Hi I am stuck on that code 34 maf sensor.I was wondering ,my voltage gauge is bouncing between a little more than half to 3/4 (im assuming 12v to 16 v) in sync with my idling when bonny decides to do its rpm dance 700rpm to 1300 rpms .It doesnt do this all the time and rarely stalls but does on occasion.Could a faulty alternator give a maf code and do this, or could the problem with idle make the volt gauge move around.No vacuum leaks, changed maf sensor , cleaned idle airand TB cleaned EGR. Thinking Cat,02 sensor,tps, I also read something about coolant temp sensor is this possible.Please help,thankyou.

a bouncing idle is usually caused by a bad IAC. you cleaned it right? Maybe its better to replace it?

The alternator volts should definitly not bounce arounds, given the rpm of the engine. Your voltage regulator must be bad, time for a rebuild. Also, check your connections before proceeding. Do the lights flicker with the bouncing alt? I remember when mine did that, just paid 50 dollars for a junkyard alternator. Its better to get a rebuild, with a 2 year warranty.

So you think I should change the IAC,and alternator(is this what you mean by voltage regulator)Also lights do not flicker.

Ive got rid of bouncing idle I guess I had to wait for ecm to adjust to new maf.Im still not sure about alternator whether to change it or not,I think it reads high and sometimes moves around in voltage even when I put signal light on it bounces with signal.Can you direct me how to test with multi meter Im not sure which setting on meter to use or where to test.thanks

Mine does the same thing. The voltage on the dash reads quite high, but goes down significantly when I turn stuff on. Test your voltage at the battery posts.

voltage reads about 12.5 when car not running and about 13.80 at idle,5 min later at idle it is about 13.60

One other thing ,when car is idling I can hear something click and then click again . 20sec later click on and maybe off dont know sounded like it came from alternator or coil pack couldnt pinpoint it,does antone know .thanks

Quite the newb I am ,it is my A/C compressor clicking on and off can anyone help me troubleshoot.Imagine it is something electrical.It does this on defrost and only seems to be at idle.

A/C compressor is cycling on and off usually the reason is due to Low A/C freon in the system.

Your voltage readings are perfect. 13.5-14.1v at idle are completely normal.

My voltage meter bounces all the time- It was really bad before I replaced most of the wiring, but it still moves around a lot. My 89 SSE moved all over the place- especially when the AC was on. The 91'* AC is disconnected right now, and the voltage is good- also with heater and rear defrost on. I do still notice a dip when at a light, rear def. on, and turnsignal. But these are all high draw items. I haven't had it flicking around with RPMs though. I would have to agree with Tim'* Buick on this one- try a new alternator. After having two of these cars myself they chew through alternators. The 91 is on its 4th in almost 5 years and I have a new alternator in the trunk- just in case. takes only 10 min to change it, and saves you a tow. It is brand new- and the one that it uses now is from the yard. $30 for used, and $220 for new.
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