# 60 degrees of initial advance??



## 65Poncho (Mar 31, 2017)

Getting my car running after years of sitting. After dialing in idle (16 inches of vacuum) and float levels, she ran pretty good. She idles fine. Pushes you back in your seat. Only rough spot is that she surges when you're cruising with light throttle. (Thought maybe that was too much vacuum advance or lean.)

Then I checked the timing. With vacuum advance plugged, she showed 60 degrees advanced initial! Huh? Used a different timing light. Same thing. No knocking during idle or driving. I turned the distributor to take out some advance. It immediately ran worse. Couldn't get down to the teens or it would die. Hmm... Got a piston stop out and confirmed the dampner hasn't shifted. TDC on the timing tape is still TDC for #1 piston. 

What am I missing?

65 GTO with 400. 6X heads. 770cfm Holley. Pertronix HEI. MSD. Only 1,000 miles on the build, but she has sat for years at a time.


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## bigD (Jul 21, 2016)

Unhook vac line & plug it off. 

Find out what your TOTAL MECHANICAL ADVANCE is first. For most Pontiac engines it should be 34-36 degrees. 

Check the rpm at which you reach TOTAL advance. 

If that number is above 3500, you need to buy an advance curve kit, and substitute a weaker spring, til you get the total to stop advancing at between 3000 & 3500 rpm. Most want their curve to start advancing at about 1000 and increase to total, by 3000. 

AFTER you have the MECHANICAL curve set correctly, then you can hook the vac line back up & see how much advance the vac can adds. 

I've read that you don't won't it to reach above 50 degrees. Some say mid 40's is enuff. If your dist has an adjustable vac can, you can back it off all the way, and if that's too low, adjust it back up in small increments. If your vac can is not adjustable, you can buy a Pertronix adjustable. Or, you can buy a Crane vac advance kit, which comes with an adjustable vac can & weaker advance weight springs. 

https://www.summitracing.com/parts/...yrsnLf21E_-Mbt_fmNQ4dvqC16lF9cJQpOBoCy1Tw_wcB

https://www.summitracing.com/parts/crn-99600-1


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## 65Poncho (Mar 31, 2017)

Thanks bigD. I measured advance with vacuum advance disconnected and plugged. I know the targets to shoot for. Where I'm at a loss is that it shows 60 degrees initial and likes it! Throttle response isn't as great in the lower end of the rev range, but I thought for sure it would be knocking and pinging if I had several times more initial advance than anyone I know. No detonation that I can hear. And she starts right up every time. Something's up and I don't know what.


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## BearGFR (Aug 25, 2008)

I agree, something's not right here. If it really has 60 degrees in it I'd expect it wouldn't even start. Please forgive me "in advance" (lol) for asking a really dumb question, I'm not trying to insult your intelligence or anything, but you are connecting the light to the front cylinder on the driver's side, right?

Bear


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## bigD (Jul 21, 2016)

"...you are connecting the light to the front cylinder on the driver's side, right?..."


Yeah, you can hook it to either #1 or #6 wire, since the zero mark on the balancer will hit the zero mark on the timing tab when every time either #1 or #6 piston is at TDC of it's compression stroke. It's a bit easier to use #6 , on a Pontiac, since you point the light from the pass side. 

The timing light doesn't know which wire it's hooked to. It just flashes when the charge comes thru the wire. So, you can hook it to each wire, to make sure every wire is firing. But, for timing purposes, you must hook it to either #1 or #6 wire.


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## 65Poncho (Mar 31, 2017)

Thanks for the replies guys. No offense taken!

I know my light is on #1 wire. Driver side at the front closest to radiator. Two different guns got same reading. Neither gun of the dial back variety.

Plug order on cap is right. 1,2,3,4... Just kidding. : ) 18436572 counterclockwise. 

I pulled distributor last night. Put #1 piston 12 degrees before TDC on the compression stroke (watched intake valve open and close to confirm that), then took off the distributor cap. You would expect rotor to be pointing right at #1 terminal. It was noticeably past #1 terminal. I think this confirms that indeed it has a LOT of initial advance. Rules out the gun and the tape being the problem I think.

