My car will start up and run for a while, but then the rpms will start to drop and the idle gets rough and the engine eventually dies. i pulled a code 34 can someone give me a little help with this. If it matters I have an 89 2.8 Firebird. thanks

 

The code 34 in your model, I'm sorry to say, is for the MAF sensor. It is either a bad MAF, bad electrical connection or a defective ECM. Mine is a speed-density car, so I don't know much about diagnosing MAF problems and maybe someone can help more. You'll probably end up having to spring for a new MAF. Hope this helps.

 

Clean the MAF with some carb cleaner, and clean all the wires and relays and make sure they have good connections. This happens to me every once in a while, cleaning has always fixed it. You might want to check your TPS and IAC while you're at it.

 

Definitely try what rezinn said first, 'cause those suckers are expensive.

 

Thanks guys, I'll try it tomorrow. i hope i dont need a new one.

 

89,

Another thing that can cause a '34' (MAF sensor low flow) is a leak in the intake ductwork between the throttle body and the MAF, excessive vacuum leaks (including a brake booster and incorrect PCV valve, gasket leaks at the throttle body or intake, and a TPS sensor that is adjusted too high.

If replacing the MAF power relay and checking/cleaning the electrical connections doesn't solve the problem, try those possibilities.

Another thing that can cause hte problem is a broken hot wire sensor in the MAF itself. One way to test for this is to tap the MAF housing while the engine is idling with no SES light on. If the idle stumbles adn the SES light sets when you tap th e housing, your MAF may be toast. There is no easy way to replace the hot wire element. I've tried. I got it to work but it reads incorrectly due to the minute difference in the length of the platinum wire I could install. And platinum 41 gauge wire is not cheap, either. If your MAF is dead, check Wells Manufacturing. They offer a thick-film sensor MAF that has no hot wire to break.

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i might also add that carb cleaner is for carbs....you should use throttle body cleaner....carb cleaner can mess up the seals in a FI

 

A good way to figure out if it is the MAF itself, or a bad wire or connection is to perform the following:
1. Clear any codes stored in the computer.
2. Start the car and see if it sets the "34".
3. If it does, shut it off, and clear the codes again.
4. Disconnect the 3-wire connector from the MAF.
5. Start the car again, and see if it throws a "33" or "34"

If you get a code 33, then the MAF is in need of replacement (or maybe just cleaning as stated above). If it still gives you a code 34, then the sensor is fine, and you have a loose connection somewhere, or an ECM problem. I just went through this ordeal last week with mine, and I wish I would have known about trying to clean the MAF first! I replaced it and the car runs fine, and is even quicker now that I shaved that weight out of my wallet!! Ouch Hope this helps.

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'87 IROC Z28
TPI 305
5-speed
3 1/2" exhaust w/ Flowmaster
Clarion, Kenwood, Eclipse, Polk, MTX, Autotek 1600 watt stereo system
Grant wheel