Hiccups of my tachometer
My name is Adrian, and I bought a 1976, L82 Vette 6 months ago.
Overall I am really happy with my new toy, love the way it drives and love the way it looks.
The only issue I had with her since the beginning, is when I push the throttle full down, at 4500Rpm and above she got serious hiccups, but I thought I could live with that as I am not planning on racing it :-)
I am currently encountering a problem, let me explain you the thing:
Few weeks ago, in a mechanic shop after having upgraded all the braking system, the guy told me that the timing was a bit off. We adjusted it at the time by ear. The car was running fine, was drinking a bit more than usual but was ok. I realized in the following weeks that it was really really hard for me to start the car when she was hot.
So I bought a timing light and this morning went ahead and tried to improve my timing. First of all at the start the timing was off by 35-40 degrees anticlock wise. I did reduce it to the 12 degrees recommended in the specs of the car, and when I reconnected the vacuum hose the timing did move. So far in my head this morning I was pretty happy.
I took her for a test drive and I realized that my idle is not stable: the tach jumps from 1000 to 1400; and below 3000 the tach vibrates ±200 RPM. Above 3000 rpm no more weird movement of the needle.
Anybody got any suggestions ?
Thanks a lot.