TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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After doing A LOT of searching on this website... i found a lot of helpful information regarding code 33.... Used MAF cleaner spray...i checked MAF power, Burn-off, and Fuel pump relays- they're good.... on the harness that goes into the MAF sensor A&B- test light on... D (ignition on-engine not running)- zero volts... C (ignition on engine not running)- 1.1 volts so i checked the B12 on the ecm- got 1.1v
Then i cleared the code and checked MAF harness C- 1.1v and the same at B12 (ecm)... Started the car: B12(ecm)- 3.42v..... let the car warm up to operating temp.. got 3.58v at B12(ecm).. reved the motor at 500 increments upto 2500rpm when down to 3.40v.
is there anything else i should check, maybe the TPS ? Or is my ECM on the way out ?
Well it sounds like you might have found the problem already. A&B are both grounds (ones an analog ground to the comp and the other is a regular ground). So its strange to me that the test light would be on. How exactly did you test them? Just dissconnect the harness and put your test light from A to chassy ground and then test b to chassy ground? Next thing is at idle the voltage from the MAF sensor should only be around .5 volts and increase when brought up to 2500 rpms. So ide double check thoes grounds and then look at getting a new MAF sensor.
Ok Well if you followed that flow chart exactly then ide say your down to a bad MAF. What that code is really complaining about is that the output from the MAF is to high given the RPM and the TPS sensor output. That being said i dont think its a problem with anything else simply because the output signal youve measured just simply isnt right. It should be about .5 at idle and go up to about 5 v at WOT. Yours is like 3.5 at idle and roughly stays the same with changes in RPM actually goes slightly down with an increase in RPM. So all and all i think its a MAF problem unfortunetly.
Ok Well if you followed that flow chart exactly then ide say your down to a bad MAF. What that code is really complaining about is that the output from the MAF is to high given the RPM and the TPS sensor output. That being said i dont think its a problem with anything else simply because the output signal youve measured just simply isnt right. It should be about .5 at idle and go up to about 5 v at WOT. Yours is like 3.5 at idle and roughly stays the same with changes in RPM actually goes slightly down with an increase in RPM. So all and all i think its a MAF problem unfortunetly.
does that mean that an improperly adjusted TPS could manifest itself into a MAF code? i too am troubleshooting a code 33 problem
i ended up buying a new multimeter.... and followed the tree diagram again... i got proper readings... the MAF was bad... the tps was at the right setting
does that mean that an improperly adjusted TPS could manifest itself into a MAF code? i too am troubleshooting a code 33 problem
It is plausible that a bad TPS could set a code 33 as one of the conditions a code 33 looks to is the TPS sensor. However if that sensor fails it is unlikely that it will fail in such a way that it would not set a TPS code. However it is a condition that can be easily checked for by measuring the output of your TPS sensor.
