuel trims showing anything strange. Reads between + or -5 % while throttle steady is normal. Getting over -+15% is get bad. Even -7 STFT (short term fuel trim) is indication of lean fuel mixture. LTFT would then or should then be positive about 7%. As it (LT FT) show the new baseline ECU has set to correct short term (ST).

You need to read tech stream for codes pending. Assuming your "CEL" is working, present should have CEL on, pending would not have CEL on. Easy to check if working, as it should be on with key on, off while engine running. Find a parts store and see if they can read pending codes.

 

[jpd motorsports]

possible vacuum leak? all those hoses going to the air box see if any have any cracks, splits, etc. possibly got a hairline in one. check the maf connector to see if pins are good and straight and reconnect. also might need to let it idle for a while for the computer to re learn idle. mine took about 15-20 mins before it settled down after cleaning both those and battery disconnected for duration. Some freebies to try..

 

[Ddpete1]

Had to leave town shortly after noon to head home so wasn’t able to investigate any further. The CEL does work and isn’t on. Scanguage shows no codes and also has ability to show pending codes, but not picking any up.

Will have to take another look for vacuum leak. Initial check of hoses all looked good and connected.

 

[BnvS]

@Ddpete1 U figure out this problem? and get to a resolution?

 

[nissanh]

@Ddpete1 U figure out this problem? and get to a resolution?

How is the engine coolant temperature sensor, (the two wire sensor, that feeds the temp to ECU)? I had a high RPM even after engine is warm. Replaced the coolant temp sensor and now the RPM dropped to 600 from 1100.

USe an OEM sensor. I infact used one from my 92 corolla! Amazing how the parts are interchangable. I tested the ohms reading of my old sensor (diagrams are freely available online) and found out the old one is out of spec.

 

[Ddpete1]

@Ddpete1 U figure out this problem? and get to a resolution?

I ended up replacing the Throttle Body with a new OEM unit and fixed the problem. First I took it to an independent shop and they couldn’t pin point the issue either. Then bought a used throttle body off a local guy parting out a land cruiser. That unit fixed the fast idle issue but introduced a new issue with the throttle cutting out on acceleration. So just bit the bullet on an new one I ordered online from a Toyota dealer.