hei issues

Pontiacpower

Pontiacpower

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hello Pontiac forum. I'm having issues with an hei swap and ive run out of ideas. I got a 76 distributor out of a grand prix and put a new coil icm and harness on the hei. swapped the springs and weights with a mr gasket kit.
now for installation I used the acc prong in the fuse box and ran a wire from there through the fire wall to the batt terminal on the distributor. I then hooked up the hei harness and this car just will not start. mind you I did mark where the rotor was pointing and what cylinder it was pointing to before taking out the distributor.
after trying checking connections and power to the acc fuse I tried turning the engine over 180 degrees and reconnecting the plug wires and still nothing. does anyone have any suggestions for my predicament? any and all help is appreciated.
 
I am thinking the ACC Prong in the fuse box will loose power while cranking.
 
I checked voltage while cranking and it gets at least 9 volts. I tried using all 3 fuses and 2 of them have popped now I only have one left:mad:
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check the power wire to the windshield wipers with a test light or a voltmeter for a full 12 volts or whatever your battery is putting out, with the key in the run position and while cranking.
If you have power under both conditions tap into the wire for your HEI. If you still have a problem check at the plug end of one of the spark plug wires to see if you are getting a spark.
 
hello guys. well I figured out that I was blowing the fuses. the fuse that I hooked in to was supposed to be 20 amp but someone put a 2 amp in there????? after a very long weekend I did manage to get spark to the plugs but now im having issues timing. I set the number 1 piston top dead center on the compression stroke and I also made sure that the rotor was pointing at number 1 on the distributor. so far I cant get this motor going. the only thing I can think of is the weights I put in the distributor. I bought a mr gasket kit off amazon and the weights are a different shape than the stock weights on the hei. they are thicker and they do not close as much as the stock weights either. I feel I am getting to much advance because of this. I know I have spark so I know I have power. these plugs are brand new but I guarantee they are fouled out after the attempts made at starting. ill try a new set of weights and I will post a picture of them for you guys because I would really like to see what some of you might have to say. after getting somewhat familiar with the hei these things absolutely do not look right.
 
so I pulled the distributor apart and I noticed that the distributor I pulled out of the grand prix is set up differently than the points distributor I have. the weights do not point in the same direction Is what I am getting at. did all Pontiac v8 distirbutors spin counter clockwise?
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Pontiac distributor rotors spin counterclockwise and the vacuum advance unit is on the drivers side. Install the stock weights and springs and get the car running before trying to change anything.
 
Did you read the information at the link I provided?

Did you replace the spark plugs and adjust the gap to the new specifications?

Much of what you need to do to convert to HEI has not been mentioned.

The link I provided clearly shows the fuse box to not be a good source for the voltage you need.

As far as the weights and springs take pictures of what you have and what was in the distributor.

If I remember correctly I used to use the medium weight springs and plastic bushings but not the weights for a stock engine. I may be wrong on this yet the information is included in the instructions that came with the springs and weights

The vacuum source for the vacuum advance would also be changed as is the base timing.

Pretty much to be any help to you we will need pictures of what you have and a more detailed description of what you have done.

For example we need to know the distributor you picked up has been confirmed to be a 8 cylinder distributor a 6 cylinder distributor will bolt up yet not work.

Things like this may be obvious to you yet need to be mentioned to us so we have an idea that the work being done is done correctly.

It is also helpful from our view point that when we give you information from a professional reliable source that we know you are following those instructions.

I for one am trying to help solve the problem yet if advice that is provided gets ignored I have no desire to help further and waste my time.
 
thanks for the help so far guys.
well heres how the hei upgrade came about and the steps I have taken so far. my uncle used to troubleshoot for gm so hes got some experience in the area of old school cars. he recommended that I get an hei distributor from the junkyard because my car has issues starting. after the conversation about the benefits and the maintenance ease to using it I went to the junkyard and pulled a hei out of a 1976 Pontiac grand prix. this grand prix had a 350 in it, I believe this is true because the casting on the side of the block between the freeze plugs said 350 and the two letter code on the front of the block indicated that the motor matches up with a 76 350. after I pulled this hei distributor I got a new harness, ignition control module and a set of weights and springs and installed all of these. when I put the distributor in the car I noticed that the weights point a different direction than the old points system I pulled out. this change of direction really threw me off. as for my situation at the moment, I did get the car running today but I did not change how I had the power going to it yet. that will be this weekends project. outlaw sorry I didn't give you solid facts. I did read your article and thank you for the link. I hope you don't think your wasting your time. I really appreciate the help you guys submit. im 21 so I did not have the benefit of working on these old cars until this lemans came along so I apologize if I sound pretty clueless.
 
forgot to mention that I did upgrade the 20 degree vac advance to an adjustable unit on the new distributor.
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Did you change the spark plugs and gap them appropriately for the HEi conversion?

I assume you changed the plug wires because I think the points type wires wouldn't works anyways.

There is two ways to set up the vacuum advance which will effect the performance of this car tremendously.

The first way is for the car to have the base timing set high with manifold vacuum applied to vacuum advance.

As you floor the engine while driving you loose vacuum and ignition advance which prevents detonation.

