# Can’t get my 400 rebuild to start.



## jimmy328 (Oct 12, 2011)

I’ve been trying for days to get my rebuild started (on the run stand); I have spark, compression and fuel but it won’t fire up. On the compression stroke on the #1 piston the timing mark on the harmonic balancer comes up to around 0 to 6 degrees before TDC (this seems correct). I’m sure I have the firing order correct. I’m thinking back of what I could have done wrong during engine assemble and think “timing chain” keyway error (possible 3 keyways). As I recall there was only one way to install the crankshaft and camshaft gear but perhaps I'm wrong. The picture shows that the dots on these gears line up. Before I go through labor of tearing down the front end I hope to find help here.

Thank you,
Jim
67 GTO, 400


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## Red1970GTO (Jun 25, 2011)

Old Pontiacs used the 6 o'clock and 12 o'clock position on the timing gears, but newer ones use the 12 and 12 positions. Just off hand I don't recall when that changed, but you may wish to recheck that setting. Espcially if you put a new cam in it. Everything will look good, but you could actually be 180 degrees off...


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## the65gto (Oct 9, 2008)

Stupid stuff to check:
If you have a helper, remove #1 plug and put your finger over #1 hole, you will feel the compression coming up on TDC.
The rotor should be pointing to #1 Spark plug wire at this time.
Bump the engine, rotor should be pointing @ #8. Not #2. 
You can measure ~12 volts at coil in both run and start position.


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## jimmy328 (Oct 12, 2011)

Red1970GTO said:


> Old Pontiacs used the 6 o'clock and 12 o'clock position on the timing gears, but newer ones use the 12 and 12 positions. Just off hand I don't recall when that changed, but you may wish to recheck that setting. Espcially if you put a new cam in it. Everything will look good, but you could actually be 180 degrees off...


I get an idea of what you wrote and will further research. I did in fact put the CAM in myself (carefully) which is at 6 o’clock and crank at 12 o’clock which is dot to dot on the gears. Could I still be 180 off even though air blows through the hole at #1 and the timing mark on the balancer shows up at zero degrees?


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## Matthew (Feb 11, 2011)

Jim, I agree that your firing order looks correct, but I would not have expected to see number one plug wire where you have it. Normally it would be at about 1 o'clock as you look at the distributor from the front of the engine. Matt


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## 05GTO (Oct 6, 2004)

jimmy328 said:


> Could I still be 180 off even though air blows through the hole at #1 and the timing mark on the balancer shows up at zero degrees?


Where is the rotor when this happens, the rotor should be in the position to fire the first spark plug. If not raise the distributor turn the rotor 180 degrees and reinstall the distributor and try again.


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## jimmy328 (Oct 12, 2011)

05GTO said:


> Where is the rotor when this happens, the rotor should be in the position to fire the first spark plug. If not raise the distributor turn the rotor 180 degrees and reinstall the distributor and try again.


Here’s the rotor “position” when air blows through the #1 cylinder (must be compression?) and the timing mark on the balancer is near zero degrees. This would be sort-of towards the fire wall if the engine was installed.


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## PontiacJim (Dec 29, 2012)

Flooded?


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## jimmy328 (Oct 12, 2011)

PontiacJim said:


> Flooded?


It's not flooded.


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## PontiacJim (Dec 29, 2012)

OK on the flooding.

Points or electronic in the distributor?
Points - reversed wiring at the coil? Resistor wire? Correct point/dwell setting?
Electronic ignition - 12V to coil?


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## PontiacJim (Dec 29, 2012)

Believe your cam/crank gear timing marks are off. My book shows 1969-1973 as your cam gear timing dot at the 12 o'clock position instead of the 6 o'clock position you have yours at.

Did that myself with a '68 GTO I had using the later timing alignment and could never get it to fire up again. It was a very worn car (back in the day) and I was not going to sink any more money into it, so I parted it out. Years later I learned what I had done.


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## PontiacJim (Dec 29, 2012)

Found this thread. I may be reading it wrong, but it sounds like you can move your distributor firing order to compensate for the timing marks? Pontiac 400 timing chain - Chevelle Tech

CHECK OUT MY POST 17. Maybe this will help????


