Don't mess with a quadragunk, get a holley.Hello,
I'm new here to the forums. I am working on my uncle's 78 Z and am really struggling with getting a really bad stumble out of it. Anything more than an 1/4 throttle when driving it, the car starts missing really bad and doesn't want to pick up RPM. Here is the info on the car:
Engine- 100% original, no modifications. 128K miles
Exhaust- factory manifolds, 2.5" pypes system with crossflow muffler.
Fuel system- new fuel tank, new sending unit & filter, new stock style fuel pump. All new rubber fuel lines. Hardline from pump to carb replaced. New fuel filter. I went ahead and replaced all of the vacuum lines as well.
current carb setup- APT- 3 turns out, idle air mixture screws, 3 turns out. peak vacuum observed, 18". The APT was 4.5 turns out when I took the carb apart originally, I've tried this setting, 4 turns, 3.5, 3, 2.5 and 2 turns and it doesn't seem to make much of a difference.
timing- adjusted timing by watching vacuum gauge. was able to get another 2" of vacuum when adjusting the timing for a final reading of 20"
ignition- new wires, cap, rotor, ignition module(did use grease when installing) and plugs(R45TS gapped at .045")
I purchased a rebuild kit for the Q-Jet from Cliff Ruggles last year, went through the carb, reinstalled it with a new manifold to carb gasket and fired it up. The car idles well, revs fine, but runs absolutely terrible when I get it out on the road. I have not put a timing light on it yet, but the main reason for that is I can't find a timing tab to check it. Shouldn't it have a timing tab on the drivers side of the of the engine at about the 2-3 o'clock position of the balancer?
Could I be chasing my tail with the carb and it be something as simple as an ignition coil starting to go out?