I can play with weights and springs, but what has me stumped is why would it want 60 degrees? Doesn't make sense.

If cam and crank gear were out of whack it wouldn't want THAT much advance would it? Timing chain and engine build only has about 1,000 miles on it. (And I've timed it before since the build!) Also, why would it run reasonably well if cam and crank were way off.

When I degreed in the cam, I remember talking with a builder about advancing or retarding the cam itself. I remember he was asking if I had a crank offset key. I can't remember what I did on that if anything. But if the cam was a little advanced or retarded, it wouldn't dramatically change my ignition timing, right? 60 degrees at idle isn't a tweak.

I really appreciate all ideas and help.


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## 65Poncho (Mar 31, 2017)

Just checked my timing tape. Measured the circumference. Then measured the distance of 40 degrees worth of marks. It's the right one. Still scratching my head.


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## bigD (Jul 21, 2016)

Hey, maybe it's just playing a April Fool's joke on you. I'm pretty sure an engine will not idle @ 60 degrees advanced.

Hey, just for kicks, humor me and hook a light up to #6 wire. It should read exactly the same as when on #1 .


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## Lemans guy (Oct 14, 2014)

65Poncho....That surging and bucking at light throttle cruise too much timing advance...

if your centrifigal and base is high, adding in 16 more from vac is way too high....

that said I have had guys say their car runs pretty good, when we pull dizzy and put it on the machine it has so much adavnce cannot believe they drive it like that!

some will have 40 in the weights and adding more on the base......then another 22 from vac....

what usuaslly saves them is heavy springs nd it keeps all that advance from coming in until way up in the rpm range.....

60 at idle....seems like it would be awful hard to start that....

you want 36 total Mechanical and 46 to 48 with vac....

hot cams can take a little more base and a little less cetrifigal....

the vac can add ten more:nerd:

sometimes the worse knocking is the knocks that you don't or can't hear!


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## Lemans guy (Oct 14, 2014)

PS....double check for a crossed plug wire...as was mentioned ....

be double sure that you are not just clipped on the wire at the No 1 plug but that that plug wire is actually at the corresponding place on the cap''''

sorry, if you already verified, but this can happen easy...


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## BearGFR (Aug 25, 2008)

It's sure a head scratcher.... I'm wondering if the timing chain is "off a tooth" or so but I haven't thought that all the way through yet to decide if that would have anything to do with the price of frijoles in Tijuana... or if an extreme amount of ignition lead could otherwise "make up" for that such that it could run reasonably well.

Bear


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## Lemans guy (Oct 14, 2014)

distributor gear must be oriented right as well, with dimple matching rotor tip. Slipped balancer ring, 

stuck Dizzy weights...stuck open;.... will pull the advance out at lower RPMs..

don't know his idle RPM but could be high say 1000 or higher...

stuck or springs off will send timing soaring....

vacumn leaks that create an extra lean idle and therefore allow it to fire earlier.......

from a recent reassembly....or crossed plug wires or crossed ignition module wires should all be checked.


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## bigD (Jul 21, 2016)

BearGFR said:


> It's sure a head scratcher.... I'm wondering if the timing chain is "off a tooth" or so but I haven't thought that all the way through yet to decide if that would have anything to do with the price of frijoles in Tijuana... or if an extreme amount of ignition lead could otherwise "make up" for that such that it could run reasonably well.
> 
> Bear


Now this jogs my memory. Back in around 1971, I had a '69 GTO, which I'd bought new, in early '69. At somewhere around 40k miles, the timing chain jumped, because of the plastic teeth which came on the cam gear, back then. Those teeth were almost guaranteed to fail by 50k miles. 

The engine would not start. A guy I knew, moved the dist around, as I tried to crank it. Well, it finally cranked. But it had no power at all. Would not even get up to 50 mph. But, I did make it home, less than 10 miles away. At that time I knew almost nothing about the insides of an engine. So, I got a neighborhood mechanic to take a look. He discovered the jumped chain. Also had a couple of bent pushrods, since the valves were open at the wrong time.

