IS250 Just cleaned my MAF Sensor

[mhforever99]

I try to rewire the wires to the connector per wire diagram, but some how it give me error message P102, P113, and smell funky fuel come from exhaust. I'm not sure if the schematic is good/ my maf sensor. As far I know of pin 3 provide 12 V constant from the Battery. Can someone to confirm if VG/THA which one will provide you the constant voltage for 5 V?

[AntC]

Hey there,

Sorry for reviving an old thread. I bought a MAF Sensor cleaner and I'm planning on cleaning the sensor later today due to some RPM fluctuations when idling and when coming to a stop while in gear.

As far as I'm aware, it is normal to have higher RPM for a few days while the ECU recalibrates to the use of a clean MAF sensor, my question is, if I reset the ECU by removing the couple of fuses, will this automatically recalibrate the sensor?

Also, can I use the MAF cleaner to clean the throttle body as well?

Thanks in advance!

Cheers

[ColinBarber]

4 hours ago, AntC said:

Hey there,

Sorry for reviving an old thread. I bought a MAF Sensor cleaner and I'm planning on cleaning the sensor later today due to some RPM fluctuations when idling and when coming to a stop while in gear.

As far as I'm aware, it is normal to have higher RPM for a few days while the ECU recalibrates to the use of a clean MAF sensor, my question is, if I reset the ECU by removing the couple of fuses, will this automatically recalibrate the sensor?

Also, can I use the MAF cleaner to clean the throttle body as well?

Thanks in advance!

Cheers

You shouldn't experience RPM fluctuations unless the sensor was so bad that the fuel trims have gone way out. You could reset the ECU to speed things along but shouldn't be necessary.

MAF cleaner should be just be normal electrical cleaner (isopropyl alcohol) and so is perfectly fine on the throttle body.

[AntC]

Thank you for the information.

I'll make sure to post results once I'm done!

[AntC]

So I cleaned the MAF sensor and throttle body yesterday using the MAF cleaner and the car did idle at slightly higher RPM initially.

The MAF sensor was not really dirty, but there was some gunk built up on the inside of the throttle body, so I had to take it out entirely.

Overall, i would say there's no noticeable difference in how the car drives, but still, its better to have them clean than waiting for issues to arise.

Just a tip, if you want to clean the inside of the throttle body, make sure to take it out to prevent any gunk going down the intake. Also, be careful with the coolant hoses connected to it, they can break if twisted too much.

[Texas]

And don’t ever be tempted to try and move the flap/valve within the body as it is controlled by a stepper-motor and will/can go out of calibration if forcibly moved.

[AntC]

Well, I actually did move the flap quite a bit so I could clean everything out properly, had no idea that it can go out of calibration. Haven't had any issues so far, hopefully none to come.

On another note, I know most petrol cars benefit from having the step motor cleaned. Is it possible to do this safely on the IS 250?

[ColinBarber]

4 hours ago, AntC said:

the car did idle at slightly higher RPM initially.

probably a result of cleaning the throttle body. Any dirt removed from the butterfly creates a slightly larger opening which results in more air and therefore a higher idle, until the ECU compensates and closes it down.

[Mr Vlad]

It's OK to physically move the butterfly valve because for one the Battery has been disconnected and two the multplug on the housing has been disconnected so the ECU is none the wiser. And yes idle revs are higher after a throttle body clean and there is a system you use to calm it down. I posted it but forget where but its one of my threads about maf and throttle body cleaning.

[AntC]

Thanks for the info. Found the thread and will test it out when I get the chance.

For reference -

 

Cheers

[Texas]

So you cleaned the body off the car? 👍

So if it was not connected or energised when you moved valve then what I pointed out above should not apply.

 

[AntC]

Indeed, I took the entire thing out, after disconnecting the Battery. The coolant hoses were a pain but all went well.

I did test the calibration process but did not notice any difference, I guess the sensor was calibrated from my previous drive.

Thank you all for the info once again. Now I need to sort the VVTi rattle issue, but I'll do some more research first.

[Texas]

Does it only rattle real bad on a cold start up and last for a couple of seconds?

