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When I bought the car the stock airbox was bolted in. The MAF has the numbers 83191172559 but it could be that there are a few numbers at the beginning missing (sticker is scratched) Can anyone tell if this is the stock MAF? Kinda strange because when I browse for the Delco MAF I see a plastic part...
Also got the Moroso CAI and a Grantelli MAF (89873872257, should be optimizer for the CAI?) with the car. Is this any good?
don't use the Granatelli MAF, period. The arrow on MAF should be pointing towards engine if it is not. It should also have the screen in it
tried the Granatelly yesterday and today but due to bad reviews here I decided to put the other one back in because its my daily and has to work without problems
The Granatelli can be "made" to work but requires PCM programming and in the end provides no gains so just use a F-Body GM MAF. The screen is to "uniformly stabilize" the airflow across the wire sensors so you want to keep it in vs removing.
thanks for the advice!
you donˋt happen to know what kind of maf the other one is? i mean if it is a stock delco one then there should be delco written somewhere, or am I wrong?
I have the original MAF sensor from my 1994. The number under the barcode has 11 digits, so it looks like you have the complete number. The number on mine is 82410121129. And no FLOW arrows. But otherwise the appearance is identical to your photos, assuming the inlet side of yours still has the screen in place.
As I recall, there was a change made sometime after 1994. The 94 has a spring ring in a groove holding the screen in place, making it easy to remove without damage. The later version had the screen fixed in place, in a way that requires destruction of the screen to remove it. That may account for the bar code number being different. But neither bar code (yours or mine) seems to tie into the actual part number.
In any case, do not remove the screen. It affects the calibration of the sensor. Mail order tuners don’t want to see a screen removed.
As I understand the Granatelli MAF, the electronics were modified to under report the actual air flow.at very high flow levels. That leans out the A/F ratio at peak RPM, where the stock tuning sets it on the overly rich side. Problem is, the modifications didn’t seem to be reliable, and often they cause more problems. I haven’t seen anyone even mention the Granatelli for at least 10 years. Leaning out the too rich stock target A/F is easy to accomplish in the tune - something a DIY tuner can do using calculation formulas available online. Or a mail order tuner. Good for 10-15 HP.
Shoebox shows the various part numbers for the MAF.
Current listing is:
Purchased from AC Delco parts supplier - 213-4657
Purchased fromGM dealer - 19207203
Previous GM parts listings -25179711 and 25008308
I looked again at my MAF. On the edge of the black plastic rectangle there is another number cast into the plastic. Hard to read, but appears to be:
94200 0240 2
That might be a production number, example 200th day of 1994. That would be sometime mid-July, and my car was built on July 27.
I peeled the bar code label off, nothing under there. I took the sensor apart. On the metal ends there is a date code involving dots in a box and the number “94”. The inlet half with the screen has part # 25008248, the otherhalf is 25008249. The numbers are way down inside the dividing wall. There are a few seemingly random 2 and 3 digit numbers in triangular reliefs on the mounting surfaces of the metal ends.
No additional numbers on the plastic sensing element that I could see..
As far as the Granatelli, I personally, would not use it. In theory, it works, but the results people have had are hit or miss - you might gain power, you might lose power, or it might just make the engine run rougher. There’s no way to determine if yours is working without some sophisticated dyno testing. If you simply use the stock MAF, and have the PCM programmed for a leaner target A/F ratio in power enrichment mode (roughly “WOT”), you will have a known, positive result. Many people with basically simple (or no) mods get a tune for this reason. If you have more significant mods, it’s mandatory. With tuning software, it’s one of the easier changes to make yourself.
I looked again at my MAF. On the edge of the black plastic rectangle there is another number cast into the plastic. Hard to read, but appears to be:
94200 0240 2
On mine there is something also, but very unreadable.
I put the Granatelli back into the box. Probably putting it up for sale over here.
Look inside of the dividing walls..... they are hollow on the surface that fits up against the plastic sensing element. Way down in the bottom of the wall is a part number. Each 1/2 has it's own number. The last 3 digits of the part number in the casting is different than the part number shown in Shoebox's list, but the fact that they all start with 25008 would seem to indicate that the part numbers on the castings are sub-part numbers for the complete assembly.
Previous GM parts listings -25179711 and 25008308
You just need to remove the 4 bolts that hold the assembly together. Mine are T27. It only reassembles one way, but I would number the parts in sequence, on one side of the assembly, to assure you get it back together correctly. I needed a shop light and a magnifying glass to read the numbers inside the castings. Just be very careful handling the plastic sensing element.
I think the T27 is also used on the fuel pressure regulator. There are 15, 25, 45, and 55, but only one source that I am aware of for a 35.
Wait 'til you try and remove a seat belt anchor.... it’s a T47, which I believe is a proprietary GM size. I found one so I could remove the stock belts, and use the same anchor for the belt portion of a 5-point harness.
10-13-2019, 02:44 PM
