I need help! I have a 78 Regal with a 70's 350 in it with 80's 624 heads, stock intake, spread bore adapter, Holley 670 carb, and new cap, rotor, plugs, and wires. I just recently put long tube headers on. The carb is vacuum secondaries so it's always had a slight dead spot, but once I finished the header install, I went to drive her and she has a huge dead spot now. If you start her up, she has fast idle choke, so you wait a minute for her to warm up, then tap the gas and the idle drops way down. Then you go to put her into gear and as soon as you are in gear and touch the gas, she falls on her face and dies unless you are really really really slow on the gas and baby it way more than normal and allow the motor to slowly rev up. Put it back in park and it fires right up again. Why is this? Is this a tuning issue? I have tried to adjust the distributor and idle thinking it was perhaps idling too low but no success. What am I doing wrong? Also, if you punch it to the floor, she used to falter for a half second, then come on strong. Now if you punch it to the floor, she falters and dies. Always fires right up even if she dies. So I don't think it's a major issue, just tuning. I don't know how to tune. PLEASE HELP! 🙁
TUNING?
- Thread starter MEAN78REGAL
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use a vaccuum gauge, it could be the power valve, and you could be running it rich...try keeping the choke open
check the accelerator pump to make sure it squirts fuel when you hit the gas. also, adjust the idle mixture screws.
Advanced 4 degrees but I really think it's just an adjustment issue because if during any of the time the car is running, if you let off the gas when she falters, she stays running and runs really good.
Good news! I did adjust the mixture screws a bit and loosened up the accelerator pump nut a little since it was barely moving even at WOT. She doesn't seem to have much of a dead spot at all but some fine tuning may be in order since I just went back out to start her after letting her sit for an hour or so and I had a hard time getting her to start. Had to hold the gas to the floor and had a pretty strong smell of gas. I think maybe the accel pump was loosened up a bit too much or the mix is too rich.
good so far!!! congrats
but you really should get a vacuum gauge and use that to do the fine tuning, and a timing light. unfortunately every adjustment in the carb will affect the timing and every change in timing will affect the carb.
for performance you usually want 10-12* ignition advance
but you really should get a vacuum gauge and use that to do the fine tuning, and a timing light. unfortunately every adjustment in the carb will affect the timing and every change in timing will affect the carb.
for performance you usually want 10-12* ignition advance
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