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Hi guys looking for a diagram for my 69 Bonneville 428 firing order.I put in a new hei and thought I had the right diagram  but maybe not and seem the only ones I can find on line are for everything but the 428.I can't seem to get to kick over so hoping that is the problem or may have to try to get tdc again.Which is another question .I used the tabs and rotated until my mark is at 0.Will that change now that I went to HEI and should use the number one and not worry about what it says on the tab...

Thanks Terry

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18436572, should be on the intake!

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Thanks I thought it was different because all I found was everything but for the 428.Then found out they are all the same even the Chevy's.Found my TDC and hope this will work if not told I am most likely 180 off ...ahh the joys of the classic's

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I checked everything am at TDC and timing tab is at 0 and tried to fire it up and getting backfire though the exhaust could I be 180 off and need to point the mjy rotor towards number 8 and not 1??

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If you want to be absolutely sure, pull the left side valve cover (drivers side). Rotate the engine around till #1 intake valve compresses and comes back up. Watch the timing mark as that occurs. Stop when the timing mark reaches timing tab area, anywhere, your ready to fire #1. Point the rotor at #1. Make sure it's at #1 otherwise you could be a tooth off.

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Hi..I used a whislte and when it at the highest pitch looked and my timing mark was between 0 and 2 rotor pointing at # 1 .Now I am wondering since I bought those spark plug wires you make yourself if maybe a couple aren't so good and won't fire or make it back fire.It did back fire a little but then again I seen fuel shoot though the carb which i was told is a sign it's off 180.

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Are you sure you have the firing order in the correct direction?   Pontiac fires reverse direction from Chevy. Counterclockwise.

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Yes took a copy of the firing order diagram 1-8-4-3-6-5-7-2 and when I wired it started on the drivers side one wire at a time  and followed the diagram .

firing order (2).jpg

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Justa checking.   It will backfire or no power if it starts with the order reversed.  Good luck.

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OOPPS one more question ...when turning it the 180 it more important to move the whole distributor and keep rotor pointed to #1 or to also move rotor into the 180..I just dropped back down and turned the whole thing 180 but kept the rotor at #1 or am I just chasing my tail by doing that.And I can maybe another problem as the vacuum advance is now to the passenger side it really close to a raditor hose which might be problem when timing.Thats Why I was thinking only the rotor and shaft are at 180

They say if it's out 180 will do the same and that is what it has done a slight backfire to nothing but maybe fuel spitting out the carb..But that diagram is the only they show on the net for all Pontiac's

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Put dist back to original position w/vac adv.  Then rotate the rotor/shaft to #1.   Go past #1 as it will rotate back when dist is fully seated.  Mark #1 on dist housing then move rotor to 1.  Make sure timing mark is on pointer 1st. Might have to do this again if you try N start and it does the same. Pull the cap and if rotor is 180 off, Justa move the rotor back to #1.  Should be good to go.

Edited by JUSTA6

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Remember one more thing - Pontiac distributors rotate counter-clockwise!!!!!   If you are use to working on a Chevy SBC, they rotate clockwise, so be careful. More than one person I know has forgotten that little detail.

 

Edited by Frosty

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Do I want to put the dist vacuum advance back to the driver side? I am TDC with rotor facing my #1 plug and flowered the wiring diagram .Most of the guys at work which have the sbc chevy's said they never had the advance on the driver's side that is why the thinking was it was out 180.With that said I made up the wires could I have broken some of the carbon wiring while clamping them and that won't let me fire it up?

Here is the order I did the wiring  the #1 wire is at the top not quite at 1 O'clock then going counter clock wise 8-4-3-6-5-7-2

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1 hour ago, Tetru said:

Do I want to put the dist vacuum advance back to the driver side? I am TDC with rotor facing my #1 plug and flowered the wiring diagram .Most of the guys at work which have the sbc chevy's said they never had the advance on the driver's side that is why the thinking was it was out 180.With that said I made up the wires could I have broken some of the carbon wiring while clamping them and that won't let me fire it up?

Here is the order I did the wiring  the #1 wire is at the top not quite at 1 O'clock then going counter clock wise 8-4-3-6-5-7-2

Vac advance usually goes to the drivers side, vacume connect should then be pointing towards the carb.  Not the firewall... Actually you can make any spot #1 that the rotor is pointing at, then follow the firing order.  As long as engine is set up at top dead center pointer at timing mark and rotor pointed at #1. (only way to be 100% sure is pull the valve cover, intake valve under the intake runner to that cyl. Put a socket on the crank bolt and rotate engine. watch for the intake valve to depress, now put a pencil in the plug hole and finish rotating till to dead center,  now your dead on with rotor pointing at #1,  timing mark is at pointer) then rotate the dist to advance or retard as needed after starting. If it backfires, bump the engine til timing mark is at pointer again, check rotor location. If not pointed at #1.....make it so.

6 hours ago, Frosty said:

Remember one more thing - Pontiac distributors rotate counter-clockwise!!!!!   If you are use to working on a Chevy SBC, they rotate clockwise, so be careful. More than one person I know has forgotten that little detail.

 

That was my 1st impression as well and had em check it further up in the thread.

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Humm think that is the problem had the vacuum advance towards the fire wall will have to adjust diet to give me more room that said if it is to far towards firewall will it act the same not wanting to start

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Your lining up the timing marks 1st, right?   Look close  is there another timing mark within a 1/2in on either side of the mark your using on the harmonic balancer?  My 421 has 2 marks.   If so try the other.   The vacume advance mod should be pointing directly at the driver side valve cover.  This is more of a "room to advance or retard the dist" without vac/advance hitting something,  also saves clutter on too much vacume line.  If your on the timing mark, the rotor is facing #1 and it backfires or sputters, then line up the timing marks again. If the rotor is facing #1, then pull dist up just enough to move the rotor facing 180 or directly facing away from #1.  Should fire.   Are you using a stock Pontiac HEI or aftermarket?    Are you getting spark? Pull a plug wire and check while turning over.   