Normally when a advance is set up like this from the factory the vacuum line will have a in line thermal vacuum switch mounted to the intake manifold.

If I remember correctly it would also have a inline calibrated vacuum restriction ( it was just a plastic round color coded inline device that slowed the release of vacuum under WOT )

This setup left a lot to be desired the TVS ( thermal vacuum switch ) would get brittle and break and even when working properly left a few ponies in the stable.

Back in the day because these TVS were so troublesome we would eliminate the TVS connect the vacuum advance to a ported vacuum source.

This means at idle the vacuum line has no vacuum but when driving down the road or smashing your foot to the floor is when you would get vacuum to the advance.

How much advance you get is decided by base timing the adjustment at the vacuum advance. how smoothly all this worked was dependent on the weights and springs in the distributor.

This left you where you had to tune the base timing on the fly to prevent detonation.

Meaning once you had the advance set up properly, you would loosen the distributor clamp bolt just loose enough to move the distributor by hand but not so loose the distributor would rotate on its own.

Then drive the car down the road listening for detonation while at cruise speed, light acceleration and wide open throttle.

If the car was sluggish you would advance the timing until you heard detonation then backed it off just slightly till the nose when away.

From this point you would drive the car with the AC on and off switching from light acceleration to heavy acceleration making sure the engine is responsive and has no detonation.

If the car drove well you would lock the distributor down.

Once you had the engine somewhat dialed in you would check the timing at idle with a timing light and take note of what the base timing is set to.

This would be your starting point for fine tuning the engine performance.

A smart person at this point would take the car to a shop that had a Dyno and have the carburetor and ignition system dialed in for maximum horse power and torque.

However if your engine has carbon coated pistons and combustion chamber a slack timing chain or needed other work like a carburetor overhaul or replacement even neglected maintenance this work would needs to be done first.

Since you did not post pictures of the new weights next to the old weights or provide the information on what kit you installed I suggest you install the factory weights with the springs that are called for on a stock engine.


Keep in mind that my memory is not what it used to be and it has been many years since I had to work on customers cars with a carburetor and HEI ignition.

This is not a how to fix your car or tune your car it is just a reminder that when upgrading to HEI it will require much more than swapping out a distributor.

If you take the time to research all of this and have your engine tuned properly it will make a big difference from idle to wide open throttle.
 
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You never verified on which side of the distributor the vacuum advance is located, driver or passenger?
 
outlaw you are correct. new plugs and wires are required when doing the hei swap. I purchased some 8.5 mm wires and delco plugs gapped with .045 gap. i will post pictures of those weights when i get home. these weights are thicker and heavier than the stock ones and they don't close as tight as the stocks. these heavier weights would mean quicker advance right? melsg the vac advance is on the drivers side of the engine. i did plug the vac advance when i first got the car running. and timed. then i took the car down the road and adjusted timing until i got favorable results into high rpm.
i must point out that this car is in need of tlc. the 2bbl carb is in need of rebuild, the manifold is starting to tick. i purchased a quadrajet, 4 barrel intake and a set of tube headers off of a gentleman for 100$ last fall to improve my situation.
 
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The heavy weights and ultra lightweight springs is not needed unless you have a fast revving engine and many high performance modifications.

You will want the correct ignition advance throughout the entire horse power and torque curve.

The stock HEI weight set and OEM springs are perfect unless the OEM springs are wore out.

If the car is running great, just sort out the positive wire to the distributor running the correct gauge wire from the right source as mentioned in the link I provided.


Check your timing with a timing light and the vacuum advance disconnected from the vacuum line.

The timing indicator should hold steady and the mark should not fluctuate when looked at with the timing light.

If it the indicator fluctuates this may indicate a timing chain with a lot of slack in it.

To check for slack set the engine to top dead center on number one cylinder rotating the engine in the normal direction of rotation.

Once you have the timing marks lined up remove the distributor cap, the rotor button should be pointing toward number one ignition wire it will be off slightly because of your base timing adjustments.

make a mark on the distributor that lines up where the rotor button is pointing.

Then rotate the engine over by hand using a socket and ratchet in reverse rotation stop turning the engine over the split second the rotor button moves. then look at your timing marks this will show you how much slop is in the timing chain.

If you have more than few degrees slop in the timing chain you may want to replace it before you start demanding more horse power and torque from this engine.

You could have worn rings and or valve seals and guides that may not show up until you increase the compression by replacing the timing chain.

You will want to know this before you start hanging parts on this engine.
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i have the stock springs in there with the new weights at the moment. i checked the timing with a light and the mark on the harmonic balancer is seen 3 or 4 inches below 12 degrees tdc. this indicates extreme advance to my knowlege. but i dont hear the "nuts and bolts tumbling around in the motor" as detonation was described to me.
 
you checked the timing with the hose to the vacuum advance unit disconnected and the idle speed below 1000 rpm?
what is the part number of the Mr Gasket kit?
 
when i checked the timing with a gun i had the vac advance hooked up. the part number that is on my amazon order for the mr gasket kit is 929g. the picture that shows up when you search this on amazon is not the same as the product that i received though so i suppose they could have sent me a different part number.
 
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