OK....74 with 302, Holley 4160, List 6919 (idle mixture air control needles), 600cfm, new distro for factory Druaspark, Blaster coil, new ignition module, 83-85 Mustang GT aluminum intake with Edelbrock solid aluminum EGR block off spacer plate and heat shield, new PCV valve, rebuilt C4 with low miles, new vacuum modulator, Trans Go shift kit per tech article, chebby power disk conversion, timing at around 12 deg, idle set at about 600rpm, vacuum at idle is around 15-16 inches, 5.0HO timing chain, heads marked as 1978 vintage, Hooker comp headers with dual exhaust 2.25".
It idles really nice but runs terrible and stalls some when I put it into gear. Once I give it a little gas while in gear, it will run better but still just a bit rough. C4 shifting not feeling quite right either. Did the usual vacuum checks with carb spray, unhooked the brake power booster and line to the trans vacuum regulator no effects. I don't know what cam is in it but the heads seem to be changed to 1978 with no holes for the air injection. I didn't rebuild the engine so don't know. I even swapped in a good condition rebuilt Holley both were List 6919...the old one had loose throttle shaft, "new" one is tight, swapped in the Truck Avenger vent. The driver's side idle mixture has no effect even though I shot carb spray into hole shooting a small geyser up through bleed. If I push in electric choke manually when warm, vacuum goes up to nearly 20 inches.
Am I missing something? Really acts like a vacuum leak. Before I pull intake off and replace gaskets or even swap in an old cast iron 4V intake I have laying around, I plan to change the fuel filter, check the volts to the coil and check the fuel pressure. Iv'e worked on Holleys, Ford 302s and 5.0Ls since I was 15...53 now and this one is stumping me.
Thoughts? Ideas? Please share experiences!
Thanks!
Mike
It idles really nice but runs terrible and stalls some when I put it into gear. Once I give it a little gas while in gear, it will run better but still just a bit rough. C4 shifting not feeling quite right either. Did the usual vacuum checks with carb spray, unhooked the brake power booster and line to the trans vacuum regulator no effects. I don't know what cam is in it but the heads seem to be changed to 1978 with no holes for the air injection. I didn't rebuild the engine so don't know. I even swapped in a good condition rebuilt Holley both were List 6919...the old one had loose throttle shaft, "new" one is tight, swapped in the Truck Avenger vent. The driver's side idle mixture has no effect even though I shot carb spray into hole shooting a small geyser up through bleed. If I push in electric choke manually when warm, vacuum goes up to nearly 20 inches.
Am I missing something? Really acts like a vacuum leak. Before I pull intake off and replace gaskets or even swap in an old cast iron 4V intake I have laying around, I plan to change the fuel filter, check the volts to the coil and check the fuel pressure. Iv'e worked on Holleys, Ford 302s and 5.0Ls since I was 15...53 now and this one is stumping me.
Thoughts? Ideas? Please share experiences!
Thanks!
Mike