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phil400
Cochise

Canada
456 Posts

Posted - 26 Sep 2015 :  5:52:11 PM  Show Profile  Reply with Quote
I'm getting some light ping at 1800-2000 at part throttle, if I unplug my vac can it goes away completely, no ping above or below that rpm, never at WOT.

I'm running 14* initial@ 750rpm, 34 total all in around 3000, using one heavy spring and one medium spring, factory weights, 14* from the vac can.

I'm using the stock vacuum can and I made a stop plate so it only adds 14* verified with my timing gun.

Everything else about this combination is perfect, running direct vacuum source not ported, idles @ 850 rpm, just nice so can tell it's not the stock cam but not slow enough that it sounds rough or choppy, runs nice and cool even in heavy heavy traffic, WOT is great, throttle response is great.

What else should I try. Make another plate and limit vacuum advance to 10*

Thought?

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"

Blued and Painted
Chief PONTIAC

USA
3409 Posts

Posted - 26 Sep 2015 :  7:27:58 PM  Show Profile  Reply with Quote
Yes. What else should I try. Make another plate and limit vacuum advance to 10*


Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.
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phil400
Cochise

Canada
456 Posts

Posted - 26 Sep 2015 :  11:20:45 PM  Show Profile  Reply with Quote
Ok thanks.

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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Blued and Painted
Chief PONTIAC

USA
3409 Posts

Posted - 26 Sep 2015 :  11:41:58 PM  Show Profile  Reply with Quote
what type distributor?


Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.
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phil400
Cochise

Canada
456 Posts

Posted - 27 Sep 2015 :  01:13:17 AM  Show Profile  Reply with Quote
It'a an original HEI but with a ACCEL super coil, the dizzy itself is all stock GM except for the springs, thanks again man.

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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phil400
Cochise

Canada
456 Posts

Posted - 06 Oct 2015 :  07:32:47 AM  Show Profile  Reply with Quote
So I figured out why my car was pinging lightly, my vacuum advance limit plate had moved allowing the can to add all 25* which made sense because all of a sudden my idle had jumped from 800-850 to 1000rpm, so anyways I put it back properly and decide to go for a ride, this was Saturday around 5pm.

I'm going along everything is going fine, then all of a sudden the quits, this is the first time in 16years I've ever been stranded with my t/a, had to have it towed home.

My gut was telling the ignition module in the dizzy, I've seen this before there's no warning when they go the engine just quits.

So Sunday morning starting from zero to be sure I'm chasing the right problem I check for spark.....I have spark??... I put the wire back on the plug and the engine fires right up..WT?

I'm still thinking it's the module that's heat damaged that's why it worked when cold but looking for other opinions thoughts

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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Admin
Ye Olde Webmaster

848 Posts

Posted - 06 Oct 2015 :  08:48:58 AM  Show Profile  Reply with Quote
Phil--
One day I drove my TA about 15 miles to a paint shop to get an estimate on my car. During the return trip to the house, it was pouring rain--in buckets. I had to slow to see because the wipers couldn't clean the rain from the windshield. Then all of a sudden my engine quit. I glided over to the curb. Puzzled, because I had not gone through any standing water. The engine cranked over and started. The next day, I fired the engine and pulled the car out of the garage. Hours later the engine would not fire up? It acted like it had no spark.

As it turned out, the HEI ground strap had corroded just enough to break the ground. It took me a while to track the problem down, so I'm suggesting that you remove the HEI cover and check out all the terminals especially the ground strap.

I've had a problem with the module only once and it was a broken green wire from the pick up which was repaired and a dead module in the computer controlled HEI in my old 86 Blazer 4x4 K5 truck. When it went it died--kaput. I'm not certain whether they fizzle out or not based on my experience. I kind of believe it's like a light bulb. It blows out--done--get a new one.

Bill

"Dedicated to keeping the classic Pontiac engine alive."

