Odd Problem

Well, I changed the gaskets last night and as always I did not use the end gaskets, just rtv.

I also checked the pcv and the brake booster check valve. Nada. I tried spraying carb cleaner n all vacuum areas. No obvious fluctuations in rpms. There is about 11 hg of vacuum at 750 rpm idle in neutral and it is rough, but not missing. When I put it in drive, it drops to 500 rpm and about 6 hg. The vacuum does come up with revs above 1000 rpm, upwards of 20 hg. The cam is a Comp XE 268 with 8:5:1 compression.

When working the brake pedal, there is ever so slight rpm fluctuation.

What I did notice was slight suction from the tail pipes and smoothing of the idle when I cover them up. Again remember, there is no missing, just a hesitation when bringing the revs up from idle in drive. No pinging, no popping or backfiring through exhaust or carb. No valvetrain noise as well. Great oil pressure and the valvetrain is tight when checked.

For the record, the TC has 4000 miles on it and is a modified stock size converter with a 2800 stall rating.