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bentwings
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Discussion Starter · #1 ·
Anybody know the gap between the reluctor and the mag pickup?? It seemed pretty wide when I had it apart but dumb me didn't check it as every thing was ok earlier.. You have to remove the snap ring to get the mag pickup plate up high enough to clear the end of the vac advance so I did move the plate but it fits very tighly with the snap ring in place..

I have brass feeler gages.

.016 seems to be the number I heard. I did check MSD site but I could not find it.

Msd says the resistance of the mag pickup should be 500-700 ohms so I'll also check this in the morning.

I replaced the vac advance as I blew out the diaphram in the original and now the car won't start. I'll check the spark in the morning but the car ran a couple hours before this.

The dist is in correctly and the timing is very close. I have had problems starting if the battery is even slightly low.
 

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Copy and pasted from the MSD forum and one of their tech advisers:D:

"You need to have .018-.030 air gap. the closer the stronger the signal but what we are trying to avoid is the reluctor hitting the mag pick up"

So at .016, should be close. Mine is at about .020 if I recall the last time I had my small diameter pro billet apart to reinstall the vac canister.

Dave W
 

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bentwings
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2,608 Posts
Discussion Starter · #3 ·
Thanks. that's a great help.

I have a feeling that the new vac adv is "tweeked" a little and has caused the pickup plate to be twisted to the outside. So I'm on the way to the shop to go thru it again. There is very little radial play but some vertical over the snap ring. There were 2 spacers under the snap ring.

Thanks again.
 

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The engine not starting would bother me more - it sounds like you had a backfire to blow that canister. I ran mine for a very short time with the dist locked which in effect is what you have/had - and it ran like @#$%, but did run. Suspect that if you did backfire, might have a massive vacuum leak especially with a supercharger - but you know that:D
 

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bentwings
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2,608 Posts
Discussion Starter · #5 ·
Nope, no backfires have occured on this car. I think what happened is that it gets pretty hot behind the blower as the vac lines were all very hard and one was even cracked. i suspect that the vac adv diaphram also got old and hard and sudden boost simply broke it.

Anyway I checked the pickup resistance and it was 619 ohms. Also check anothe MSD and it was 598 so it was good. I also checked the gap and it was .024-.026 on one reluctor fin.

Also checked the spark according to MSD instructions... giant spark....you don't ever want to get in the middle of it....not at this age....probably woulod stop the heart dead.

Here is the egg on my face.....:embarrass:embarrass:embarrass

Here is what happened.....it is very tight behind the blower with vac lines, PCV and other wires. Even with the hood standing straight up it is a real stretch to see anything back there. Add limited light and disaster is immenent. read on haha

Well I dropped the dist back in and lined up the reluctor as always. Most of the time I can hit the timing right on the money and never more than 2-4 deg off. well This time the dist went in but not quite all the way down. I could only barely see one side of the hold down. I snugged it up enough to allow the dist to turn with a little force. Unknown to me was that the hold down was not on all the way. So when I first cranked the motor it barely fired aboout 2 cyl then nothing. what happened was that the dist jumped out slightly and disengaged the gear. the motor then spun over untill it dropped in about 180 deg off. No I did not miss on the first attempt. I have bet money on the install and won and I rarely bet on anything I can't win. haha

Ultimately I went back to first day in auto shop 1959. removed the valve cover, turn the motor over untill #1 intake is closing, turn motor over untill the desired timing mark is lined up. Drop the dist in and align the reluctor up about 1/3 over the magnet #1 cyl. Check that the cap #1 is in the proper position and install the clamp....make sure it is alll the way on the dist. this time.

I cleared the area and made sure my 10# fire extinguisher was handy ( I was alone in the shop so saftey is vital) Car on jack stands.

I turned the key on and let the fuel pump run for a few sec and hit the switch. Boom it fired and ran in less than a turn of the motor. Checking the timing and it was right on at 32 deg at 2500 rpm. I plugged in the vac adv and it was working correctly. Idle speed went up 200 rpm (only 2 deg vac adv at 10 inches.) otherwise it works as it is supposed to.

So out for a ride today 100 deg outside and turn on the air to cool me off. the car runs great. A little smoother at cruise. I only had a few minutes for cruising today with the 4th and all but it definitely is back. Now I need to recalibrate the carb a little but that has to wait for the weekend after my senior baseball practice and game.

So thanks to those that helped out and as you can see not everyone is without mistakes.

Moral.....don't assume anything......:spank::spank:

Check check and check again.
 
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