Apparently, there was no valve or piston damage, since I drove it passed 60k miles, then successfully raced it for 2 seasons, without any internal changes at all. 

Therefore, I assume that it may be possible to have the timing only 1 tooth off, and still have at least reasonable power, considering. ?????


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## geeteeohguy (Feb 2, 2008)

Static-time it. Put the engine on #1 TDC compression, and verify that the rotor is pointed directly at #1 on the cap. You're balancer should be at TDC, or 0 degrees. This is with the engine not running. IF your car was actually base-timed at 60 degrees initial, it would not start or even crank...if it did, it would kick back so hard it would probably break the starter or the ring gear.


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## Lemans guy (Oct 14, 2014)

Yes I agree with GeeTee and BigD great points as well......

I went back to your description of the rotor being way advanced when you pulled the cap.....

I don't know if you are sure,.... but the bottom gear dimple must match the rotor tip and if it does not it throws the timing off 13 degrees....if in addition it was dropped in a gear off,.....you can get off quite a bit.....

so back to the beginning, pull the dizzy, check the gear, make sure the module wires are on correct weights turn freely, dizzy shimmed properly at bottom,...timing can mess up there as well...

then as GeeTee said starting points on engine TDC etc and re-drop the dizzy...

nothing fancy try the drop at TDC, pointing at #1 , which of course you double verified...

you will get it!:nerd::nerd::nerd:


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## PontiacJim (Dec 29, 2012)

Seems others have experienced this thing as well. Many ideas and things to check, but ultimately, the reason was never found. A few comments point to the HEI/MSD with one mentioning the wires reversed internally. A big cam with a lot of overlap and low/dished compression was another thought because the engine needed more advance to work correctly with this combo. Check out this post: Timing way off, but runs great? | The H.A.M.B.


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## Lemans guy (Oct 14, 2014)

yeah, when I have revesed the module wires accidentaly on the distributor machine it gives an erratic spark reading, so that is worth checking....

but it does feel like the timing light is just reading the wrong cylinder,,,,

no 3 maybe, and therefore it seems to run good and when you turn it down it does not, but you aew actually running at 30 BTDC not 60 and turning it down to past 0 and it stalls

all the while your light showing you 60 to 30....just something to really verify.....

but lots to check, if it starts easy just cannot see it really being 60....


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## 65Poncho (Mar 31, 2017)

Thanks for all the input. Still trying to figure this out.

Pulled and went through the distributor. It is a Pertronix HEI unit. Weights felt a little "grabby." Cleaned them up. Put the quickest opening copper springs in. Turned vacuum advance down to 12. Confirmed with mityvac it does open with vacuum.

Put it back in. Checked and double checked order. #1 piston was confirmed to be 12 degrees before TDC on compression stroke. Pointed rotor at #1 . Wouldn't start. Turned dist both directions all the way. Wouldn't start. (Sigh)

Pulled the dist, advanced it about 45 degrees and put it back in. Starts right up! Put the light on it. 50 degrees. Take timing out, she stumbles. Add it, she likes it. Can only turn it to 60 so I do.

BigD, I took your suggestion. Switched timing light to #6 wire. (I want this to be operator error more than anyone) It also reads 60 degrees!

Idles smooth. Starts up first turn of the key. Will push you back in your seat.

Questions:
The dimple on the distributor. I don't know anything about that. Is that just for stock HEI's or would it effect my Pertronix unit?

Can someone tell me how to shim my distributor? Currently it just sits down on the block.

How do you tune your timing without a timing tape? Advance it until you hear spark knock then dial it back?

Guess I'll check for vacuum leaks. That sounds fun. I've watched some YouTube videos. Neither propane or starting fluid sound overly safe. : )

And now, the SUPER dumb questions because I feel like I'm losing my mind with this. When looking at the crank pully, it turns clockwise, right? So timing tape should wrap around it clockwise, right? Rotor spins counterclockwise, right? Twisting distributor counterclockwise advances timing, right? How far do I need to separate my plug wires (they are newer, performance oriented wires)?