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## jimmy328 (Oct 12, 2011)

PontiacJim said:


> OK on the flooding.
> 
> Points or electronic in the distributor?
> Points - reversed wiring at the coil? Resistor wire? Correct point/dwell setting?
> Electronic ignition - 12V to coil?


Yes, I upgraded to an MSD Ready-To-Run distributor and MSD tech support has provided great support. I get spark; 12 volts RUN position and about 10 volts START position. So I think I fouled up on the rebuild but I don’t know where.


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## PontiacJim (Dec 29, 2012)

jimmy328 said:


> Yes, I upgraded to an MSD Ready-To-Run distributor and MSD tech support has provided great support. I get spark; 12 volts RUN position and about 10 volts START position. So I think I fouled up on the rebuild but I don’t know where.


OK, then its gotta be the timing. Check out my previous post and the link.


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## Lemans guy (Oct 14, 2014)

Jimmy, just thinking along with you. Does the distributor advance turn freely?

Just to make sure it is not stuck advanced. I see you dist vac can hose. Is it hooked to full manifold vac or ported? And have you tried starting it with it remove and plugged. A very tight vac can can pull timing even on cranking.

Just a thing to check. I agree with Jim though, when you have checked spark and compression, timing is suspect.

Also what is gap on the plugs, a wide gap can really drive you crazy and make hard starts. You get spark at the plug wire but inside the cylinder under pressure of compression, not as easy. 

That should fire if the timing is set right....

Nice job by the way...it is something simple...you will get it....

Just frustrating:banghead::banghead:


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## 05GTO (Oct 6, 2004)

You are close, turn the distributor counter clockwise a little, reconnect the #1 spark plug, pour a little gas directly into the carb and see if she will fire,


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## PontiacJim (Dec 29, 2012)

Still searching the web on this one. You may still be OK. Here is another blog that mentions "indexing" your cam -if I read it correctly. This is for a Chevy 350, but it sounds like the same issue. You may have to pull your valve cover to observe your N01 cyl valve action. Pull your distributor up/out. Watch for the exhaust valve to open, then close. Next your intake will open as your piston travels down. The intake valve will close and piston will move up on its compression stroke. At the top of the stroke is where your spark will fire. If you know that your piston is at the top of the cylinder on its compression stroke, drop your distributor in so the rotor will line up with your No1 wire on your cap.

This might work??


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## the65gto (Oct 9, 2008)

jimmy328 said:


> Yes, I upgraded to an MSD Ready-To-Run distributor and MSD tech support has provided great support. I get spark; 12 volts RUN position and about 10 volts START position. So I think I fouled up on the rebuild but I don’t know where.


Is MSD ok with only 10v starting?


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## mallsup (Feb 24, 2015)

Grounded?


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## jimmy328 (Oct 12, 2011)

PontiacJim said:


> Still searching the web on this one. You may still be OK. Here is another blog that mentions "indexing" your cam -if I read it correctly. This is for a Chevy 350, but it sounds like the same issue. You may have to pull your valve cover to observe your N01 cyl valve action. Pull your distributor up/out. Watch for the exhaust valve to open, then close. Next your intake will open as your piston travels down. The intake valve will close and piston will move up on its compression stroke. At the top of the stroke is where your spark will fire. If you know that your piston is at the top of the cylinder on its compression stroke, drop your distributor in so the rotor will line up with your No1 wire on your cap.
> 
> This might work??


Jim, how can I tell what valve is intake and exhaust?


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## jimmy328 (Oct 12, 2011)

Butler Performance (Pontiac specialist) told me I should have set the crank/cam sprocket dots at 12 and 12 rather than what I did which is 12 and 6. Apparently though 12 and 6 can still work. I brought the #6 piston up to TDC and had the rotor pointing at the wire for #6 cylinder but still won’t fire up. As it’s cranking I make slight adjustments to the distributor. I rechecked the firing order and it’s correct. What am I not understanding?

Answers to above suggestions:

I checked out the link and its helpful
The distributer rotates freely
I removed the dist vac hose, makes no difference
MSD Tech support seemed to be okay with 10 volts in START position
It’s ground to the block and run-stand


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## Goat Roper (Oct 28, 2014)

Did you try priming it with some fuel?
You should at least be getting a pop or a backfire through the carb or something.

