quick question, MAF compatibility

[lilvtboigotrice]

well basically my car has been in on and off limp mode for quite some time now and basically I need a new MAF pretty quick. I have a MAF from a KA24E and question is if i could replace it with my broken KA24DE MAF? i tried searching but came up with nothing and thanks in advance

[lilvtboigotrice]

bump, anyone?

[:: orion ::]

No...

MAF must match the ECU...

'89-90 requires SOHC MAF

'91-94 requires S13 DOHC MAF

'95-98 requires plastic S14 MAF

- Brian

[crypt2k]

I heard they used differrent manufacturers also... Does that matter? Or can you just match the maf and ecu of same year?

[lilvtboigotrice]

That's kind of weird because we did something different. At first the connections were different but we modified the adapter to the KA24E MAF so now we are using the KA24E MAF with the KA24DE ecu and the car is no longer in limp mode and I get 7 more mpg because previously I was only getting 16 mpg average. I don't see the engine light on so is this okay or will there be a problem in the future?

[crypt2k]

oh yeah?

thats sum good **** then.

[lilvtboigotrice]

thats sum good **** then.

uhh...do you mean that in a insulting way or good way? kind of confused about that

[crypt2k]

i dunno how you mistook that for an insult....

let me rephrase... in a more civilized way....

"wow, that worked?... thats great then."

[:: orion ::]

Not so much a problem...but the voltage curves are quite different...you're probably running lean, hence the good mileage.

And as long as the ECU sees MAF voltage, it won't throw a code, so the no CEL is not a surprise.

So if it works and makes the car run...good for you, but your results are NOT typical, and not the correct fix.

- Brian

[crypt2k]

time to re-alive this thread...

heres my problem. I have a '90 240 with a 91 kade... since the transplant the car has run like ****. Took it to a shop and they told me the MAF is bad, so i have to buy a new one. I searched for one and found one... only thing is that the numbers on both of them dont match.

mine reads:22680 52f00afh50-136311

the one im buyin reads:22680 40f00afh50-040305

they are both made by hitachi...

will the new one work... or is the one i have on even the correct MAF for the engine?

thanks beforehand guys.

[JRL]

Your MAF operates on a 64 bit (x axis only) grid. As more air passes by it, your ECU will read farther down the grid and then translate the given value into a voltage reading.

I just compared the 2 VQ maps (Maf maps) (DE vs E).

The first few points on the grid the E MAF has nearly double the value as the DE maf.... This is at idle, and it reads the same value for the 1st 12 points....so sitting still the E MAF may not be so good for your gas mileage.

But, from then on, the DE MAF reads nearly double the value of the E MAF up to about point 25 on the MAP....So, there is a chance that you will run a little lean from point 12 up to 25 or so.

From then on, they read very similar values (with in 100 points of each other, seeing as how they can read up to 60,000 points). Although it looks like the E MAF reaches it's max a few points earlier than the DE.

They look confusing, but, when there put in a straight line (like an X axis) they make a little more sense, and, you can see kind of whats going on.

Heres the KA24DE VQ MAP: 7,25,51,86,129,178,235,298,368,446,542,646,773,922,1120,1350,1535,1766,2052,2331,2635,2978,3355,3753,4173,4620,5100,5619,6171,6772,7433,8145,8899,9696,10553,11468,12454,13477,14556,15710,16958,18240,19583,20988,22481,24046,25693,27398,29157,31081,33088,35147,37214,39361,41589,43899,46294,48774,51341,53997,56742,59579,62510,65535

Heres the KA24E VQ MAP:320,320,320,320,320,320,320,320,320,320,320,320,370,450,560,700,880,1090,1350,1640,1970,2340,2760,3220,3720,4270,4860,5490,6180,6910,7680,8510,9380,10300,11280,12300,13370,14500,15690,16930,18230,19590,21030,22530,24100,25760,27510,29340,31280,33330,35500,37800,40240,42840,45620,48580,51740,55140,58770,62690,65535,65535,65535,65535

[crypt2k]

anybody got an answer to my question?