Help Idle Surge and Voltage problems

[95WhtStang]

A few weeks ago I started having surging and stuttering problems with my 95GT after doing a tune up. Well I took it to a Mustang shop to get looked at and they told me the timing was set wrong so the reset it to 11 degrees and they adjusted the TPS so it was within spec and they said the MAF and IAC were fine.

The stuttering problem went away, but now I'm having an idle surge like I did before and the voltage seems low at idle. When I turn on the headlights and fogs and use stuff like the window switches and hold them down the voltage drops down low and the lights dim, and it gets even worse when I turn on my radio and sound system on. Also when I turn the A/C on the idle will surge up and down between 50 and 100RPMs.

So right now I think I have a voltage issue somewhere or something is draining my system. The battery is new and only a couple of weeks old and I had the alternator checked twice on the car and off and it tested fine.

Right now the car is idling around 700 or 750 so I think i may need to bump it up a little bit to keep up with the voltage draw and I was wondering what are some voltage test I could do on the car with a multimeter to make sure everything checks out?

 

[cotchnobra]

Is this a 5 speed car or automatic. If it is a 5 speed usually idle is set around 8-900 rpm. if you still have problems try cleaning or replacing the idle air control valve (IAC). also the TPS sensor should be set at .98 volts when at idle. also for the voltage issue if you have underdrive pullies that will deffinetly cause what you are describing. I've had many 5.0 cars and underdrives or not they all dimmed the headlights with heater or wipers on. both of them on dimmed it even more. as long as your batter gets charged and the lights brighten up when you give it a little gas you should be fine.