Ignition Advance - 73 L82
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Joined: Jul 2003
Posts: 51
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From: Raleigh NC
Ignition Advance - 73 L82
I've been having a hard time getting my ignition dialed in this year and could use some advice.
I've gone over my carb with a fine tooth comb and still have some popping coming thru the intake. This only happens when I get on it. I first started with the secondary metering rods in the carb and determined that richer or leaner has no impact. In fact, stock metering rods make the least amount of popping.
Next, I began to look at the timing. I discovered that the car was getting full advance by 2000 rpm's which could be causing my problem. I purchased an advance curve kit from mr.gasket and it didn't help at all. The stiffest springs in the kit were the same as my worn out set on the car.
Does anybody know when a 73 should have full advance?
Has anybody had a similar issue?
Suggestions on where to get stiffer springs?
Heck...I might be trying to fix the wrong thing here by I have ran out of ideas.
Thanks,
Ron
I've gone over my carb with a fine tooth comb and still have some popping coming thru the intake. This only happens when I get on it. I first started with the secondary metering rods in the carb and determined that richer or leaner has no impact. In fact, stock metering rods make the least amount of popping.
Next, I began to look at the timing. I discovered that the car was getting full advance by 2000 rpm's which could be causing my problem. I purchased an advance curve kit from mr.gasket and it didn't help at all. The stiffest springs in the kit were the same as my worn out set on the car.
Does anybody know when a 73 should have full advance?
Has anybody had a similar issue?
Suggestions on where to get stiffer springs?
Heck...I might be trying to fix the wrong thing here by I have ran out of ideas.
Thanks,
Ron
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
What's your initial timing?
Have you verified no plug wires are crossed? Trace each wire and verify 18436572 on the rotor.
My 80 backfired every single time I hit the gas pedal when I had 5&7 crossed.
-Steve
Have you verified no plug wires are crossed? Trace each wire and verify 18436572 on the rotor.
My 80 backfired every single time I hit the gas pedal when I had 5&7 crossed.
-Steve
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Joined: Jul 2003
Posts: 51
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From: Raleigh NC
initial timing is set to 8 deg with the vacuum advance disconnected and plugged.
Wow 5&7 crossed...I hope you caught it quick. I've heard that's one the biggest no no's since they are 180 apart from each other in the firing order. at higher rpm's that can shatter a piston.
Wow 5&7 crossed...I hope you caught it quick. I've heard that's one the biggest no no's since they are 180 apart from each other in the firing order. at higher rpm's that can shatter a piston.
Thread Starter
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Joined: Jul 2003
Posts: 51
Likes: 0
From: Raleigh NC
Yes, my full advance comes in at about 2000. My guess would have been for full advance by 2500-3000 but not sure.
I laughed when I saw my old springs...they are heavier than the aftermakret set i got but they were so worn out that the gaps didn't close when the tension was removed...now the hard part is to find stiffer springs
Never driven it with the advance hose plugged...only do that when i am working ont he timing.
I laughed when I saw my old springs...they are heavier than the aftermakret set i got but they were so worn out that the gaps didn't close when the tension was removed...now the hard part is to find stiffer springs
Never driven it with the advance hose plugged...only do that when i am working ont he timing.
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Joined: Aug 2001
Posts: 3,685
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From: Waterford Mi
II never figured out why but for some reason my distributor started to advance as soon as I started the motor. The engine idled around 800 rpm's in neutral so when I would try to set initial timing it would already have started advancing. I sent it to Lars to have him check it out and re-curve it and he found the same thing happening. I now run the idle speed down to 600 when I set timing. Then when I adjust it back up it ended up a little higher. Note that when the car is in gear with foot on the brake that the idle speed is about 700rpm. The book said to set my timing at 14BTDC and it now goes to 36 around 2800rpm's with the vacuum disconnected. After setting it to 14 it shoots up to around 18 with the idle back up to 800rpms in neutral. I still run the vacuum advance and have not had any problems.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
Pull it out and send it to Lars or find someone with a distibuter machine. Another forum member has a 73 tha twe did some work to this past winter. He was very disappointed with the results. We narrowed it down to the dist not getting full advance and taking to long to get there. After a trip to the dist. machine and setting the timing to 14 degrees initial it runs much beeter and with more power. The stock settings on distribuers was horrible. If you look at old reports on muscle cars one of the first things done was to recurve the stock dist.
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