Code 33 MAF

stwrt83 · 02-25-2002, 09:06 AM

This Weekend I installed a BBK 58mm Throttle Body on my 87 IROC L98. It ran great for about 30 minutes then It tripped a Code. 33 MAF. I checked all of the connections, and everything was tight. If I reset the computer It ran great again, but after about half an Hour the SES light came on again. After the light came on, it ran like there were a couple of plug wires crossed. What should I try next? Has anyone else had this problem? Any help would be greatly appreciated. Thanks
Nick

AngelicTorment · 02-25-2002, 09:16 AM

Dude when and if you get that fixed tell me how that new 58mm works out for ya.. I thought about buying one just havnt talked to anyone whos put on in yet.

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1987 Z-28 Iroc-Z,305 TPI
Dual Ram-Air w/ K&N filters and ported "intake Y", Bosch platinum plugs, w/ 10mm wires, removed airpump(belt) and A/C pump ( who needs it I have windows and T-tops

), March underdrive pullies, 10degree timing, throttle body by pass, 170 degree thermostat. And some cool looking red pedals...lol Thanx Teke._ ________________ _ Future mod. True Dual exhaust. Straight pipes no Cat and no muffler. heheheh

aklim · 02-25-2002, 10:20 AM

When my buddy with a Mustang changed fuel ijnectors, TB and stuff like that, he had to change the sampling tube at the MAF.

I believe that as more air passes thru it, it cools the wire in the MAF more so it requires more current to keep it heated. The current draw, I believe, is the way the MAF senses how much air is going thru. Because you have lowered the restriction, more air is going thru and as such, if my belief holds true, it is saying it has sent more current to keep the wire at a certain temperature than what the chip tells it is necessary for that engine speed.

stwrt83 · 02-25-2002, 01:30 PM

How would I change the Sampling tube?

Thanks,
Nick

[This message has been edited by stwrt83 (edited February 25, 2002).]

tpibubba2002 · 02-25-2002, 09:30 PM

Surely have to adjust the idle set screw, TPS and IAC. If you just swapped everything over and didn't adjust anything that will be a problem. Been there done that.

stwrt83 · 02-26-2002, 01:26 PM

TTT

stwrt83 · 02-27-2002, 02:06 PM

TTT

whinton87 · 02-27-2002, 02:24 PM

Hey Man

I had the same problem with my 87 try seeing if everything is ok with you TPS See if it is in specs then give me a write back at whinton@excite.com to see if that works.

Later

stwrt83 · 02-28-2002, 01:22 PM

TTT

Glimmer · 07-31-2002, 12:37 PM

I recently chaned to headers on my T/A GTA -88, and after this I got this strange problem:
The car runs just great and the SES does not turn on BUT, when I connect my Xray it gives: 33 MAF/MAP sensor too high.

The MAP-sensor reads 2.58V on idle and the manifold air temp is 125.6*F

Anyone know what it could be?

Thx
/Andreas from Sweden

Sciguyjim · 07-31-2002, 03:07 PM

Quote:

<font face="Verdana, Arial" size="2">Originally posted by aklim:
...Because you have lowered the restriction, more air is going thru and as such, if my belief holds true, it is saying it has sent more current to keep the wire at a certain temperature than what the chip tells it is necessary for that engine speed.</font>

I agree w/Aklim, the airflow is probably outside the MAF's calibrated range. If you've removed the screens from the MAF, this would add to the problem.

Glimmer · 08-01-2002, 06:30 PM

Could this have to do with that I took away the cat? Before there where a (air?)connection to it from beside the throttle that I cut off since I don´t have the cat anylonger.

Sorry about the spelling, I don´t know the words for it in English.

Thx

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Pontiac T/A GTA 350 (L98)-88,TH700, TransGo shiftkit, Edelbrock headers, Holley adj fuel reg, Accell SuperCoil and 8.8mm spark, no cat´s,JR airfilter

SMaster · 08-04-2002, 12:07 AM

Quote:

<font face="Verdana, Arial" size="2">Originally posted by stwrt83:
This Weekend I installed a BBK 58mm Throttle Body on my 87 IROC L98. It ran great for about 30 minutes then It tripped a Code. 33 MAF. </font>

You are hitting the 'MAF High Diagnostic Error' limit programmed in the ECM. It's been a while but I had to change mine from 45 gm/sec to 50 gm/sec to get it to quit setting the code.

I haven't read the hack/code but it's probably comparing the TPS with the airflow so maybe. . . and I have no idea if this will work but try setting the TPS a little higher than it is, say to .60 or so at idle (0% throttle) and then reset the minimum idle and see if it helps.

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SMaster