OK, I bought an official Volvo MAF sensor a few months ago hoping it would help with problems with my car, but it really hasn't helped much. I've gotten a 3-1-1 code ever since I got it, but because I paid almost $200.00 for it, I didn't want to believe it's bad, and the car did run better for a while. Why did I make such a dippy assumption? Well, the new one looks different from the old one, despite being the *exact same part number*. The old one had what looked like a fork in a round wind tunnel with some very thin wire strung around inside, and I have seen another type that has an oblong wind tunnel and a thin wire shaft (I think...) sticking up into the air flow space. The one I have right now has a circuit board inside a round wind tunnel, no wires to be found, so when I get a code that says "Wire Burn-off Signal Missing or Faulty" then I start thinking...

So my question is: Is there a difference between these types that can be specified when ordering? The OE part numbers on all these are the exact same; it would be nice if I could ask the parts house if they have the correct part without demanding they open up the box and describe what they see.

 

Is your code 3-1-1 or 3-2-2? 3-2-2 is Air Mass Meter wire burn-off signal absent or faulty. 3-1-1 is a missing signal from speedometer and can cause some drivability problems but is not related to the MAF.

Looking at what Volvo branded MAFs for the 240 are today and it definitely is not a Bosch product (originals were all Bosch). That may explain why it looks different. Doesn't look like new Bosch-brand replacements are available anymore.

 

Oof, this is what happens when you post way past your bedtime.

Sorry, 3-2-2 is the correct code, and I'm also getting a 2-3-2 whenever my wife reports it is dying after starting when she takes it to the grocery store. I don't notice much because when I drive the car, it's down the road and onto the freeway, so I don't get the same symptoms. In testing it last night, I tried starting the car with the MAF socket unplugged. It ran better than plugged in! So that's the reason I'm looking for a replacement is because I am finally ready to accept that the MAF is bad, and may have been bad from the get-go (and it's been too long for me to ask for a refund or replacement), but I'm also trying to source the "correct" MAF so I don't get the 3-2-2 code any more.
O'Reilly has remanufactured MAF sensors that look like what I'm talking about: Part number MF2044. I've had pretty good luck with reman parts before, so I'm OK with this particular one, as long as it is what is portrayed.

That said, did the original Bosch units look like that? Is there any documentation anywhere that the new ones don't require the wire burn-off function? Or do I simply have a bad one, and the circuit-board-in-a-wind-tunnel types work just fine?

 

I don't know what O'Reillys sells as remanufactured parts but I would purchase from some of the parts stores online that focus on parts for Volvo such as IPD, FCPEuro or EEuroParts. IPD will sell you a Volvo branded part but they also have a 3rd party manufacturer. Both of them are made in China so I can't vouch for the quality. All should avoid the 3-2-2 code.

Just out of curiosity, have you defeated the hot air intake in the air cleaner box? The main cause of MAF failure in these cars is the thermostat goes bad in the air box causing the hot air from the exhaust to be flowing all the time. Many people wire that intake closed so as to not fry the MAF.

 

In my experience MAFSs can be tricky and often the source of seemingly unsolvable problems with our cars. Many shops misdiagnose them and hunt for other issues and that goes on for ever. It doesn't help that the MAFSs act up often intermittently and with various driveability issues affecting CEL and the OBD in strange ways. At this point in the life of 25+ year old cars it has become a gamble when sourcing a good replacement, especially when a new or rebuilt sensor can be just as faulty. I've had to go trough as many as four MAFSs before I got a good one! Frustrating to say the least!

 

The MAF that I have now is a genuine Volvo part from IPD. O'Reilly sells a few different ones, and I did my research; the one I ordered looks like the old Bosch units with an actual wire strung inside the wind tunnel. The one I have now has a weird circuit board sensor thing. If the 3-2-2 code is calling for a wire to be heated, I'd think you want a MAF with an actual wire in it.
The pre-heater hose from the exhaust manifold to the air box is disconnected, so that's not a concern.

 

I thought I had a MAF that was going bad recently. When unplugged, the car would run better just like you were mentioning. I bought a remanufactured Bosch MAF and it really did not make much of a difference. I started hunting around for other causes and I discovered huge vacuum leaks that I hadn't noticed previously. I didn't see them until I took off the hose that connects the MAF to the intake. It was cracked in multiple places on the back side.

 

I have a brand-new accordion hose, and a bunch of other hoses. The only hoses I haven't replaced are the ones from the flame trap to the accordion, and from the IAC to the accordion, but I've checked both of those; no leaks. Well, it was last year that I checked, so maybe I do need new hoses, who knows. All I know is when I push on the gas, the damn thing just doesn't go. It'll either mosey on up to full acceleration after a second or two, or it'll sit and sputter and suddenly spring to life after I pump the accelerator a few times. It's really driving me insane.

I just this afternoon replaced the MAF with a remanufactured Bosch-style with the wires and the little blade that sticks up in the wind tunnel. Now it idles fine, but the acceleration is worse. But the best part? NO ERROR CODES!! I now get 1-1-1 after driving it around town, on the freeway, no matter what. And it has stumbled, spit and wheezed at almost every damn stop sign and traffic light I have to stop at, and even backfired once or twice. I have replaced every damn thing I can think of but the injectors, and I really hope that's not the problem because I can't get the fuel coupling on top of the engine to come apart (which I tried to do when I attempted to measure the fuel pressure).

I can't afford to have a professional look at it, but it's becoming very tempting. I can swing a few bucks every other paycheck to throw at the problem, but I am losing patience. I don't have another car to drive while I tinker with this one, It's my only car and it just has to run.
Ugh...

 

Time to revisit this thread...

