MAF (AMM) Woes and Q's

Over the summer I had finished up my LH2.4 Swap into my 83 242 and I used the MAF I pulled from a 91 740 donor (Bosch 0 280 212 016) I noticed that when I really got into the boost (10+ PSI) the car would lean out (AFR ~14) but if I progressively accelerated or held boost for longer it would get richer (AFR ~11.5)

I searched through the forums and found someone with a similar issue and they mentioned this phenomenon changed when they replaced the MAF.

Fortunately I had a spare cheapo fleebay MAF I bought for my 91 240 wagon as a spare so I plugged this thing in an viola! No more fluctuating AFR's under boost (AFR ~ 11.5 - 12)

Not wanting to rely on my cheapo MAF I spent the big bucks and bought one from FCP - an original Volvo one . . . . which is now made in China

I installed this into the car and it started to run poorly. It was pig rich at idle (ARF ~10) and under boost at 12- 15 PSI.

After diving the car for a while the idle AFR's did improve but the car seemed to perform better with my spare Fleebay MAF.

One of my questions is does the ECU relearn when a new MAF is installed? Should I have disconnected the battery before making the swap?

On a side note I am running wasted spark and sbabbs chips on the EZK and ECU and I do have a 3 bar FPR.

Thanks

I think the reset by removing the battery is a good idea. If it still acts weird I would get a warranty replacement.
The original AMM is a Bosch unit. So what you are writing is the Bosch unit is made in China or the replacement volvo one is no longer Bosch and is made in china?

The replacement (OE Volvo) unit is no longer bosch and it has a sticker on it which says it is a replacement for the 016 AMM with made in china on the sticker.

Well at least it comes with the FCP warranty. Hopefully it will behave better with the reset.

NOS NIB Bosch or genuine Bosch factory remanufactured exchange, everything else is garbage except perhaps the few OG ones that are still working since new.

dl242gt said:

Well at least it comes with the FCP warranty. Hopefully it will behave better with the reset.

Click to expand...

I tried the reset and it seemed to help. Afr's are low when cold but hit mid 14's after a minute or so of idling. I did a few WOT's and at around 16 - 17 PSI of boost I am seeing high 10's -low 11's AFR and heard no pinging nor did it feel like the engine was bogging.

Squawked the tires in second gear a few times too.

I am going to run with it for now.