MAF sensor cleaning spray

[SeanR]

I plan on buying this MAF spray and cleaning off the honeycomb sensor. I took the intake hose off over the weekend and found a moth wedged into the honeycomb which seemed to cause the car to have a rough idle. Picked most of it off and could quickly see an improvement in the idle.

[Guest Kingsley]

My experience with this product has been excellent and it's use should be a great help.

There has been a good bit of previous discussion on the cleaning of the MAF sensor and I will see if I can trace it down.

[2seater]

The actual sensor is in a small passage inside the MAF casting. It is removeable from the upper front of the casting and is held in place with three stainless steel screws (non-magnetic). The screen is only to smooth the air flow and it is removeable. A large snap ring holds it in place but it fits tightly. Usually easier to remove the whole casting (four screws) from the throttle body and push the screen out from the inside, or, once the actual sensor is removed, leave the screen in place and reverse flush it with cleaner or just hot soapy water and rinse well. Once the sensor is removed, there is nothing else that can be damaged by simply washing it with detergent, rinse and dry. If the moth was in front of the passage for the sensor, it may very well act as you mention.

[SeanR]

Finally cleaned the MAF with the MAF cleaning spray today and wow what a difference! For a 44k mile engine, it really helped the idle. In gear, it used to sputter and vibrate more than I thought it should. Tonight, it runs like a brand new car.

[Guest spongebob]

ive heard that k&n filters are terrible on these sensors..because of the oil in the filter..

[charlie1]

If you have a K&N filter on a new Gm car and take it in for warranty of the sensor it will not be covered.

[jerrykiefer]

I picked up a Red/tan 90 coupe from a gentleman in Daytona Beach over the weekend. The car runs excellent but the EO 34 MAF code stays on despite clearing it several times. Does this indicate the MAF sensor needs cleaning

or do we have another problem?

It has the original air intake system and both the ECM and BCM computers have been replaced in the last year.

Thanks for the assistance!

[padgett]

I'd pull the MAF and see if one of the coils (are 2) was broken, how well does it run ?

[Guest Mc_Reatta]

E034 indicates the ECM is not seeing a signal from the MAF.

Do you have a DVM? Need to see why your not getting that signal. Afraid you are beyond a simple cleaning of the MAF, but you may just have a problem with the connector. Have you checked it and the wires?

Edited April 30, 2012 by Mc_Reatta (see edit history)

[jerrykiefer]

The car runs great, idles very smooth, no stumbles and got 25-26mph on a 250 mile run down I-95 at 75 +/- mph yesterday.

I've got a DVM, where I'm I looking and how much voltage should I see?

Thanks!

90 Reatta couple

123k

[Guest Mc_Reatta]

The car runs great, idles very smooth, no stumbles and got 25-26mph on a 250 mile run down I-95 at 75 +/- mph yesterday.

Maybe you shouldn't do anything

I've got a DVM, where I'm I looking and how much voltage should I see?

Thanks!

Check fuse #5 (10 amp ECM fuse)

Disconnect the MAF electrical connector and then turn ignition to the run position.

Measure voltage in the connector between the yellow wire in terminal A and the black/white wire in terminal B.

Should be between 4 and 6 volts. Is it?

Edited April 30, 2012 by Mc_Reatta (see edit history)

[jerrykiefer]

Thanks for the advice, I'll check the voltage tonight.

[jerrykiefer]

Took me an extra day but I checked the voltage on the MAF and had a hair over 5 volts on the plug with the key on. The fuse was good.

Got my new can of CRC MAF cleaner and hosed her down then gave the trottle body a CRS TB cleaner bath.

THe E0 34 continues to keep setting but since the engine runs great I'll let sleeping dogs lie.

Next up I'll follow Padgett's instructions and clean the IPC as the idle will hop up to 800 rpm from time to time.

Thanks for the help

Jerry

1990 Red coupe (problem child) 123k

1990 Black convertible (previously one of Padgett's flock) 120k

[Guest Mc_Reatta]

Sounds like a bad MAF.

Can confirm by checking voltage of the other pink/black wire at pin C against that black wire at pin B. Same conditions, connector disconnected an key in run position.

Should be battery voltage ~ 12.6 volts.

Did you ever do a tap test on the MAF? With engine idling, tap the top of the MAF with the handle of a screwdriver or something similar. Idle should stay steady. If it stumbles, you have a bad MAF.

Also set up diagnostics to display ECM Data value for ED21 "Air Flow" as you drive around.

Believe it will be around 4.8 or so at warm idle and rise as throttle increases and return back towards the idle value as you let off.

E034 sets when the ECM sees dropouts in this signal. Does signal stay steady when the throttle stays steady or does it vacillate?

If it does you have a bad MAF.

[jerrykiefer]

Looks like a bad MAF. Voltage is a bit over 12 volts on the plug with the key on.

Tapped on the top of the MAF and a couple times it stumbled and two times the engine shut off.

On the otherhand, at idle I get a reading of about 6.1-6.3 on ED21 which increases to just over 20 as the throttle increases (driving).

I don't see the signal dropping out but it could happen so fast that I don't see it.

From all indications, the MAF is intermittent.

I'll dig up a replacement.

Thanks for all the help.

One other question, I encountered a bad turn signal on the drivers front this evening,

is it easier to replace from the bottom or the top?

Thanks again.

Jerry

1990 coupe 123k

[NCReatta]

Turn signal is best replaces from the bottom.

Truly the best way to do the job is to remove the whole assembly, and replace all the bulbs. But that may be more than you want to get into right now.