Every so often, my fiero decides not to start. 4 cylinder (Iron Duke). It doesn't crank or turnover at all. Tachometer doesn't move either. It's happened before where I waited 5 or so minutes after it wouldn't start and it started up then, but now it won't start up at all without a jump. The temp gauge swings all the way to the right, and the lights dim. I took it in and they said the starter, alternator, and battery are all fine, but that it might be bad wiring. Has anyone else had this problem?
Corrosion often sets in between the cable and the terminal on the starter. Try disconnecting the large positive cable to the starter, cleaning the post on the starter as well as the eyelet on the cable, and reconnecting it. Just remember to disconnect the battery before you do this because the large cable is live and will carry several hundred amps if it touches the chassis anywhere.
The other area that frequently causes this is at the battery terminals. Side post terminals are notorious for making a bad connection and allowing corrosion to settle between the eyelets and the terminals.
I was having a problem similar. Sometimes I would just get a click when I would go to start.... usually after that would happen, the next day my battery would be low (or dead at times.)
When the starter would engage, it would start just fine. It was fairly random. I haven't had a problem since replacing my starter.
I'm not a huge car guy, but I'm trying my best to learn now with the Fiero. When I took it in they said the starter was fine, is the solenoid different? Also, how easy is checking the ground cable, etc?
The problem that I had, was since the solenoid would usually work, I think that it would have passed their test.... it's those times that it didn't spin the start you can't really test for.
On the times that yours doesn't start, do you hear anything when you turn the key? A click? anything?
No clicks, but sometimes a very quiet almost... whirring sound from the back right?
That could be the fuel pump....that makes a noise for a couple of seconds when you first turn the key on. Also that may a noise the starter makes with the little power it is getting. I think I am agreeing with the gang here suggesting the the battery cables at both ends of each. I went out to start my 87 GT one day and I turned the key and got a half a crank and then nothing. I checked the battery terminals with my volt meter and got zip. I disco'd the battery for replacement and decided to check voltage on the battery itself ....zip ....that is until I put the probe directly inside the terminals (where the screw/bolt screws into) and got 12v! Again when I put the meter on the mating surface I got nothing. I looked at the cable's mating surface and the battery's and you could see a bunch of corrosion (not the foamy blue stuff you sometimes see, but stuff the looked a lot like rust). I took a dremmel tool with a wire wheel attachment and went after those mating surfaces and voila! When I reconnected the battery it started instantly (and cranked briskly too). That type of thing is common and makes a huge difference and likely wouldn't show up on a test a lot of the time.
[This message has been edited by 92wastheyear (edited 09-02-2013).]