[AntC]

Actually it never rattles on a cold start. The rattle only occurs on a warm engine. For example, drive the car to working temperature, shut it off for 30-60 minutes, chances are, it will rattle for a second on startup.

From what I know so far, this is caused by the cam shaft positioning when the engine is shut off, this results in oil leaking through the VVTi filter.

I did previously replace one filter and cleaned the other, though the rattle did come back.

I plan on having the filters cleaned again next time im at the shop to see if it will go away and for how long.

Any tips on this afe greatly appreciated.

Regards

[Mr Vlad]

Get a bottle of ZX1 and pour it in your engine oil. I've used it in every car I've had in the past 25+ years. 

An example. A neighbour has an oldish S type jag 3.0 V6. Only starts it twice a year. He told me about the top end rattles. I told him about ZX1. He got a bottle. A few days later he knocks on my door saying 'expletives thanks Vlad that stuff is great' no more rattles.

[Texas]

Have you read this TSIB?

 

[AntC]

I did indeed see the TSIB, however, unfortunately, in Europe, it only applies to vehicles that are still within the 70k miles warranty. The only TSIBs applicable to my car are the passenger airbag replacement and fuel pressure sensor. 

Regarding the oil additive, I assume you are referring to this one:

https://www.ebay.co.uk/p/20031190583

However, I'm from Bulgaria and was unable to find any websites selling this brand and model specifically. Generally, the consensus here is that Bardahl and Liqui Moly are the top additive brands, though I've never used any fuel/oil additives so I can't personally comment on their effectiveness.

I also found another thread here regarding the warm start VVTi rattle:

Mentioning that the rattle goes away when the oil is topped up. At the moment, my oil level is somewhere in the middle between min and max, I may try topping it off or changing it entirely.

The video in this thread also shows the exact issue:

 

From what I've gathered up until now, the rattle can cause problems on the IS 350, but not the 250 and is more of a annoyance than anything else. Though it does sound horrible and I would rather have it gone completely.

I'll continue researching and will post any results that I may have.

In the meantime, any information from someone who has dealt with this issue is appreciated!

[Mr Vlad]

Hi Ant. Yes that's the stuff.

[AntC]

So I changed the engine oil a couple of days ago and so far, I have heard the rattle once, though it was significantly less louder than previously.

I'll wait some more time to see how it goes and may end up testing out an oil additive.

Will provide an update once I have more information.

[AntC]

An update as promised, though quite a bit later 😁 

I did try out a lubricating oil additive, however, it did not have any effect.

Just yesterday I changed my oil again at 5k miles and was at the garage during the time. So I had the mechanics top up the oil fully. The engine takes up to 6.3 litres of oil, so I had them put 6.3 litres with 0.7 leftover for top ups. (Note: 6.3 is when changing the oil filter as well.)

After driving for some time and starting the car when warm, so far it doesn't rattle under the same circumstances that would previously almost certainly cause a rattle.

I used Toyota OE fully synthetic 5w30 oil. Last time I used Amsoil 5w30 signature series, and the first time I used Toyota OE 5w30.

It is possible that during previous oil changes the mechanics did not use the full 6.3 litres. I mean, the engine is probably fine with 6 litres.

I will try not to get my hopes up for now (doubt it) and will update if the rattle comes back.

In case it doesn't, the plan is to keep some oil at hand and top it up when necessary, since the car does burn a bit of oil, especially when you floor it.

[AntC]

Another update, no rattle today. I purposefully let the car sit warm for 20-30-40 minutes several times and haven't heard a rattle.

The day of the oil change there was one rattle, and then another very short one that usually doesn't happen. Will keep looking out for it of course but hopefully it's gone for good.

[Mr Vlad]

Good of you to update us Ant 👍

Just goes to show using the correct oil and more so the oil level. 

[AntC]

Indeed. So folks, keep your oil at the recommended level and make sure to change it often.

[NeilS]

Thanks for the advice Ant. How often should the oil be changed? I did an oil & filter change on my car last September, and I drive about 9k miles per year. 

[AntC]

Well, I change mine at 5k miles or 1 year, whichever comes first. Generally, oil manufacturers will say that you can change it at 10-12k miles, but it's always better to change it often. I don't think there's been a recorded case of a mechanical component that has failed due to frequent oil changes 😁