i was riding to work today, and the tach signal started jumpin pretty bad i kept drivin it finally stopped moving. then my radio started cutting on and off.
the car got weaker so i babied it the rest of the way tow ork. about 3/4 there, the car would not hold an idle (it wont idle without correction from my VAFC, and it died) so i had to hold the revs at like3k to keep from stalling out. then right in front of work the car died and the battery light came on. i had to puch it the rest of the way and it wont even turn over now. it started spiting random CEL's out, code 22,5,15. i know these things arent issues becasue ive driven 15,000 miles with those aprts in the car. i think the alternator cause my electrical system to wig. anyobody else have any insight?

 

I would think if it was your alternator, the battery light should have been coming on before the car died.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Reminiz &raquo;</TD></TR><TR><TD CLASS="quote">I would think if it was your alternator, the battery light should have been coming on before the car died.</TD></TR></TABLE>

I agree. It sounds like a bad ground or connection somewhere maybe?

 

ill go check it out, but it was realy weired, any othe rinsight?

 

i just chcked all the grounds, they are all tight. i tried to start the car and then it started, but the battery is worn down it was tuning over real slow. i specifically looked at the valvecover to chassis ground, and the ground near the thermostat. i also checked the cable on the alternator and it was tight. the battery connections were tight too.... anybody with some insight help plz

TIA

 

it is the alternator, same thing happened to me about 3 weeks ago. but now the tack is starting to jump again, so it could be a grounding problem or something causing the alternator to burn up

 

I agree with Brownjd.

I was having the tach jumping issue myself. I swapped alternators with a known good one, and the problems went away. I ended up replacing the ignitor, cap and rotor on my previous unit.

No problems since. (it's been 3 months now) Hope that helps!

 

i DO have a spare ignitor/coil laying around last time my tach went haywire on my b16 del sol it was the ignitor wire coming loose. so right now i have half the people saying alternator, and the other half saying ground issue ;lol. im gonna double check my ground again after lunch. any other places i shuld be looking?

BTW- i assume alternator cause this motor is seeing 10,000rpm daily and its still the one that came with the motor (90 b16)

 

an alternator can cause the tach to jump? Also, there's a bunch of places around here that will check alternators for free or a small fee...try to find one of those to eliminate a choice or not.

 

new info. i checked the battery voltage before starting the car, it was at 10 volts. i then started the car and rechecked the voltage, it was showing same voltage. since my previous experience in battery testing leads me to believe the alternator should be putting from 13-14 volts to the battery when running, i believe the alternator is in fact bad

 

JACKPOT-
The alternator should be putting out 12.7 at all times except when charging and then it goes up to 14.1-14.4. The ELD in the Main fuse box controls the regulator so get the alternator tested on the car. A shorted cell in the battery can also cause wheat you describe.

 

a battery should read at least 12...usually around 12.4. can go all the way up to 14, but if it's sub 12volts, that's a no no.

you can have the alternator checked for free usually. at least that's how it works at my job. i just take the alternator and put it on this skewer thing on a machine and connect a positive and negative to it and check the volts right there...works with starters too.

 

I dunno if this helps, but I had to replace my alternator's power wire b/c it went bad...