Hey guys, iv'e been searching alot but what we need is a list of people who have taken care of their code 33 problems,

so please, anyone who has conquored code 33 by any means, (changing prom code, adjusting iac, etc...) please post all of your proven solutions, im not looking for speculations, i just wanna hear from people who have accually fixed it or know of a way that definatly works.

 

I have an 87 t/a 350 tpi. I was getting a code 33 almost every morning on the way to work, but not on the way home. might have been the colder air in the morning it was october. I replaced maf power and burn off relays and checked every connection in the maf circuit, all the way from the maf itself to the relays to the ecm an so on. all of them were good.

i did have luck adjusting the tps sensor, but to get the code to stop the tps voltage was so high at idle that the car took too long to come back down to 550 rpm while driving when coming to a stop so it felt like the engine continued to pull while you had your foot on the brake before stopping completely, and even after you stopped it would take several seconds for the idle to come down.

I started scanning the car with craig moates software and found that the maf gps were not all over the place, they were consistent with engine rpm and load and throttle position sensor voltage. so i knew the maf wasnt bad. i researched what conditions would throw the code and found that ( this is all from memory) if the gps went over 45 (could have been 40) and the rpm was under 1800 and the throttle position was under 85% you would get the code. my gps would go to 46 or 48 but it didnt spike to that it would go up smoothly with rpm and tps.

so since it was only a few gps above norm i decided i could safely burn a chip to fix it. so then i bought chip burning equipment and learned to burn chips and on my first burn i raised the "maf diagnostic error threshhold" from 45 to 55 have never had the problem since and the car drives great. i have since made other changes to the chip but none that relate to the maf.

sorry for the long post i just wanted to give a coplete account of my trouble with code 33. hope it helps someone else.

 

thats awsome, thanks, has anyone else used the same thing to fix thier code 33?

 

Min idle, Idle TPS position, base timing, IAC routine

Make sure all that stuff is set properly. One or a combination of the above could cause you problems.

 

https://www.thirdgen.org/techbb2/sho...83#post1701483

I set it to 55, problem was gone!

 

The ONLY for sure way to elimenate the 33 error code is with a custom programmed Eprom chip. I set mine at 255, the max flow of the MAF sensor.

The code will be set if you meet three criteria at the same time, even with all known good parts. I posted the criteria stuff last year some time.

You can change parts, like I did. It may go away for a short time, but comes back like the plague. You can play with the idle TPS voltage, like I did, the code might go away for a while, but it will come back like the plague. This one problem with MAF cars is a very good reason to start burning your own chips. The cost to get started is about $220. I spent more than that a new parts in an effort to get rid of this plague. No more problem now!