when I fist start car for the day engine light comes on. After car is warmed up and started later light is off. Then as car reaches proper operating temp engine light comes back on and I lose idle, irratic shifting,over all performance. The error code from the ALDL shows code34 maf sensor.
Does anyone have any ideas of what else could cause this error, and how to test the maf sensor. I can't find any visaul problems.

 

The 1985 TPI system is a bit more difficult to diagnose due to the digital (FM) output signal of the MAF. The common problems which can cause the error code are:

• Air leaks into the intake tract that aren't measured by the MAF;
• Poor connections between the MAF, the power source, and ECM;
• Incorrect data from other engine sensors, like the TPS.

Any vacuum leaks, intake duct leaks between the MAF and throttle body, CCV tube or PCV leaks (including a breather type oil filler cap), and an altered/descreened MAF sensor can affect the accuracy of the MAF signal. Any marginal relay contacts or connections can degrade the MAF signal. Make sure the TPS voltage is set correctly. The ECM relies upon the TPS and engine RPM data to determine the allowable range of MAF signals.

 

Would this apply to the 87 as well? Having code33/34 issue.