also what years do MAF work for? I mean will an 88 maf on a 350tpi work on a 86 305 etc??
thanks

 

Ron,

The MAF sensor was the same on Chevrolet TPI engines from 1986 through 1989 models. The early 1985 models used a digital output Delco MAF, and the rest used an analog output Bosch MAF. Any year or engine from '86 through '89 uses the same MAF sensor.

Of course, I have a photo:


------------------
Later,
Vader
------------------
"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

thanks a lot vader

 

Ron,

You've pro'lly already got one of these:



------------------
Later,
Vader
------------------
"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

[This message has been edited by Vader (edited March 18, 2001).]

 

I'm sure it's been said before, don't remove the screen on that thick filmed MAF. I did that before I found this site and my car ran horrible. It had horrible driveability and my ses light kept coming on and going off (depending on rpms) After e-mailing Borg Warner, I realized I would have to put the screen back in. Only problem is, the screen doesn't just pop in and out. I mangled it some to get it out. Anybody ever replaced these screens? (thick film type) My SES light doesn't come on anymore and the engine seems to run good (with mangled screen), but I'd like to put a new screen on if possible.

Barry Izold
89 T/A, GTA
Modified 350/T-5

 

just to make a point, the thick filmed maf come with only 1 screen , unlike the bosch that come with screens on both sides.

 

Ron,

Good point, hopefully I didn't confuse anyone! That stupid screen just looked sooooo restrictive. Live and learn.

Barry Izold
89 T/A, GTA
Modified 350/T-5

 

Ok, I must have missed something. What is the advantage of the thick film MAF? Is that just a replacement MAF made by Borg-Warner?

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'89 Formula 383 TPI

 

Greg,

This particular unit was made by Wells Mfg.

The screens are not necessarily there to keep dirt out of the MAF sensor.

The OEM Bosch MAF sensor has round wire screens mounted in metal rings which actually reduce the straight air flow across the sensor array. The more turbulent air behind the screen will flow through the sensor body more equally, so that the air flowing through the sampling tube will be a more accurate representation of the total air flowing through the sensor. There have been several notable instances of people carefully removing the screens without damaging the hot wire element, and then having MAF errors due to improper flow readings being reported to the ECM. At certain flow rates, the molecules of air tend to flow toward the outside of any curve, and can tend to flow around the sampling tube instead of equally through the MAF body if the screens are removed.

Additionally, these screens protect the fragile hot wire from debris and sonic wave shock caused by lean backfire and wide-open throttle "howl". These sonic pulses could significantly shorten the life of the platinum wire if not deflected.

The thick-film sensor eliminates the hot wire for temperature differential sensing (the way that a MAF measures air mass). The newer GM MAF sensors (LT1/4, LS1, Vortec) use a thick film instead of a hot wire sensor. They also use the flat metal matrix instead of a round wire screen at the inlet side of the sensor body. The Wells unit is of the same design.

The particular sensor in the photo has an inside diameter of 73mm at its smallest point and 78mm at its largest. The stock design (and remanufactured) Bosch hot wire MAF has an I.D. of 70mm.

Other than that, I found the thick film sensor only to be slightly faster than the hot wire in sensing changes in air mass moving through the housing. I guess if you don't mind a little extra hesitation at throttle tip-in and having a fragile, restrictive, and failure-prone sensor on your car, there are no advantages to the thick-film design.

GM must have seen the same things in specifying a different design for the newer engines in 1992.

------------------
Later,
Vader
------------------
"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

Or did WELLS notice the same thing in the new GM stuff?

 

Where can you get one of these thick filmed
MAF sensors, I am in the Vegas area and I
have not found anyone offering them, Auto
Zone said they used to carry them but no
longer, any suggestions ?

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TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 9 bolt 3.23 g92 axle, 4 wh. disc brks.

 

i have one for sale, thats why i asked for the pic and info , email me if interested.

 

RD,

You've been talking to Brian Garrow again, haven't you?

------------------
Later,
Vader
------------------
"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

MY87ROC,

You can also purchase them new at Wrenchead.com. They do list both, so make sure you are looking at the right one. It was under the "high perfomance" listing and make by Borg. Not cheap.

Barry Izold
89 T/A, GTA
Modified 350/T-5