AFM Refresh?

[prossett]

EDIT: As pointed out, it's not the MAF, but the AFM (Air Flow Meter) - my bad, sorry. Pics follow.

Problems with the Mass Air Flow sensor and looks like it's $$$ to replace... anybody successfully cleaned it out or fixed it?

I'm looking for a last-ditch intervention before I buy a replacement.

If it helps, check engine light and limp mode comes on when first driven in the day: goes away if engine is turned off and then re-started. Diagnostics point to air sensor or oxygen sensor. And lately lack of power accelerating, until it reaches 2000 rpm and surges forward. And since a few days ago, sudden loss of power and the accelerator does nothing to raise rpm, and then it works again.

AFAIK, MAF is a flap that catches the speed of the intake of air, and translates that mechanical movement into electric current, which feeds the sensor communicating with the ECU.

Any ideas?

 

[Summiteer]

The MAF is the hard plastic tube with wiring going to it just after the air cleaner housing. It has a tiny bare wire inside it that get's dirty. You can pick up a can of MAF cleaner spray at any auto parts store, then just hose that little wire down until it's clean. Give that a shot and see if it helps. I clean mine about once a year.

 

[gnarlynick2072]

Knowing the dusty crap that can get into every nook and cranny in the middle east, dirty MAF wires could be your culprit.

Make sure it is specifically MAF cleaner not electrical conduction cleaner.

 

[C6H12O6]

I had a quick check engine light, stumbling, surging idle and weirdness when I had a cracked rubber intake hose, too. Might be worth a look, as it is a known source of trouble.

 

[94SRUNNER]

Being that he has a 1993 and 1994, he has a air flow meter on it not the MAF sensor as are found on 95-96' 1FZ's. I dont belelve they are cleaned in the same maner. If i remember correctly there are a few threads that discuss maintenance of these units. A search should give you some info and you might find info in the in the FAQ section.

The MAF is the hard plastic tube with wiring going to it just after the air cleaner housing. It has a tiny bare wire inside it that get's dirty. You can pick up a can of MAF cleaner spray at any auto parts store, then just hose that little wire down until it's clean. Give that a shot and see if it helps. I clean mine about once a year.

 

[Gafjz80]

I had same issues. Intake hose was in two pieces. Replaced it and fixed issues.

 

[prossett]

94SRUNNER, you're absolutely right - thanks!

It's the Air Flow Meter, AFM. My mistake. For the 1994 LC-80.

Intake hose is fine, good advice as that happened once and hose was replaced.

Looks like this (wire optional)

Topside

Might as well open it up and have a look-see.

Excellent weather proofing.

Underside with plate removed.

Topside with plastic cover removed

As the mechanical air flap turns, pushed by the air flowing through the intake, the electrical thingamagiggy on top turns along the black ziggedy line where you see the two + signs.

Not much I can do as the mechanical parts seem to work ok. Spring has good tension, and everything turns as it should, it seems.

So I'll clean the copper contacts and see if that does the trick.

Here's the connectors, but they look clean and good:

Was hoping to find some corroded parts I could blow on and seal back up, but the weatherproofing on this 20-year-old part is fantastic, and there's no sign of any corrosion in the least. Looks brand new.

Any suggestions while it's opened up?

 

[TrickyT]

The "connector" you show has been ripped off the circuit board shown in the prior picture! You should never remove the screws securing the connector to the VAF housing. The 3 wires with terminals can easily be reconnected to the metal tabs on the black connector, but the other 3 tabs must be soldered to the VAF circuit board. Unfortunately, this screwup is way too common. Many photos on other 80-series threads if you do a search. If you are good at soldering this is fixable, otherwise you need a new VAF.

 

[prossett]

Ah so deska!

I see!

I'll solder them back on... if I can find the problem... but no

Haynes says resistance at idle should be 200-400 Ohm, and at full throttle between 20 and 1,200.

At idle:

Full throttle:

And a little confused at mid-throttle:

Time to flash out the visa card

 

[jakesiar]

I would try what TrickyT mentioned… I had one that I needed to solder and it works perfectly.

 

[FJEighty]

The "connector" you show has been ripped off the circuit board shown in the prior picture! You should never remove the screws securing the connector to the VAF housing. The 3 wires with terminals can easily be reconnected to the metal tabs on the black connector, but the other 3 tabs must be soldered to the VAF circuit board. Unfortunately, this screwup is way too common. Many photos on other 80-series threads if you do a search. If you are good at soldering this is fixable, otherwise you need a new VAF.

Would you know where to purchase a VAF circuit board?