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phil400
Cochise

Canada
456 Posts

Posted - 06 Oct 2015 :  10:34:18 PM  Show Profile  Reply with Quote
Ok thanks, guess I'll pull the dizzy and go over it.

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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phil400
Cochise

Canada
456 Posts

Posted - 12 Oct 2015 :  9:02:58 PM  Show Profile  Reply with Quote
I've got a lot going right now and don't really have time to futs around troubleshooting my original dizzy, so I went ahead and ordered a summit brand dizzy for the car, I need a quick fix so I can enjoy for the next month and a half before the snow hits, during the winter I can take the time to rebuild the original dizzy properly.

Anyone running a summit brand dizzy? I figure worse case I'll swap my center plate, weights and springs from the original to give me the curve I want

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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cortcomp
Coyote

USA
5339 Posts

Posted - 12 Oct 2015 :  9:12:49 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
I am running the summit brand dizzy (HEI). It advances early, and WAY more than they say...bill checked it for me, was still advancing at 6000 rpms. Other than that no issues, he set it up to come in when i wanted and done by 2800 or 3k rpms, i slept better knowing that i wasn't at 65 degrees total at 4700 rpms.
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phil400
Cochise

Canada
456 Posts

Posted - 14 Oct 2015 :  07:50:01 AM  Show Profile  Reply with Quote
Ok thanks Cort, do you know if Bill used the weights and center plate that came with the dizzy or did he swap in some original GM ones?

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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cortcomp
Coyote

USA
5339 Posts

Posted - 14 Oct 2015 :  09:31:29 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
I would have to find the paperwork, and it might have went with that car when i sold it. But i'm pretty sure he used a weight kit. Let me check my email, maybe we discussed it there.
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cortcomp
Coyote

USA
5339 Posts

Posted - 14 Oct 2015 :  09:37:49 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
Here are some snippets from our conversation on that distributor:

"Your curve copies that profile. It never reached a plateau. Which means it is slow and gradually moves up the RPM range. I tested it to 6400 rpm. The HEI read 26 degrees at 6400. It was only 9 at 2000; 15 at 3000; 19 at 4000; 23 at 5000. This is not a performance curve. BTW I set my machine to zero advance at 800 rpm. There was no advance until 1400 and it jumped from zero to 5 at the rpm. It would be preferable to have this curve in my 3000 rpm."


"I ran different springs and came up with a conclusion, we need to add a stop to the mechanical to limit advance to 20-21 degrees. What I saw was that with different springs the mechanical continued to advance, quicker, but higher as rpm increased.

To give you an example. With one set of springs there is zero at idle; 4 @ 1000; 11 @ 1600; 14 @ 2000 and 21 @ 3000. This is where it should stop. However, it continues to climb 26 @ 4000; 30 @ 5000 and 34 @ 6400. Again this is quicker but higher. Limit this curve to 20-21 @ 3000 and we have a good performance curve for your engine. "

"800/0
1000/4
1200/9
1400/10
1600/11
1800/12
2000/14
2200/15
2400/17
2600/19
2800/20
3000/20.5
"

So, looks like spring swaps only, same weights, and positive timing stop added. Bill would likely have more info on what springs/where he got them. Timing on that dist never stopped, and was a lazy curve. Lighter springs let it go too far so it needed a stop, but come in faster.

IIRC the paper in the box talked about it's timing profile and how it was blueprinted came in early and stopped, etc. Just a generic curve to fit a wide variety of engines without worrying about warranty returns, classic summit.

Module and coil, etc were good, Bill said no misfires as he tested up to like 6krpms, and never gave me trouble.
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phil400
Cochise

Canada
456 Posts

Posted - 14 Oct 2015 :  10:15:29 PM  Show Profile  Reply with Quote
Ok thanks, seeing how the season is almost over, I'll probably run it with the slow curve for now even though I know It wont run as well as it did with the curve it had with the original dizzy, but atleast I'll be able to drive it alittle more till the snow hits.

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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