gimpala63n70

iTrader: (4)

Hey everyone i have a 93 z28 with 80k miles, shift kit, 4:10s, SLP exhaust, Cold air intake. On the way home from the track saturday my speedo stopped working all the sudden and the car started running all crappy, bogging, stalling, not shifting right, idling high...It ran perfect all day, nice consistant 13.8s at the track and then on the way home it all happened at once..What could this be, the check engine light came on but for some reason my car wont let the scanner read it. thanks for any help

98Camarod

iTrader: (43)

I've seen on other cars that if the scanner cannot communicate with the computer that the computer was bad. These cars also would not run. So this probably is not your problem.

4u 2 nv

iTrader: (29)

opti spark?

gimpala63n70

iTrader: (4)

But why would the speedo go out then all this happens? Im thinking vehicle speed sensor, im going to try and change it ill update u guys. Thanks

SSuzuki

I've seen some stuff like that happen from a alternator but I dont think it would affect the speedo.

68Goatboy

iTrader: (1)

on the old car i used to drive, i could always tell when the battery was going to die because all the guages would shut off or start dancing around like mad. it still drove fine but if i shut it off it wouldnt start again without a jump. but this was in a 1981 mercedes. less stuff was computer controlled back then, maybe that could be part of the problem?

1WICKDZ

iTrader: (2)

+1 on alternator

Starz T/A 17

iTrader: (6)

My 2 guesses are either the Alternator shorting the car on power causing it to act up or the Computer, my dad had a GM mini van with a 3800 series engine in it acted EXACTLY what you desribed running like crap, shifting sloppy, exc and it turned out it was the computer.

Thub

Bad connection somewhere? Maybe a ground came loose, giving the computer intermittent power? Something cheaper than an ALT or computer to at least check for.

the_merv

iTrader: (88)

Mine did the same thing before the Ignition Switch **** out.

razorclaw99

iTrader: (7)

'Trust'

iTrader: (24)

Did your speedo completely stop working, or was it reading very weird (say you accelerated to about 50, it would show it at 30). It could be the VSS, it would be the reason for your shifting issues, the computer would think the car was going to slow to meet RPM/Speed requirements to shift. The high idle and stalling, maybe.

gimpala63n70

iTrader: (4)

Alright guys one more question..
Im driving the other day, shut the car off and get out. Go back 5 mins later and it fires and shuts off, then will not start for anything in the world, i had fuel pressure, ihad to getit towed home. Next day i curiously try and start it, it Fires right up so i say whatever and keep driving, next thing i no it does it again..Now its missing really bad, still no speedo, barley starts, hesitates really badly when getting the revvs up while driving and even sitting there revving it..Another thing is i havea check engine light, so i go to read it and i tried 2 differnent snap on machines and they will not communicate with the car so who knows what code i have. Well guys help me out please beforei blow to much on the optispark, thats fine if i have to but id like to know its gonna work..Whats the ignition thing people are telling me about, about how much is it etc...thank you!