What could cause fast idle?

Anonymous · August 1, 2011, 19:12

I reckon so as they are the only codes but if you change them then you will get your answer. s:D

s:D

Anonymous · August 1, 2011, 19:18

Any pointers for where to get em? The thread about generic sensors confused me a bit. Cheap ones will do.

Anonymous · August 1, 2011, 19:22

The link I posted is pretty comprehensive with links to where to get them or you can try Ebay or pay around £180 each from Toyota.

Mike_V · August 1, 2011, 19:23

w www.sparkplugs.co.uk w
I believe it's the Denso DOX 204's that you need.

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Anonymous · August 1, 2011, 19:24

There are some on eBay for the rav 4 an celica. Any 4 plug ones do?

Anonymous · August 1, 2011, 19:55

Quote from: "Mike_V"sparkplugs.co.uk

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+1 same as the toyota proper one the denso

also the cheap ones can also cause lots of probs

Mike_V · August 1, 2011, 20:00

Quote from: "Mike_V"http://www.sparkplugs.co.uk
I believe it's the Denso DOX 204's that you need

£57.60 each, now that's a bargain!!!

Anonymous · August 1, 2011, 20:03

Quote from: "Mike_V"
Quote from: "Mike_V"http://www.sparkplugs.co.uk
I believe it's the Denso DOX 204's that you need

£57.60 each, now that's a bargain!!!

Denso and plug and play,I would definitely go with these.

Anonymous · August 1, 2011, 20:07

There are two listed on there, a front and rear. Are both the ones I need the same?

Mike_V · August 1, 2011, 20:15

Ron. You need 2x DOX-0204 O2 sensors as they are both the same, that will do you nicely.

Anonymous · August 1, 2011, 20:26

I have a sensor socket you could borrow when you change them.

Anonymous · August 1, 2011, 20:51

All ordered. £120 Including special delivery. If they don't fix it I'll be annoyed. I'm hoping that two knackered sensors are confusing the ecu and it has no idea how much fuel to give the car, hence the problems.

I'll update on weds s:)

s:)

Anonymous · August 1, 2011, 20:59

not sure so much with the import but the o2 sensor on my uk version went didnt cause it to idle high. sorry to burst a bubble and all.

Anonymous · August 1, 2011, 21:03

Well it's a start, I have two faults and they should fix em. After that, I'll sell it if it doesn't cure it.

Anonymous · August 1, 2011, 21:25

Another member sums this up quite nicely.

Quote from: "cclarke99"Personally, I'd replace the sensor with a proper item. After all, it's only the cost of two tanks of petrol The heater doesn't only work at start up, but whenever the engine conditions cannot maintain the sensor temperature just by the heat of the exhaust gasses, e.g at idle or light loads. If it's not at the proper temperature then the mixture will be wrong, causing poor idling and possibly damaging the cat. Alternatively you might miss a much more important fault, like a misfire which could, over time, break up the cat, costing a lot more than the original sensor to replace. Toyota certainly would not have added the heater if they thought they could get away without it; and the control system ftted to the 1zz is well set up and deserves to be treated with respect.

Anonymous · August 1, 2011, 22:00

Exactly. I'll get the sensors in on Wednesday, see what that does. I'd imagine that both of them being faulty would cause fuelling issues quite easily. At least they'll be done, and there are no more faults.

Anonymous · August 2, 2011, 09:16

Quote from: "rbuckingham"not sure so much with the import but the o2 sensor on my uk version went didnt cause it to idle high. sorry to burst a bubble and all.

point 5 of this link explains a thing or two s:)

s:)

m http://www.lambdapower.co.uk/diagnosis/ ... dex.asp#q5 m

Anonymous · August 2, 2011, 14:54

i see where your going just pointing out from my experiance it didnt do that. hopefully and i really do hope that this is the prob of the idle. either way as said before its best to clear all faults that bring on the cel light to eliminate problems so either way its a step in the right direction

Anonymous · August 3, 2011, 16:28

Right the sensors are swapped. The light went out. Still running quick, rich and misfiring.

The fast tick over was due to the throttle cable being too tight. Because the car won't idle.

Poked at the throttle position sensor, revs changed and the light came back on. With a code for the sensor.

So, tps is knackered. New one going on in a bit.

No other codes, no misfire detected. New plugs, clean maf. What next?! Can the tps cause a misfire??

muffdan · August 3, 2011, 16:35

make sure you reset the ecu by disconnecting the battery for 20 minutes. That'll zap the long term fuel trips which are certain to be a mess if sensors have been reading bad data.

muffdan · August 3, 2011, 16:36

If poking the sensor had such an effect, it could be the loom or a bad connection rather than the actual sensor. Easy enough to check if you have a multimeter though.

Anonymous · August 3, 2011, 20:27

So the sensor was the wrong one. Great. Correct one ordered from camskill and should go on when it comes.

Now I have a dodgy fast idle, hardly surprising. And a constant misfire.

One error code, 41. Again, hardly a surprise.

Today I've binned the silly exhaust. Just unbolted it at the join on the drivers side so the pipe points down. No difference at all.

Also binned the pre cats s:)

s:)

Plugs are new, maf is clean, o2 sensors replaced, ecu reset.

No error codes bar the tps. All wiring in tact. Where now? Can the tps being faulty cause a mis fire?

Anonymous · August 3, 2011, 20:41

maybe injector ie leaking so puting more fuel in than should. is the misfire on one particular cylinder

mrzwei · August 3, 2011, 21:13

This post is a bit late really but if you want to eliminate the thermostat then take it out of the engine when cold, put it in a bowl, pour boiling water over it and it shoud open. When it cools, it should close.

My money is on a sensor but I'm not sure which ones are on the 2. Crankshaft position? Camshaft position? Idle? Maf? I've got an O2 malfunction code which is probably causing a fuel mixture code but the car runs fine, no problems with idle but it did have before the cam sensor was changed, but I think the fuel consumption is too high so maybe you've diagnosed it correctly.

I think that if I change the faulty O2 sensor it will solve the perceived fuel consumption issue.

muffdan · August 3, 2011, 21:15

Ok, just read through all of this! Definitely sounds like your thermostat is stuck open. That's a shame as it's a pain in the rear to change. That'll explain the running rich, poor fuel economy, low gauge reading and the high idle.

The misfire is a tougher one to call. Incorrect fueling because of the incorrect temperature reading could cause it. You know you probably need a new thermostat though, in my humble opinion it makes sense to concentrate on getting that sorted and ignore the miss fire for now.