Are you getting compression on all 8 with a gauge?


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## Bensjammin66 (May 12, 2009)

1 8 4 3 6 5 7 2 *Counter* Clockwise. 

12/6 12/12 on cam/crank gears doesnt matter it just turns #1 into #6 as far as spark goes. 
12/12 gear setup means that the rotor is ready to fire #1. 12/6 is rotor to fire #6. Might be 180 off. 

No one has mentioned a leak down test on the valves and rings. 
Who did the machine work? 
Do you know you have compression across all 8? If so how do you know? 
Did you adjust all the valves one at a time with the lifter on camshaft flatspots rotating the engine cylinder by cylinder? 

Test your 12v+ wire that powers the coil at the dizzy, you have 12v cranking AND in the ON position?

Just a few things im thinking of with the motors that we've put in that didnt fire right up.


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## jimmy328 (Oct 12, 2011)

Goat Roper said:


> Did you try priming it with some fuel?
> You should at least be getting a pop or a backfire through the carb or something.
> 
> Are you getting compression on all 8 with a gauge?


Yes, I certainly primed it with fuel and once in a while I get “minimal” popping and backfire. I used a compression gauge on all 8 cylinders; if I recall correctly it was about 125.


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## Bensjammin66 (May 12, 2009)

If your cam gear is at 6:00 and the crank is at 12:00 the rotor is pointing to #6 not #1. 
You can leave the gears where they are if so, just rotate the engine once to then have your cam gear at 12 and crank at 12, now the rotor is pointing to #1.

I just seen your pic and im pretty sure thats your issue. Cam is at 6:00 and crank is at 12:00 in the picture. The rotor is pointing at #6 when in this position. In the 6/12 position like your pic shows like i said above just spin the crank once to be 12/12 and now the rotor will be pointing at #1, then put your wires on 8 4 3 6 5 7 2 counter clockwise from that point. Bet she runs!!


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## jimmy328 (Oct 12, 2011)

Bensjammin66 said:


> 1 8 4 3 6 5 7 2 *Counter* Clockwise.
> 
> 12/6 12/12 on cam/crank gears doesnt matter it just turns #1 into #6 as far as spark goes.
> 12/12 gear setup means that the rotor is ready to fire #1. 12/6 is rotor to fire #6. Might be 180 off.
> ...


A local machine shop bored out the block. The owner said the heads were fine (they only had less than 1000 miles on them).

As for adjusting the lifters; I should probably pull the valley pan and set valve lash which I need to learn about. At first I went with the specs and adjusted the nut on the rockers to 20 foot pounds. The owner of the machine shop said not a good idea so right now I just have them snug.

About 12 volts in ON and 10 volts in START. I’m getting spark at the coil and spark plugs.

I brought #6 to TDC and set the rotor pointing at #6 wire.


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## 64gp (Apr 6, 2015)

HI! Sharing my experience self With you.
I had same issues on my 64 389 engine that i restored With oversized piston,rings,camshaft and etc....

After reinstall it wouldnt fire.
camgear positioned at 6:0,crank at 12:00 is right.(when cyl#1 is at top btdc)
Then i installed the distributor and positioned the rotor until it hits #1 ,and distributorcap With #1plug at one o clock at the back of firewall.

The engine gaves good spark,lot of fuel from carb ,adjust the Stock valvetrain to 25 ft.lbs torq.,,,,but nothing fires...
sometimes flames shoot thru carburettor and engine hosted??
must be ignitionfail....and yes it was...180 degree fail

When #1 cyl where at btdc, its the same for #6 cyl.
so in my case when i thinked #1 were at topit was actually #6 and the rotor pointed at#6 and ofcourse it wouldnt fire.
Open the distributor and lifted it a bit out till a can turn rotor 180 degree to point at #1 on the distributorcap....voila...it started at once and run great..
hope this would help anyone...thanks!!!


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## Bensjammin66 (May 12, 2009)

Where is the cam right now Jim at 6:00 or 12:00?

Remember 6/12 gear orientation the rotor points to #6. 12/12 rotor points to #1. 

