'hiccup' at 3000 rpm only with vacuum advance connected

onovakind67 · Post by **onovakind67** » Fri Aug 15, 2014 5:49 pm

Your dynamic compression will be higher with the shorter cam, possibly creating some timing issues.

CBradio · Post by **CBradio** » Sat Aug 23, 2014 9:01 pm

so I think my car runs a tad better with 89 over 93 gas in it,
but I haven't run it up a hill at 70 mph so we'll see.

...Thanks to the help, I think my car is finally timed right, now that I understand how the distributor works.

I just wanted to thank everybody for their time!

CBradio · Post by **CBradio** » Fri Sep 19, 2014 5:24 pm

I hate to beat a dead horse, but I have a question related to pinging:

Does it sound similar to lifter noise?

I have, what I think is lifter noise but maybe pinging, under load at 1800-2200 rpm, especially if my car is not at operating temp or has not been at operating temp for a bit.

I always assume its valve noise, but maybe I am mistaken, which is a scary thought. In any event, this seems the only type of sound I'm able to get out of my engine no matter how much I advance it. I assume its valve noise only because I get it when the engine is cold or "coldish" .

I can really also only hear it when I roll the windows up mostly.

CBradio · Post by **CBradio** » Wed Sep 24, 2014 4:50 pm

Just wanted to follow up here.

I am pretty sure now, after messing with timing a bunch and octanes again for the last few days, that if I add too much advance I get light pinging at 1800-2200 rpm. I retarded the timing a bit and it seems to make it go away.
Sounds kind of like a tractor like noise from the top of my valve cover.

I was confusing this noise for a noisy valve train the whole time!

I think I have been light pinking around town like nobody's business.
I think at the same time my car feels peppier with the added advance.

I'm thinking I need a b35 motronic upgrade sooner or later.