I really appreciate the help guys.


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## 65Poncho (Mar 31, 2017)

Oops. Shoulda said, twisting distributor *clockwise *advances timing.


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## BearGFR (Aug 25, 2008)

Crank does turn clockwise when viewed from the front -- the top of it spins towards the drivers side.
So... looking down at the Zero on your timing tape from the top, the markings that read advance should extend towards the right/drivers side as they increase. If you're looking up at zero from underneath the car (Zero on the bottom of the balancer) they should extend towards the passenger side.

You're making all your measurements with the vacuum advance disconnected and the hose plugged, right?

This is too weird....


Bear


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## bigD (Jul 21, 2016)

"...Can someone tell me how to shim my distributor? Currently it just sits down on the block.

How do you tune your timing without a timing tape? Advance it until you hear spark knock then dial it back?

The shim goes at the bottom of the shaft, between the gear & the housing. Many say you should reduce the space between the gear & housing, to around .012-.020, with shims--preferably one thick shim. Others say the gap doesn't matter, because the Pontiac dist turns counterclockwise. I won't get into an argument one way or the other. I'll just say that I've always shimmed mine, and have had no problems by doing it. And, many others have done it, thru the years. Any shims used must be hardened. Shims made of soft material can result in metal shaving in the bottom end. 

http://www.pontiaczone.com/forum/showthread.php?p=433030

https://www.summitracing.com/parts/mor-26140/overview/

Many time their engines using a GOOD QUALITY "dial back" timing light. These eliminate the need for a timing tape.

https://www.google.com/webhp?source...e+your+engine+with+a+dial+back+timing+light&*


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## 65Poncho (Mar 31, 2017)

Hmmm.... Now I'm thinking about my distributor gear. I'm running a mild flat tappet cam. But I have a hi flow oil pump. I have a bronze distributor gear on there. I think I swapped it out for some reason. And I think I remember (it's been 15 years) someone telling me I better get that off of there for some reason. 

What gear should I be using? Stock steel or aftermarket bronze? Now that I think about it, that gear may be worn. When I was looking at it the other day, the teeth looked thinner along the outside edge. Is my hi flow pump chewing it up? Could that be affecting my timing?


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## 65Poncho (Mar 31, 2017)

Found original HEI. Took steel gear off and used it to replace the bronze gear. Indeed, that gear was getting munched up due to the high flow oil pump.

Now running even MORE initial advance than 60 degrees. Thought I'd ratchet it up to see how it ran as I approached a level where I heard detonation. Still haven't gotten it to ping.

Have no earthly idea what to think of this. Open to any ideas. At this point, vacuum leaks and wiring are the only leads I have. Will check both.


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## PontiacJim (Dec 29, 2012)

65Poncho said:


> Found original HEI. Took steel gear off and used it to replace the bronze gear. Indeed, that gear was getting munched up due to the high flow oil pump.
> 
> Now running even MORE initial advance than 60 degrees. Thought I'd ratchet it up to see how it ran as I approached a level where I heard detonation. Still haven't gotten it to ping.
> 
> Have no earthly idea what to think of this. Open to any ideas. At this point, vacuum leaks and wiring are the only leads I have. Will check both.




You want to ensure you have the correct dist. gear material that matches the type of cam used. "Remember to check ignition timing; as the distributor gear wears, the timing will retard." You mentioned shimming the dist. gear. Make sure you still have some "up & down" play in the shaft. You don't want to shim it then tighten the dist. down and bind it up on the cam gear. Some dist. use a gasket under the housing where it goes into the block. Can't recall if Pontiac has this or not and I have only found a couple to use these as most don't seem to have them or they have been completely worn away.

