using the tip I gleaned from this board, I took out my MAF screen, and now the car's idle is rough and the SES light comes on! help!

 

I dont have a Maf on my car but suspositly thescreen dosent make a diffrence dd you try putingthe screen back in?

 

woahhh....screen DOES make a difference. btw..once u take that screen out, u cant put it back in correctly. I tried thousands of times b4, ended up paying for a new one. BTW...i dont think anyones recommended doing that for some time.

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1989 Firebird
2.8 v6, t5 swapped in

Ram Hi-po clutch, Cold Air, 1.6 rockers,Lakewood LCA's, Lakewood Lift bars, Wonder Bar, 3" y-pipe, Random Tech Cat, 3" I-pipe, Flowmasters, MSd 6a, MSD Coil (Fireball in future) Accel 8.8 wires, MSD Ignition Module, Auto Meter Gauges (Water, Clock (needed one) Fuel Pressure, and 5" monster tach) 4th Gen Seats


" I'd rather run last in a full out race, than to NOT run at all ".

 

U should have asked every1 before doing that. U need a new MAF.

A 2.8 V6 doen't need a modded MAF at all, it flows lots more air then it will ever need already.

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89 RS

Looking For:
87 IROC-Z28 350 TPI

 

"A 2.8 V6 doen't need a modded MAF at all, it flows lots more air then it will ever need already"

uh, not to be off topic, if gets plenty of air, then why are people using the K&N filters, etc?

anyway, I'm going to put the screen back in and see if that works (I was REALLLY carefull taking it out, just in case I had to put it back in back in)

 

Ok, before I or some1 else goes into this, how much do u know about how much MAF's and ECM's so I don't have to say things u already know??

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89 RS

Looking For:
87 IROC-Z28 350 TPI

 

i don't have a MAF so i don't know a damn thing about them but my guess is that since you removed a SCREEN that is supposed to PROTECT the internal parts of the MAF, you've damaged the MAF. it's very sensitive. why else would it have that thick a$$ bee hive-lookin screen.

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Dan
1990 3.1L RS
80 Series Flowmaster
It's fast(er than a 3 cyl metro)

 

HAHAHAHA!!!

 

My GM Service book says that the screen is there to "smooth airflow over the sensor". Seemed to be true when I removed my screen (with stock intake ducting) and got a service engine soon light for "low airflow over MAF".

I've yet to try screen removal with my new "straight-shot intake ducting"... maybe I'll do that this weekend.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

go ahead and presume I know almost nothing. (if it helps I do know how thermistors work, and that the MAF uses one). I won't be insulted, I just want to learn.

By the way, I put the screen back in, and it's running normal again.

 

WEll The TPI, LT1, and LS1 cars respond well to taking out those doma screens. They don't smoothe the airflow its a protection for the MAF that is very uneeded.

I have modified the MAF in 2 305 TPI cars and a 97 LT1 car. HAd no problems with th maf after that and had one of them for 20,000miles of service with the modded maf.

Check your code and see what it sayes. My MAF plug liked to fall off a lot on the 355, and the car would not run at all sometimes and others it would, but would run like total crap.

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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

Usually if something is there, it is there for a reason. Although it might take off .0000000003 seconds off your ET, would you rather buy a new MAF if something happens to damage the sensor (yeah, it's a longshot since the sensor is behind the filters, but oh well). Plus, who likes driving with the SES light on at night? That thing is bright!

Vman

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1969 Camaro Sport Coupe
383, 700R4, leather, everything black but the lights

Previous owner of an 89 RS Camaro
2.8L V6, 700R4

 

'88RS, your MAF shouldn't have a thermistor inside. The MAF's with those had the 5-pin connector, yours has 3.


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

hmmm, mine had a small yellow component that looked suspicously like a thermistor. I'll check the part number and pins tonight.

 

LOL, thats not what I meant, its just that I, and others have got into this so many times on the TPI board I just didn't want to say it all again if u already knew some stuff.

The stock MAF flows enough for a lightly modded 350, much more than what a 2.8 needs,(more than enough for stock 350 engines) and a modded MAF will flow more than 700 CFM when the stock ECM will only measure around 500 CFM anyway. Sometimes too much airflow isn't so good. U put the screens in again, but u will probably need a new 1 anyway, if it works though, cool.

