I have an code 33 now what to do its on an 85 so I hope it isn't the burn off ant sugestions?

 

Your MAF is probably bad...the burn-off code for an 85 is a Code 36....I think the code 33 is low flow...check that you don't have a hole in your accordian tube running from the airbox....check it good in all the folds, as these have a habit of developing a leak....

Cheers,
Michael

 

Your MAF has a burn-off module behind the RH side of the I/P that both provides power to the MAF and provides the burn-off power when called for.

If you send me an email (jgkov@msn.com) I'll photograph the trouble shooting pages from my '85 GM Shop Manual and return the pics to you.

 

Code 33= manifold air pressure (high)
Code 34= manifold air pressure (low).

yes check both Maf and Burn off midule whic located beside main ECM, its a rectangle shape small box with a pigtail wires.

 

Sami, these are not MAP codes, they are only that for the MAP cars.

Whatever trouble guide youre quoting is wrong if its for 85s.

 

Vader86: u r right, avtually i was looking into my laptop Winaldl S/W that says 34= map low but in reality its MAF related, my bad iam sorry.

Sorry here i copied this :

CODE 33

Trouble Code 33 indicates that the Mass Air Flow (MAF) sensor is reporting more air is entering the engine than makes sense based on RPM and TPS. The MAF sensor produces a frequency output; around 30 Hz at idle to 150 Hz under acceleration. The frequency varies proportionally to airflow. The ECM monitors the frequency and thus determines airflow into the engine. Typical idle MAF is 5 to 7 grams per second.

The conditions for setting this code are:

no Code 21 or 22 (TPS Error) present, and
the air flow reported is > 40 grams per second, and
TPS indicates < 10% throttle position, and
the engine speed is 1400 RPM or less, and
the above conditions exist for over 5 seconds.



Typical causes for this code include:

1) Faulty MAF-to-ECM connection
2) Exceedingly noisy spark plug wires
3) Poor routing of MAF harness (i.e. near coil packs)
4) Maladjusted TPS sensor
5) Defective MAF sensor
6) Defective ECM


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CODE 34

Trouble Code 34 indicates that the Mass Air Flow (MAF) sensor is reporting less air is entering the engine than makes sense based on RPM and TPS. The MAF sensor produces a frequency output; around 30 Hz at idle to 150 Hz under acceleration. The frequency varies proportionally to airflow. The ECM monitors the frequency and thus determines airflow into the engine. Typical idle MAF is 5 to 7 grams per second.

The conditions for setting this code are:

no Code 21 or 22 (TPS Error) present, and
the air flow reported is < 4 grams per second, and
TPS indicates 10% or more throttle position, and
the engine speed is 1800 RPM or higher, and
the above conditions exist for over 5 seconds.



Typical causes for this code include:

1) Faulty air ducting to or from MAF sensor
2) Faulty ECM-to-MAF connections
3) Poor routing of MAF harness (i.e. near coil packs)
4) Maladjusted TPS sensor
5) Defective MAF sensor
6) Defective ECM

 

Just some additional info for the codes for the 85.
http://www.corvettedoctor.com/1985_91_DTC_Codes.html

Code #12: Normal No Codes.
Code #13: Open Oxygen Sensor Circuit.
Code #14: Coolant Sensor Circuit Low.
Code #15: Coolant Sensor Circuit High.
Code #21: Throttle Position Sensor High.
Code #22: Throttle Position Sensor Low.
Code #23: Manifold Air Temperature Circuit High.
Code #24: Vehicle Speed Sensor.
Code #25: Manifold Air Temperature Circuit Low.
Code #32: EGR System Failure.
Code #33: Mass Air Flow Sensor High.
Code #34: Mass Air Flow Sensor Low.
Code #36: Mas Air Flow Sensor Burn-Off Function Fault.
Code #41: Cylinder Select Error.
Code #42: Electronic Spark Timing.
Code #43: Electronic Spark Control.
Code #44: Lean Exhaust indication.
Code #45: Rich Exhaust Indication.
Code #46: Vehicle Anti Theft Fault.
Code #51: Faulty Mem-Cal.
Code #52: Fuel Calpak Missing.
Code #52: (1990-91 Corvette Only): Engine Oil Temperature Sensor Low.
Code #53: System Over Voltage.
Code #54: Fuel Pump Circuit Low Voltage.
Code #55: Defective ECM.
Code #62: Engine Oil Temperature Sensor Circuit High.

 

I want to thank yall for the feed back. It turns out that it is the mass air flow sensor look like it got some water in it that hurts the old pocket book.

 

Give a call to Contemporary Corvette (link on my site) or one of the other used Vette yards; they may be able to supply a good used MAF at a fraction of the cost of new.