Hi everyone, I'm hoping someone can put me
on the right track. I have a newly rebuilt engine
that I've put about 3k miles on. It's the 350 5.7L
TBI, it is bored .30 over and I installed vortec heads
with a vortec to TBI intake. Truck has run like a new one
through break in, I've been pleased with it. So here's my
problem. I checked timing today, disconnected the little esc
or whatchamacallit wire, turned the distributor to get O on
the dial, tightened dizzy, shut truck off. Disconnected battery,
reconnected wire, waited an hour, reconnected battery. Started truck and
its showing app 12 degrees before. I disconnected wire and it shows
O, went through procedure again and obtained same results.
I've read that setting base timing to O allows the computer a base to start
from and disconnecting battery allows it to recognize the new setting. What
would be causing mine to continue being so far off. I've run three of these
5.7 TBIs over the years and never had one do this when setting timing.
Any help would be greatly appreciated.

 

That's exactly what it should do.

No need to disconnect the battery.

Allan

 

It's not running the same, power is off. This engine had no
hesitation when stepping on the pedal. Everything on the engine
is new. Something has to be wrong.