Well i bought a 1987 irocz 305 tpi about 10 months ago and I have been trying to restore it and fix it up. It has good power to be mostly stock except for the exhaust its flowmaster. But ever since i have had it i get a code 33 or 34 or both and it runs like crap. I can cut the car off and restart it and it will run fine for a while. I have change the ecm, mass airflow sensor, tps and almost all the relays and the o2 sensor none have had an affect. I was going to get a new motor but I want to know whats causing my trouble code first before i spend money on performance and still have the same problems. I know i may need to adjust my tps but it was doing it long before i changed it so i think it may be in the wiring. Hopefully someone has had the same problem and has solved it:hail:

 

according to my code book your 33 and 34 codes point at the mass air flow sensor. is it new or are you getting it from a junkyard. then you might want to also check and make sure that the wiring is secured nicely where it belongs. mine had a few bent pins and i replaced the plug no problems since.


-earl-

 

Make sure you check the continuity of the wires that go from the ECM to the sensor, use a service manual to determine what wires they are at the ECM connector and use a multimeter to check for a broken or grounded wire, also check condistions of ECM ground wires I belive they are located on the rear of the passenger side cylinder head on the sutd that holds the air injection crossover tube.

 

Have you checked your TPS voltage? Make sure that you have NO leaks in the air inlet stuff. I had a similar problem a few years ago and I raised my TPS a little and reset the ECM and have never had a code since.....


There is alot of threads about code 33 34 too bad that the seach function is disabled, but there is a lot of info about is......

Maybe this thread could help you? https://www.thirdgen.org/techbb2/sho...threadid=156213

 

I checked my tps voltage and it is .61 at idle and i think that is acceptable according to what i have heard. All of my sensors and ecm are brand new I have though about getting some parts from a junkyard but i try to stick with new parts. I did find a couple of wires that look like they did have a small cut on them so i repaired them. This weekend i plan on checking them further its hard to do it because of working all day during the week. After i worked on it today, i did notice a small improvement on performance and on how long before i got a code 33 i got about 15 miles from home then the ses light came on. I stoped at a gas station to get gas and tried to crank it and it took about 4 tries to get it to crank with the gas pedal to the floor. If anyone knows a way to check the the signal from the mass air flow sensor while driving without buying something too expensive let me know please i would like to see whats going on right when i get the ses light on. I dont mind spending money on something like that but i will only use it a couple of times so i dont want to spend to much. It maybe a wiring problem some where thats causing the code 33 but it seems like it would do it all the time. If i need to give more info on my car or anything like that please let me know

 

I had that same prob with my 88 Form 350. I tried different ecm units and mass air flow sensors to no avail along with replacing all the relays, etc. Then one day I pulled out the replacement ECM that only worsened the problem and installed the original one back in. All the sudden everything was fine and has been fine ever since. ??? Don't ask how.

 

https://www.thirdgen.org/techbb2/sho...hreadid=156213

There is also a post out there that will tell you how to do every lead. This is the same thing as GTA324 is showing, but this link works. I took out the "..." that is showing in the previous link. Let us know after you do this.

 

thanks for the info ill try to do some of it today and let you know what i found

 

i tried some of the tests from the thread you recomended my test light is messed up so i got to get a new in the morning but one test said to

turn key on engine off
measure voltage at terminal c to a at maf.
should be 4-6 volts if ok suspect bad maf

well i only was getting .05

it says then to disconnect a and b connectors to ecm and repeat
"i dont know which connectors a and b are so i didnt try it"
it then says in still no voltage then bad ecm but like i said mines new and i know its possible to get a bad one even if its new but i would think its unlikely.

my tps reading is still maintaining around .61 so i think thats fine
i did try to measure voltage from battery to terminal on maf
i did get one reading from c to postive on battery dont know if this is anything or not maybe i am getting power to c but not a or possible a loose connection on a from power source.

well thats all for now i jump on it when i get home so please if any of this info sounds like it might be something let me know i really need some one to explain some of these tests to me if they can
:hail: