Q: My 1969 Chevy Camaro has a brand new 377 cubic inch small block, a Turbo 350 transmission (4,000 rpm stall), a 12-bolt rear-end with 4.11 gears, an MSD 6AL ignition box, Mallory Unilite distributor, Powermaster alternator, Moroso electric water pump, Holley electric fuel pump, and an electric fan.
I watched the 377 dyno at 515 horsepower at over 7,300 rpm. Once I put the engine in the car, a problem occurred.
In first and second gears, the engine starts to miss at 6,100 rpm. In third, the engine keeps climbing up over 6,500 rpm before I cross the finish line. The car still turns 11.30s at 116 mph while shifting at 6,000 rpm, but I’m afraid I’ll hurt the engine if I don’t fix the problem.
To try and fix the problem, I’ve completely rewired the car, running the fan and water pump through relays. I’ve also installed a fuel cell and 1/2–inch aluminum fuel line. Neither of these fixes has worked. I’m thinking about a new fuel pressure gauge and an MSD billet distributor, but before I spend more money, I was hoping you could help me out.
A: That’s a tricky one, so we’re going to have to put on our detective hats.
Let’s back up for a second.
What’s different between the engine on the dyno and the engine in your car?
If something is different (distributor, carb, fuel pump, etc.), take a look at that first.
If everything is the same, you should check your coil voltage (it needs to be 12 volts or more). With a 1/2-inch fuel line and the kind of power you’re making, gas can stand still in the line.
What kind of fuel pressure do you have at 6,100 rpm? Is it running lean? To check, rev up to 6,100 rpm, turn off the car, and pull a spark plug.
You’re definitely on the right track—it’s either fuel or spark. So, check these things out before you throw any more money at the problem.