idle low throttle body bad?
 

my car idles low when its fully warmed.. and the voltage level is also low when i have my head lights on and my sound system bumpin. but when i turn off my lights the voltage leve goes back up... got the car diagnostics check up .. and the guy who checked it for me told me that the " throttle body was bad " needed a new or rebuilt one.... so any suggestions? or anything i can do ? or do i have to really get a new or rebuilt throttle body.. thanks in advance...

Who is this idiot who told you that?
The throttle body cannot go bad unless you throw a brick at it or shoot it with a .45.

You sure he didn't say throttle *position sensor*???


-Ted

Check your Crank Angle Sensor (CAS). It should automaticly compensate for a higher power demand from the alternator because the lights are on by increasing the air flow to mantain a constant idle.

Does the idle drop when you push the break in or turn the AC on?

is there a site where i can go to so i can know where to check the CAS? like a how to for dummies? ... i'm basically pretty new to the rex family... but yea the idle drops to about 300 rpm when i press on the brake... but when i release it.. it comes back up to about 500-600... it never idles at about 700-800 when car is fully warmed up .. only when its cold.. it chills at about 800-900... actually everything dims off when i press on the brakes... so i dont know whats going on...

yea the shop is in san gabriel valley area... but yea he did tell me the throttle body was bad.. and that he can find me a rebuilt one... he found one.. and told me it would be 180 for it.. without installation... so i'm kinda in the hole... need to get this fixed... =(

The idle you described is normal for a stock FC. You said you had a sound system installed, that is your problem. Your 20 year old alternator and battery cables cannot handle the power demands of your sound system. Before you do anything, get your alternator rebuilt and replace your battery cables with high quality welding cable. Replacing your battery and buying a capacitor for your system would be advisable as well. Tearing into your CAS would be a foolish thing to do without knowing the condition of these most basic of basics.

Edit: Almost forgot, you can also upgrade your alternator to a FD unit. They are better suited to a higher power demand (100 amps compared to 60) such as yours.

Here is a writeup.

I'd look at https://www.rx7club.com/2nd-gen-archive-72/faq-idle-problems-334730/ for general idle problems.

And I think http://rx7.subbuteoclub.com/idlecontrol.shtml should go into a bit more detail on it.

I'm having the same problem actually, I'll let you know if I find anything else. Does the idle always bounce or just sometimes bounce and sometimes its fine?

cool... thanks guys.. those links are full of information... just reading through them... till i get paid this friday... so i can get that fd alternator... and other stuff.. thanks again


-david

sorry didn't read all of the responses but that one thng sounds like your charging system, more specifically your alternator, it is prolly dying, as it gets worse you'll start ahving more problems, like radio shutting off at night and then gausges will get dim , and then car will stall.....that was my experience to a tee with my '88 GXL and my 1000watt system.....

yea everything has been dimming off... and the car did stall just the other day.. and my system did turn off on me while driving to work... but my fd alt is on its way...