As far as setting the rockers go, it kind of depends what type you have but at TDC for each cylinder you can set both I and E rockers for a base line. 

With #1 @ TDC compression stroke grab either pushrod and gently twist it with your fingers. Begin to slowly tighten the rocker nut till you need decent force to twist the push rod. Give the rocker nut a 1/4 - 3/8 more turn and that should be good enough preload to run it to break it in. Rotate engine 90 degrees each time and repeat for 8 4 3 6 5 7 2. 

Ideally you want the valley pan off for initial settings so you can spin the motor and adjust the rockers/lifters when you can see that the lifters are on the exact opposite side of the cam lobes but this will get you running initially.


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## jimmy328 (Oct 12, 2011)

64gp said:


> HI! Sharing my experience self With you.
> I had same issues on my 64 389 engine that i restored With oversized piston,rings,camshaft and etc....
> 
> After reinstall it wouldnt fire.
> ...


I might have to try this.


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## jimmy328 (Oct 12, 2011)

Bensjammin66 said:


> Where is the cam right now Jim at 6:00 or 12:00?
> 
> Remember 6/12 gear orientation the rotor points to #6. 12/12 rotor points to #1.
> 
> ...


Well; I brought #6 piston up to TDC (felt air blasting past my thumb) and the timing mark on the harmonic balancer landed at around 4 degrees before TDC. So now I have the rotor pointing at the #6 wire.


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## PontiacJim (Dec 29, 2012)

OK, let's start from the beginning. Need more info.

What year engine?
What cubic inch?
What are the numbers on the heads (middle exhaust port)?
Screw-in studs(high perf.) or pressed-in bottleneck studs(low perf.)?

You mentioned you torqued the rocker arm stud nuts to 20ft pounds. This would make your heads the bottleneck low-performance press-in studs. 

If you have the screw-in studs and do this, your valves are remaining open -bad thing.

I think you meant pulling the valve cover, not the valley pan. No need to pull the valley pan as this requires pulling your intake.

Pull your valve cover off the No1 cylinder bank. Looking at the rocker arms, going from left to right(or front to back), the first rocker arm on No1 cyl is your exhaust valve "E". Next rocker on No1 cyl is the intake "I".

The sequence is EIIEEIIE for your rocker arms/valves.

So get the No1 cyl to Top Dead Center(TDC) on the compression stroke. Then set your distributor (or pull it out and re-set) so your rotor is pointing to No1 on your dist.cap. This should get it close enough to fire up.

Now, you could have the wrong harmonic balancer/timing pointer on the engine which will throw everything off if you try to set your timing marks by it. I bought a junkyard 72' 400 that had the later solid hub '76 balancer. Wrong hub for the engine so the pointer did not correctly line up at all with he hub marks. I set my initial timing by it to fire up the engine and could not get it to fire -like you. I finally played around with the distributor moving it about until I got it to pop and run. It ran poorly and my exhaust manifolds, within a few minutes, began to turn a deep red - way too hot. I shut it down immediately. Did this a couple times and could not figure it out. Thought it was the "tight" 110 LSA giving me problems so I called the cam company. They said I should not have that problem because of the cam and it was most likely my timing at my distributor. I can't remember if I had to advance it more or retard it more, but I did as the cam tech said. The car smoothed out, ran fine, and my exhaust manifolds stopped turning red from being over heated. *Moral of the story is* I had the mismatched timing hub & pointer.

So, give us more info on your engine. Do a few more checks. Let us all know.:thumbsup:


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## Bensjammin66 (May 12, 2009)

One more thing to add is #1 is NOT the forward most cylinder on Pontiacs. That is actually #2. Common mistake by many.


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## PontiacJim (Dec 29, 2012)

No1 cylinder is the forward most cylinder on the drivers side.


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## Lemans guy (Oct 14, 2014)

So that advance mechanism inside that dizzy turns freely? 

and you are sure the coil is strong.

Fuel stream is strong when you bump the carb and fuel flows freely?

Since you have the compression the mixture is wrong or the spark is not, present, too weak or at the wrong time.....that is what Jim & Ben and the gang are following.....

