Thread: 78 Trans Am getting some love

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I think we're getting somewhere now. I finally had a chance to go down the list, compression is 150-155 straight across the board, I did not do the oil squirt in the cylinders though. I figured if their that close there shouldn't be any surprises inside. I reset the valves and I was pretty sure they were going to be too tight vs how you wanted me to set them and I was right. I was taught to go 1 turn after 0 lash and that is how they were, so I reset them to 1/4. I checked the fuel pressure and it was at 6 which Holley said is good. The vacuum did seem to pick up to 10 but no real change. I decided to buy an AFR gauge, put it in and It read about 15 at an idle which is stupid rich. I messed with the timing, vacuum advance, and turned in the idle mixture screws and nothing changed, it and it was running like it was before. I shut it off and stared at it a bit and did some abstract thinking and thought gaining vacuum is my #1 goal right now so I started it up and turned the idle mixture screws out 1/2 a turn further than before and BAM, it purrs like a kitten, my exhaust lope is gone, the stink is gone and it doesn't diesel when shutting it off. Vacuum is now a steady 14 and the AFR is nice at around 12. Before I get beat up on not adjusting them right the first time I did it like I always do, turn them in till you hear a change and then back it out 1/2 a turn, it always worked before. So when it was all said and done I needed to give it more fuel to lean it out. Thanks so much for not letting me rip my motor apart right away at the first sign of trouble! Now it should be a breeze to tune the rest of this carb with the AFR guage!