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Yes lined it up first but actually when I used the whistle at the loudest for tdc it was at the lower end of 0 on the tab never knew it might have two will look in the morning ok away from #1 should take me to #8 had the advance pointing around the fender to firewall so that would explain a lot.yes getting spark and is I guesscan after market got it from summit and told it would fit the car coil is inside so nothing fancy just an up grade

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I know it seems hard, but it's not.

The only things that actually matter are:

1) When #1 cylinder (front, drivers side) is at TDC  on the compression stroke (remember that TDC occurs twice: once on compression, once on exhaust)

2) The rotor inside the distributor is pointed to the terminal on the cap that you have #1 spark plug wire connected to, and

3) The rest of the wires are sequenced counter clockwise according to firing order.

That's it.

The other items such as which way is the vacuum diaphragm pointing, and which specific terminal you have #1 wire connected to do not matter at all as far as the engine being able to start and run.

However, the orientation of the vacuum diaphragm can have an effect on you being able to properly time the engine (it may hit the intake and prevent you from turning the distributor like you need to), and for 100% correct concours level nit-picking restoration the terminal for #1 plug wire should be pointed "more or less" towards the drivers seat.  But as long as you have those first 3 items right, the engine should run.

A couple of easy ways to identify TDC compression stroke:

Remove all the spark plugs and stick a rag or paper towel or something over #1 spark plug hole then crank it over with the starter.  When the rag gets blown off, that's TDC compression.

Do the same thing, only stick your thumb over the hole and have a buddy crank the engine over.  You'll be able to tell when you're at TDC compression.

Once you're sure you're at TDC compression on #1, look to see which cap terminal the rotor is pointing at and connect #1 wire to that one.  Wire the rest in firing order sequence, working counter-clockwise.

 

You can do this.

 

Bear

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Pretty I have TDC a few yrs ago I bought this whistle that screws into #1 plug and when you hear the loud noise you should be there and thats what I did.And my timing mark is between 0 and 1 and figure that should get me close and set my dist down with rotor pointing at the #1 plug .The only thing I did before I think was having the vacuum advance more towards the first wall then towards the carb. And went by the diagram on the web with #1 plug at around 1 o'clock and going in counter clock wise 1-8-4-3-6-5-7-2 .I haven't tried it yet just getting ready to..

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Well after I work up went out to try and fire it up and nothing.With the advance all the way towards the block actually just about hitting it started to pop a little from the exhaust.As I slowly moved towards the firewall got nothing but could smell gas.Had TDC and pointed the rotor towards #1 and the timing mark just about at 0.My number plug is at around 1 o'clock as the diagram shows.Have the firing order going counter clock wise.The only thing left to try is that it is 180 off there doesn't seem to be anything else I can do.

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Sorry bro...should not be this much trouble.  Summit has a Q and A tech you can talk to if you call.  That would be the way to go if you have to return it and go back to your original dist.

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Sometimes you can not reley on the TDC Mark on the balancer..Especially If it's old..Over a period of time the outer ring of the damper tends to move around as the rubber deteriorates..they will show TDC even though the timing will be retarded..best way is pull drivers side valve cover and look at when the  valves are opening and closing..use a socket and a breaker bar..Pull the engine thru manually..Will Spin real easy if you pull all the plugs out of it..Watch the rockers on the #1cylinder when the exhaust valve closes..and the intake valve  opens all the way then closes... Stop right there stick an old pushrod or something into the spark plug hole when you make contact with the top of the piston..Slowly rotate the engine when you feel the piston if it's  still going down..Keep rotating when you feel the piston coming back up both the valves should be closed..when the piston is at it's highest point and both the valves are closed that is TDC..Look at the timing Mark on the damper see where it lines up with the timing tab and Mark it for future reference..Put the vacum advance towards the front somewhere around the 7 O'clock position..place the cap on the distributer take a marker put a Mark on dist.body right in the center of where the #1 plug wire goes pull the cap back off..Drop the dist. In with the rotor button pointing towards # 1..after you do that rotate the base until the Mark you made on it lines up right to leading edge of the copper contact of the rotor tighten the holddown just enough to where you still move it by hand..reassemble everything..Engine should start and run....remember dist rotates CCW move toward firewall to retard..away from firewall to advance...Hope this helps..one other thing make sure you have a spark.....

Edited by TWO LANE BLACK TOP

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Hi was thinking about that when I had a 57 Chevy a friend found TDC and never looked at the timing mark hexsaud the same thing the age and wear he said find it drop the dist at #1 and go from there think I have been making myself crazy try to get tdc marks and throwing it out of wack so in the morning will get it and not look at the timing marks

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Yes lined it up first but actually when I used the whistle at the loudest for tdc it was at the lower end of 0 on the tab never knew it might have two will look in the morning ok away from #1 should take me to #8 had the advance pointing around the fender to firewall so that would explain a lot.yes getting spark and is I guesscan after market got it from summit and told it would fit the car coil is inside so nothing fancy just an up grade

Forgot to say the vacume is around 5 O'clock position so will have to change that but will tight unless the whole unit is moved from passenger side to drivers but was told not to do that

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You can put the vacuum advance diaphram any postion that you want wherever has the most clearance....as long as the rotor is pointing towards #1..when distributer is dropped into the engine

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