Found this which gives you a quick insight into gear material: bad day got worse with my small block - Page 3 - Yellow Bullet Forums

The fact that your timing changed when you changed the gear sounds like it might have indicated dist. gear wear. Is it possible that the cam gear is shot? Can you hit a flashlight down the hole and peer down in and look?

At this point, it almost sounds like a pick-up problem within the distributor - something incorrectly phased or improperly assembled. I would email Pertronix with the serial number of the dist. and your problem along with an itemized list of those things you have done in trying to solve it. They may know right away what it is.

*Timing mark? What timing mark? Who has a timing mark? We don't need no stinkin' timing mark! * :lol:

I used to do this with my engines as many of us "old guys" have when you don't have a timing light or can afford one. Timing an engine for maximum advance by ear is simply advancing the dist., taking it on a road test, and putting the engine under load whether up a hill in top gear or accelerating hard. If you hear the audible "pinging", then the dist. is advanced too much. You then back the dist. off a few degrees and repeat until it no longer pings. I usually just keep the distributor hold down clamp/bolt snug enough so I can turn it and yet not too loose that it will twist out of time. Keep in mind that in doing it this way, you can adjust for the "ping" with the tank of gas you have, then fill up and the next tank "ping" on you - outside temps/engine heat or even various road conditions can place more strain on the engine to pull and cause ping. So sometimes you have to find that happy medium or be ready to adjust your timing as needed if you are so inclined.

If you have a loud exhaust, it may be difficult to hear the pinging under hard acceleration or even highway speeds with all the road/exhaust noise going on. geeteeohguy lost his 428 under these conditions because the pinging was slight but he drove the car over long periods of high speed driving. Pinging can destroy your engine if too severe or allowed to continue for long periods of time. Some light pinging can be normal such as mashing the gas in 4th gear when you are only going 35 MPH - too much load on the engine when it should have been dropped into 2nd gear to get the RPM's up and the car accelerating. But if you were to do this and hear pinging, get the pinging to stop by backing your foot off the gas or putting the car in a gear that will pull under acceleration without pinging, but don't allow it to continue to ping and think it sounds "cool". 

Here is a little more on the subject: Any tips on timing an engine by ear? | The H.A.M.B.


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## Lemans guy (Oct 14, 2014)

65.. I think you should substitute a known good HEI dizzy, get a rebuilt one at your local auto parts, and try again. Or if you have access to a known good one......at least then you will know if you are looking at engine issues if that does not work.

I agree with BigD on shimming Dist, I have found lots of slop in those and generally they benefit from adding hardened shims. Multiple hardened shims can be used, morose sells a hardened shim kit. I just shimmed a 65 corvette Dist runs way better, from .. gap was almost 1.0...took it 010....it eliminate the RPM wander at idle, as the Dist would walk up and down the gear..now rock steady.

Also a dial back timing light, read correctly, where you read the timing from the light, the mark is always on zero..( I know you know this I am thinking out loud).....

which I am sure you are doing....it just feels like you are reading the timing on another cylinder. Yet you checked...what I find interesting is that when you turn it back, retard it to teens, it stalls...so about 35 to 40 back,...so if it was really 35 to 40 not 60 it would stall about there.

You just be a couple of teeth off,....have you tried walking it back, two teeth or one at a time?

When you try to set it up with the timing mark at 12 Advanced, or ten, you can sometimes advance it more than you think,......:smile3::nerd::nerd:




But the gear wear is of interest as Pontiac Jim said....


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## Lemans guy (Oct 14, 2014)

Ps yes Pontiac does have a paper gasket that goes between Distributor housing and engine flange.....Jeg's, Summit they all have them.
They keep oil from leaking at that point and should be replaced when Dist pulled.....although slight they do raise the Dist just a tad and will keep it from jamming on top of oil pump flange,..it engages it without sitting full weight on it. Lots of car have them totally worn to nothing, but if you pull the Dist replace it, keeps oil in mostly......


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## Lemans guy (Oct 14, 2014)

65....Since you have a Petronix HEI,...did you put on the copper L stops that go over the distributor weights?

