rlx101

Hey guys im totally bummed out ... so today i went in and cleaned the MAF with CRC spray liquid. While there i changed air filter as well. Put everything back together, went to the gas station, filled up and the car would not start - the idle went down to like ~100rpm. i had to pump the accelerator a few times to start it and have to keep pressing on the gas pedal slightly when stopped for the car to not stall again. If let it sit it, the rpms drop and engine stalls. Prior to cleaning the MAF my idle was fine at 650rpm and i had none of these issues, now idle is at 100rpm or less....

Now on the CRC bottle i noticed following "do not use on vehicles with Karman-Vortex air flow sensor..most Lexus vehicles". Did i ruin the MAF?? I never heard people warning to not clean ES300's air flow sensors with CRC...

Just to make sure i went and disassembled/reassembled everything again to make sure i hooked up everything properly. Vacuum lines are hooked up properly, no cracks. i took a couple vacuum lines off (one by one) while idling and there is suction and engine did not stall... is it supposed to?

Anyway, not sure what to do now... do i go and get new MAF?

Once when it stalled i think i heard some high pitch sound seem to be coming from the left side of the engine around actuator... could i have pulled and done something with one of the the vacuum lines and its leaking now somewhere hence engine is stalling?

please help...

Bumbobee

Oh man that's crazy.

I would try cleaning the sensor again, making sure it dries out properly before installing it back in. I would also clean the throttle body of the car just to make sure all the gunk and junk is out. I would then disconenct the battery and reset the computer. Turn it on and pray.

What kind of air filter is it? If it's a K&N with oil the oil might of gotten onto the sensor.

rlx101

yeah kinda crazy .... considering i never had these problems before.

air filter - is just standard off the shelf replacement filter, so no oil contamination. I did a bit of reading and looks like sometimes MAF connector contacts become lose hence messed up signal from MAF, so i went and checked the wires - they look fine as far as i can see. Just in case I slightly bent the pins in the MAF to potentially improve the connection with the connector, still has a problem starting - have to gas it up a little and idles low.

I removed the MAF again, sprayed it all over, including contacts, will let it dry overnight inside and hook it up in the morning. Pray for me lol

p.s. is there any sure way to rule out the connection problem?

EEngineer

probably ruined the maf sensor . it's definitely not a vacuum leak because with a vacuum leak you will get higher idle, not lower idle.

there is no point cleaning maf sensors usually. MAF sensors from toyota/lexus all have a built in self cleaning procedure, it goes through temperature cycles and readjusts its voltage reading once it's out of range.

rlx101

Eee excellent....

this AM i put the sensor back in after cleaning and night inside and the car was idling at 650 when i started....left it running for some time lets see if rpm's come down.


one potentially important thing - it was getting pretty cold out (5-10'C) when i was cleaning the sensor...not sure if it had any effect and one has to do the procedure inside at room temp.

worldforgo

Just replace the sensor at this point....

Lexmex

I've used that same stuff from CRC on my MAF too many times to count.

Once I've sprayed it, I shake it and let it drip and then blow on it. I don't let it just sit and dry after spraying it.

What EEngineer mentions is correct on the self-cleaning.

The only thing I have found is that with certain air filer oil, that it can coat the MAF to the point that it won't clean.

rlx101

update: ok, this AM it started fine, idled at 650rpm but then rpm's came down to under 100rpm and stalled in 5-10min or so.. The exhaust smells with gas, its definitely running rich now.

i went to autozone, picked up 2 re-manufactured sensors (cardone) they had in stock, just in case if one of them was faulty. One was refurb toyota OEM, another refurbed no-name sensor. Installed them one by one and im still getting low idle/stalling with all of them!

so that tells me that something else is the problem, unless im so lucky that i mamaged to mess up my sensor and 2 sensors from auto zone are crap. If i disconnect the MAF completely the car stalls, so that tells me that at least connection must be ok?

Is disconnecting the battery for a few minutes enough to re-set the ECU or do i have to pull the fuse? Perhaps ECU is still using the old settings somehow?? Do i need to drive around for ECU to re-learn MAF settings?

EEngineer

disconnecting the battery will do the trick.

rlx101

ok tonight ill try to put old air filter back in or remove the filter completely and see if its the filter restricting the air flow somehow, which is unlikely but who knows at this point. I'll also pull the ECU fuse out to make sure its reset for good. Re-manufactured sensors are going back to autozone as i see no improvement with them.. and for 80$/pop they could have at least cleaned them properly..

Any other ideas to try before i give in and drive to my mechanic? lol

now regarding that Karman-Vortex sensor warning on the CRC can. 2002 ES300 has a hot wire type MAF, not Karman-Vortex, so CRC is ok to use.

GoodRevs

Did you initially disconnect the battery? If so the car needs to relearn how to idle, hence your low rpms and stalling.

rlx101

yes, before cleaning the MAF i disconnected the battery for about half hour.

Hayk

iTrader: (1)

I feel bad for you - trying to do something good only ended up making it worse. I hope you get it resolved.

rlx101

lesson learned - if its not broken - do not touch it!

i feel like this is something obvious that im missing.. driving me nuts though. put my original sensor back in and disconnected the battery, does anyone know fuse location for the ECU?

hypervish

I had this happen to me except the opposite. I cleaned the iacv + throttle body. And, I didn't clean the IACV good enough, so I dislodged some of the dirt (or at least that's what I think i did), and I ended up with a high idle of 1200 rpm in drive even when warmed up. I didn't have time to clean it again, so I kept on driving it. After a day or two it went back to normal. It now idles a tad bit lower than I'd like 580-600 rpm, which isn't too low so I'm not worried. I'll clean it out properly sometime next summer.hahah

So, I suggest trying to clean the IACV valve, and throttle body.

The CRC Maf cleaner is safe to use, I've used it numerous times on my RX300.