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89 RS

Looking For:
87 IROC-Z28 350 TPI

[This message has been edited by IROCZTWENTYGR8 (edited May 15, 2001).]

 

Hmm.. Iroc, it seems you neglect to mention the V6 cars use a different MAF than V8 cars. It is tiny in comparasin and vastly inferior as far as airflow is concerned. Our screens also look more like a radiator than V8 screens (as Tom mentioned, v6 screens are designed to smooth the airflow). I have never seen MAF damage or failure from a screen removal. The rough idling for v6 cars, however, is a very true thing. While our MAFs are inferior to v8 mafs, they still flow way more air than we need.. the only way to get an accurate MAF reading is to accelerate and smooth the air flowing across the thermostrip. With the screen off, the MAF's thermostrip doesn't get an accurate reading from the incoming butt-slow air at idle. In fact, it gets a distinctly low reading.. It's not usually a problem at higher RPMs, though the reading is still generally innacurate and will cause the ECM to work overtime correcting the mixture. Your car will probably die at idle when you really don't need it to, throttle response will be lagged, etc. Anyone know of a performance MAF for the 2.8 to cure these woes?

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'86 Camaro SC, black /w silver racing stripes
2.8l MPFI/700r4 /w special 2nd gear delete option
In search of new v8 engine & transmission, now contemplating t5 swap to get me out of this mess.
Misc Mods: Cut air box, '83 Firebird spoiler.
Performance Parts: MSD coil, Accel 8mm wires, SplitFire plugs, Gabriel hijackers.
Audio Mods: Pioneer DEH-P3000, two 12" Optimus Pro Audio subs in hand-made enclosure each powered by a 260 watt Optimus amp. Working on shaving the box for weight.
My Homepage, with pics.

 

'88, I see what you're saying.. that the thermistor you saw is integral with the MAF? I thought you were talking about the 5-pin MAF's... you know the MAT temp sensor in the airbox? The 5-pin MAF cars (like the front-wheel-drive 2.8 MPFI Berettas/Corsicas/Buicks/etc) had the MAT located inside the MAF. 3 wires were for the MAF, the other 2 were for the MAT.

So we were thinking of different things, I guess. The V6 MAF is the AC/Delco "frequency film" maf. It works differently than the V8 Bosch "hot wire" MAF's. The V6 one has an orange frequency film that vibrates with incoming air flow... low vibe = low freq = low air flow. High vibe = high freq = high air flow. If that freq film ever gets wrinkled or bent, the MAF is toast.

The V8 Bosch hot-wire MAF's use a heated wire. Air flow is measured by the amount of current needed to keep the wire at a steady temp. The more air flow = the cooler the wire becomes = the more current's needed. Less air flow = wire doesn't cool down = less current needed.


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

ok, now it makes sense. without the screen to 'smooth' the air, too much turbulence, and you get wild readings. and the idle goes to @#$!

 

"While our MAFs are inferior to v8 mafs, they still flow way more air than we need.. the only way to get an accurate MAF reading is to accelerate and smooth the air flowing across the thermostrip. With the screen off, the MAF's thermostrip doesn't get an accurate reading from the incoming slow air at idle. In fact, it gets a distinctly low reading. It's not usually a problem at higher RPMs, though the reading is still generally innacurate and will cause the ECM to work overtime correcting the mixture."

This is what I'm saying, "They Still Flow Way More Air Than We Need." While the 2.8 MAF IS different from the V8 MAF, modding it works the same, it will cause the same BS that the V8's get when modded (sometimes), and usually require getting a new 1, thats why I used the V8 MAF as an example because I've never seen or worked with a STOCK V6 MAF because I have a higher flowing 1 with only 1 screen that replaced the stock sensor, so I don't know what it would look like, but doing that works the same they just don't flow as high as V8 MAF's. Guys on the TPI board do this and alot of the time have to get a new 1.

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89 RS

Looking For:
87 IROC-Z28 350 TPI



[This message has been edited by IROCZTWENTYGR8 (edited May 15, 2001).]