i run a diagnostic test on my camaro and it says i have a code 33 which means the voltage is too high in the maf. now i looked in the book and it says it has an excess of 35 or 40 gr/sec of air to have a code 33 but on the diagnostic tool it says its only 13gr/sec on the sensor. i was originally going to just replace the maf but is it the maf or something else with this error?

 

Check for low TPS voltage.

 

how do i do that?

 

First, I am presuming that this is regarding the '88 IROC in your signature, and although it has a " '91 350", it still uses the '88 ECM and wiring.

More often that not, a DTC 33 is caused or contributed to by a TPS voltage that is too high for a given throttle angle. This can occur if the TPS has been installed or adjusted incorrectly, or especially if the throttle stop screw has been inadvertently adjusted. Since the ECM is supposed to control the idle RPM through the IAC, there should seldom be a need to adjust the throttle stop.

Using a DVM, you can back-probe the 'A' and 'B' terminals (black and blue wires) of the TPS connector with the ignition turned ON. The voltage reading should be less than 0.060VDC. Ideally, it should be at 0.54VDC.

Another thing that can cause the error on your installation is operating a 350 wiht an ECM program written for a 305 TPI. The ECM expects less intake air to flow at any given RPM and/or throttle angle. Any hints about the engine/ECM/PROM installation?

 

so i probed the mass airflow sensor in the back (being the green wire and the black one) of the connection and i got around 2.5 volts both when the car is "on" and when it is idling. is that normal? if its not then what do i do?

 

i've been reading alot about code 33 being wut i have due to a messed up tps. im gettin 2.5 volts at the maf at idle so im going to adjust the tps. now how do i do that and am i reading the right voltage? do i need to probe the tps or just from the maf?

 

I believe that there is a tech article on this issue (TPS adjustment),,, it really does not have anything to do with the MAF sensor. At idle the TPS voltage should be around 0.54V factory (check the article for the correct voltage). For better throotle response, you can try 0.60V to 0.64V... I think that I'm at 0.62V now.

 

Idling, the MAF analog output signal should be around 0.800-0.950 VDC.

A reading of 2.5VDC means one of a few possibilities:

1. The engine is "idling" at about 5,000 RPM, drawing in about 128 g/S of intake air (not likely);

2. The MAF burnoff relay/function is faulty, and the burnoff lead to the MAF is inadvertently energized. You can eliminate that possibility by reading voltage at the dark blue wire at the MAF with the engine running. There should be nearly 0 volts. Anything more is a problem.

3. More likely, it means that the installed MAF is the FM type and not the analog type. The FM MAF sensor outputs a 5V P-P square wave signal at varying frequencies. The duty cycle of the square wave is designed to be 50%, so most meters will average that signal on a DC voltage scale to 2.5VDC - just what you are reading.

Read the part number on the MAF and report back. I'm curious. Very curious.

 

I just tried to track down your problem history.

This may be the answer:

https://www.thirdgen.org/techbb2/sho...hreadid=317351

I can answer. They are NOT the same. The V-6 MAFs are the aforementioned FM type. The V-8 MAF in 1985 was the FM type. From 1986-89, the V-8s used the analog (Bosch) MAF . If you installed a V-6 MAF on a V-8 ECM and system, you've found the problem.

 

no its still a bosche in there right now. i havn't checke the burn off relay yet so i'll probe it tomorrow. see if its 0 volts at the blue wire. if its 0 volts then im going to just replace the mass airflow sensor. do u think that would be a good course of action?

 

i would adjust the TPS as before recommended and if i replaced anything, it would be the MAF power and burn-off relays. i used to have te same problem. like vader, i doubt that it is the MAF sensor.

 

Did you find the part number on the MAF yet? I'm guessing that it isn't the same as this one:

 

0280213009

10055877

it looks exactly the same, those are the numbers on the bottom of the maf.

 

ok, then maybe it is the maf sensor. i just checked my factory one and it matches the one vader is showing.




i just went and checked a parts sight and they list those cast numbers as a borg warner new one.

 

I am having the same problem. My car continues to show a Code 33. I just recently got the Holley Stealth Ram Intake installed and i got a code 33. So i replaced the MAF Sensor, MAF Sensor Relay, MAF Sensor Burn-off relay, TPS (and had it set), IAC. I am still getting a code 33. The check engine light will come on then go off about 5-10 seconds later. I have had nothing but problems with my car since i got the HSR installed. I have no idea if the MAF is the problem or if its something else.

 

That number should be a valid analog MAF. If you have no voltage at the burnoff terminal and are reading 2.5VDC at the analog output (with a reliable meter) the MAF is toast.

 

I have a 1986 camaro Z-28 with a 350 tuned port(really not sure what car the engine came from), I keep getting the 34 code so I took the maf out and ran the part numbers(0280213009), also the connector is busted on the maf sensor, the only part that comes up is for bosch.
Every maf sensor i have looked at for my car has a three pin connector but the bosch that is on it and the harness in the car is five pin.