These can get maddening. A rebuilt stock dizzy at the local auto parts is $40 bucks. You cou,led try that and swap a coil out as well. That dizzy could be off, you think you are setting it at 10 degrees and it is really 30...that advance mechanism has to be right. Stuck springs weights even stuck vac can arm can mess you up.

Did you try a shot of ether? Don't like it usually but it will fire when mixture is bad, too rich or too lean.....at least it would isolate it to fuel...


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## jimmy328 (Oct 12, 2011)

I fired up my 400 build today; it started within a few seconds, idled relatively nicely and maintained 80 PSI of oil pressure. My goal was to let it run for 20 to 30 minutes for break in; however, the water temperature kept climbing and after about 8 minutes it hit 230 degrees; I had to shut it down. There’s good air flow (suction) through the radiator with the fan/clutch/shroud set up and I could see water flow through the radiator when I removed the cap (after it cooled of course).

Upgraded parts are:
Aluminum radiator, 7-blade fan with new clutch, shroud, 11 bolt timing cover, FloKooler water pump and MSD Ready-To-Run distributor.

I called Butler Performance (amazingly helpful) to order more gaskets and explained my problem. They said I need to check “initial” and “total” timing and to check the carb to see if it’s running to rich. I’m ignorant in both areas and I need to research and learn this concept (I’m in the medical field, muscle cars are for fun).

Meanwhile: I’m open to suggestions.
Jim

P.S. Thank you to all the knowledgeable people on this forum/thread and their willingness to use their valuable time to help someone they never met.


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## PontiacJim (Dec 29, 2012)

I had the same experience with my last 400 rebuild. The water temp skyrocketed and the exhaust manifolds were cooking hot. I shut it down as well. Did this a couple times, same thing each time. Called my cam maker because I thought maybe a cam problem. It was not. They said it sounded like a timing issue. They told me to advance my timing. That did it. Retarded timing can make your engine run hot in short order.

Timing is a critical part of your engines performance. The distributor has to be set up for your engine/cam/car. Read this page from the Chevelle page. It is not your Pontiac, but it gives you a really good insight into what needs to be done with the ignition timing: timing advance runs hot, retard runs slow - Chevelle Tech


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## Bensjammin66 (May 12, 2009)

PontiacJim said:


> I had the same experience with my last 400 rebuild. The water temp skyrocketed and the exhaust manifolds were cooking hot. I shut it down as well. Did this a couple times, same thing each time. Called my cam maker because I thought maybe a cam problem. It was not. They said it sounded like a timing issue. They told me to advance my timing. That did it. Retarded timing can make your engine run hot in short order.
> 
> Timing is a critical part of your engines performance. The distributor has to be set up for your engine/cam/car. Read this page from the Chevelle page. It is not your Pontiac, but it gives you a really good insight into what needs to be done with the ignition timing: timing advance runs hot, retard runs slow - Chevelle Tech


This is spot on advice. The timing is off. A $189 HEI Pontiac Dizzy from Summit with the gold advance springs from Mr Gasket part number 928G can be set at 16 initial with 20 mechanical all in by 3200. Itll run REAL strong and cool for you. If you already have an HEI, original or otherwise just set the initial to 16 degrees with the vac advance capped, rev it up with a light on it and see how much mechanical advance you have then make the necessary changes to have 36 degrees total. 14-16 initial and 36-38 total in by 3000-3200 is ideal in my experience.


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## the65gto (Oct 9, 2008)

jimmy328 said:


> I fired up my 400 build today; it started within a few seconds, idled relatively nicely and maintained 80 PSI of oil pressure. My goal was to let it run for 20 to 30 minutes for break in; however, the water temperature kept climbing and after about 8 minutes it hit 230 degrees; I had to shut it down. There’s good air flow (suction) through the radiator with the fan/clutch/shroud set up and I could see water flow through the radiator when I removed the cap (after it cooled of course).
> 
> Upgraded parts are:
> Aluminum radiator, 7-blade fan with new clutch, shroud, 11 bolt timing cover, FloKooler water pump and MSD Ready-To-Run distributor.
> ...


So what changed since the last post where it would not start, just the new dizzy? I had a similar problem with mine on a rebuild, skyrocket temperature. After third try, just got in and drove it. Shortly after, temp came down to normal.


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