cosmick

So after way too many tuning sessions, here's the end result: at 4500' elevation, I have a steady 16.5" of idle vacuum at a fast idle, after having to drill through the idle mixture screw holes to make the adjustment functional. I didn't want to admit to that, but Cliff Ruggles himself has convinced me that that wasn't cheating. I ended up at 38* total mechanical advance, and now I'm ready to to a MPG and dragstrip day as soon as funds permit.
Before I resorted to drilling idle passages, I rebuilt my QJ, I replaced all the top-end gaskets with new FelPros and used a new can of Edelbrock's Gasket-cinch stuff. Well, part of the can. I plugged off all the vacuum ports except one manifold vacuum directly to the distributor vacuum canister, a 6" length of new hose.
Once I got it to idle, I tried things one at a time. First the PCV, no problem. Then the power brakes, no problem, both of those take manifold vacuum off the base of the QJ.
Then I did the EGR to ported vacuum through a thermal vacuum switch. This way it can't open when the engine is cold, and it can't open at idle or at WOT.
Driveability is good, low-end torque isn't as strong as my old L69 with Comp 12-388-4, but the upper midrange is stronger. I think it wants L31 heads and headers, but I'm swapping a Vortec 454 instead. This will go into my '87 S-10 once the 7400 is ready.