They have 3 sets that adjust the amount of timing advance that the weights travel they are unique to Petronix Distributors.....

I am sure you did, but if not your total advance would be way out even at idle.....


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## 65Poncho (Mar 31, 2017)

Uh, I don't know anything about stops in the distributor. Here's a pic of my setup. I chose the copper springs as they were the quickest to open and I have a 65 GTO (fairly light) with a manual.


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## 65Poncho (Mar 31, 2017)

Currently there's .024 of play using the stock shim.


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## Lemans guy (Oct 14, 2014)

did you get an ignitor 1, 2 or three?


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## Lemans guy (Oct 14, 2014)

65 call Petronix and work out what you got.........


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## Lemans guy (Oct 14, 2014)

I don't see a module in that photo? where are the connections for it? it looks like you are hooked directly to the dist pulse.....but with HEI a module plugs in to that yellow connector,......


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## Lemans guy (Oct 14, 2014)

are you trying to convert an HEI distributor with a petronix points conversion pkg?

not he same......GM orignal HEI dist has the coil inside the cap and is a larger diameter,..

in 65 your car had a points distributor.....that dist you are showing is an HEI....not a points conversion to dist where petronix points conversion kits are used......

talk to petronix...but you may need an HEI refresh kit..

.proform sells them

I think you may be thinking an original GM HEI....is the same as a Petronix electronic conversion.....

but it is not ..the electronics are different.....if you have an HEI which you do....a Petronix module to convert an original points dist is not correct.......

if petronix made this whole dist,....something else again...or did you buy the petronix conversion kit....

sort that out with Petronix tech line.....I think you may be using a points conversion kit for an HEI...but I still don"t see the module either way.....no wires...


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## Lemans guy (Oct 14, 2014)

65...look at the black plastic module hooked to the connector in this photo....

that is also a photo of one some arm stops which was method Petronix used in their own dist to manage mechanical advance.....

I don't see the black platic module in your photo which is an HEI....module

petronix 1,11,111 look much different and are for points conversions.....

anyway hard to tell from here.....I hope Petronix can get you sorted out.....


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## Lemans guy (Oct 14, 2014)

Ok so you are running an MSD box off this....

Still got to talk with Petronix...let us know what happens....

You will get it!


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## 65Poncho (Mar 31, 2017)

It's an aftermarket Flame Thrower HEI distributor from Pertronix, not a conversion.
HEI Distributors


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## Lemans guy (Oct 14, 2014)

65 got it....sorry for my ramblings,...

I notced in the Petronix sheet they say they have "engineered a special coil and module configuration", to help spark yada yada....

but could this new algoitum make it incompatible with your MSD?

have you tried just running the petronix straight without MSD box.....it could be that they have changed the interface somehow and they won"t work together correctly...

just a :nerd:maybe


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## musclebirds (Jul 19, 2020)

Did you ever figure it out iam having exact same issue on a fresh rebuilt 455 with GM Hei unit.


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## PontiacJim (Dec 29, 2012)

musclebirds said:


> Did you ever figure it out iam having exact same issue on a fresh rebuilt 455 with GM Hei unit.


Make sure you have a new & correct harmonic balancer and the correct year timing cover as the original balancer has an outer ring that can move and the wrong timing cover from a different year may not line up with the marks on the balancer.

Timing Light Issue? "the guy put his induction clip for the timing light on the wire attached to the #1 cylinder. However, that wire DID NOT go to the proper location for the #1 socket on the distributor cap (for whatever reason). And, yes, with the timing light, it WOULD show 60+ degree ignition timing."

Make sure you wires are in the correct placement using a diagram showing the position of the No. 1 distributor cap terminal. The early Pontiac's used the No. 6 distributor cap terminal.


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## BearGFR (Aug 25, 2008)

musclebirds said:


> Did you ever figure it out iam having exact same issue on a fresh rebuilt 455 with GM Hei unit.


First things first. Make sure your balancer marks aren't lying to you - that an indicated TDC is actually TDC.


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