OK, the MAF I bought is NOT the one I needed. I've been through fistfuls of websites, pored over seemingly hundreds of photos and I have finally come to a conclusion:
The MAF I need is a Bosch '0 280 212 016', and these seem to be rarer than hen's teeth; every source I've been able to pin down, including remanufacturers, EVERY ONE of them will say the part they are selling is a part-for-part replacement for the one I want. WRONG.
I've done what I said I didn't want to do in the first thread and called up auto parts stores that say they have a remanufactured unit in stock and I ask them two questions:
1- Does it have the EXACT part number stamped on the side?
2- Inside the unit, does it have a 2-pronged "pickle fork" holding the wire inside the wind tunnel?
If both of those are true, or at least #2, then I have the right part. So far, none of them have been.

I called a parts store 50 miles away because they had the correct Blue Streak Electronics remanufacture (MF20044N) of the Bosch part, but when I asked them to look inside, it did not have a "pickle fork", but one blade sticking up, which is exactly like the one I have now, which is the wrong part. I ordered a Cardone part no. 74-10017, which shows abundant pictures on the website, and a description that says explicitly that it is a remanufacture of the afore-mentioned Bosch part, but when I opened the box in the store, it was a Bosch "0 280 213 004" instead, and is exactly like the one I have in my car right now, and I guarantee, it is not fully compatible with my car.
I ordered one from a guy on eBay that had pictures and everything, I get it and it's actually part number Bosch '0 280 212 015'. Yep, one number makes a BIG difference.

WHAT THE HELL? What kind of shoddily-run company do you have to be that you can't look at YOUR OWN SPECIFICATIONS and send out a part that matches? It would be one thing to have to buy multiple ones until you find a good one, but it's an ENTIRE THING ALTOGETHER for it to simply be the WRONG DAMN PART every damn time.

Sorry for the rant, I'm just very frustrated right now. But by the way, does anyone here know FOR SURE where to buy a Bosch 0 280 212 016? Even remanufactured, I don't care, I just want to know that the part I'm buying is the correct one. I've checked the local Pick-n-pulls, the closest one that has a '90 Volvo 240 is over 3 hours drive away. Not gonna do that just to find out it's the wrong part or it's missing.

 

Interesting, I haven't run into this number/prong dilemma before. I have only dealt with MAFS which were bad and I had to go through several until one was good. I wouldn't think the shape of the inside prong would matter, it's just a probe after all, the numbers, yes, they are important but the shape of the sensor? Good luck in your MAFS seeking adventure!

 

I only mention the shape of the sensor and the number because that's what I have found in all my research to be the "correct" part. The '0 280 213 004' certainly fits, but it obviously doesn't work. I looked it up in a cross-reference, and it is a MAF Sensor for a Corvette! Why such an obvious mis-match would be sold as a compatible item, I cannot fathom. I mean, it's printed right there on the side of the thing! And I have already thrown money away on this car, I don't relish the thought of throwing more down the drain hoping that I get a "good" one this time.
I'm going to call a bunch of local wrecking yards today and see what they have.

 

No luck with the yards. Ugh.

Lev, out of curiosity, do you have a 90-93 240? If so, and your MAF works, what type is it? As in, what does the sensor look like? Maybe if I can find a reliable source of a type that DOES work, even if it's different, I can finally stop considering rolling this thing off a cliff.

 

I just sold a '93. Yes, I had a MAFS problem totally misdiagnosed by the local shops' gurus who swore it was the ECU. Finally I swapped all ignition components and another MAFS did it--immediate response, the car ran as it should! I don't remember the number, I was always under the impression that ALL b230, NA or turbo, had the same MAFS after 1989 so I had a few spares.

 

is this what it looks like?

https://www.ebay.com/itm/1984-1998-V...-/293700326711

 

This is the number I have used for 1989 and newer Bosch b230, NA or turbo. But this number does NOT work for cars prior to 1989 as the listing claims. This particular one looks like it had been resealed at some point, probably rebuilt, and no way to know if it's working. I suspect that many older Volvos are junked due to the bad MAFS unable to be diagnosed correctly...

 

anything is possible, but for what it's worth i have had some good luck with ebay lately getting parts and also
getting refunds for parts that needed to be returned for one reason or another....

 

Yes, that is the exact one. I already have two coming this week or else I'd order the one you listed. I'll remember it in case the ones I ordered don't work out.

 

The one I ordered from eBay came. It had the right part number, but once again it had the wire and fin, instead of the fork. "Heck..." I said to myself, "the worst that can happen is it doesn't work, and the one you have now barely works at all". So I gave it a good cleaning (it was narsty...) and installed it. I had the battery disconnected while putting the thing in, so I had a fresh start in the ECU.

You guessed it... Perfect acceleration from all stops, up every hill, all over downtown, for an hour or two, and the same thing the next day going to work and back and a few stops afterward, and no codes reported.
Damn.
So I was wrong that it has to be the one certain kind, I guess the ONLY criteria are;
1- Does it fit?
2- Does it work?
Whether aftermarket, NOS, or used. I'm just glad I finally have one that works.

Thanks all, I'm going to bed now.

 

My experience exactly. Once you get a good one, you know it immediately! And the shape of the element doesn't matter, it's just a probe. Glad you gotta a break after all the frustration you had to go through.

 

I was a bit groggy yesterday when I posted, I should have thanked you personally Lev, I originally was skeptical of your observations, but they turned out to be quite true. My apologies.
As I mentioned before, I guess I didn't want to admit that a part I bought for $200 would be faulty on arrival. I still believe that the "Genuine Volvo" units with the little circuit board in the wind tunnel are not correct, and I've read on other forums people having problems with those particular types and the 3-2-2 error, as there is no wire to "burn off".

Though I may turn out to be wrong on that one too...