Excessive end play in the distributor shaft can cause what is called 'spark scatter' or jitter. Basically you would see the timing mark bouncing back and forth a few degrees with the timing light. This is not usually a problem by itself, but can become a problem if the timing chain is worn and has a bit of slack in it.

And don't think that a new distributor will not have end play. I have seen as much as 0.050" on a brand new distributor right out of the box. Several companies (Morosso, MSD, Mr. Gasket, etc) make a distributor gear shim kit that you can use to set end play. I usually try to get it between 0.010" and 0.015". You don't want it too tight because the steel shaft and the aluminum housing have different expansion coefficients.

If the pickup coil and module are good, there is really not much else that can go wrong inside the distributor. You might check to make sure none of the pickup posts are bent. They should all be equally spaced from each other radially, and line up with the tits on the stator.

But if you decide on the shotgun approach and replace the whole assemby, I would suggest getting an updated distributor that has an improved design pointed cog style pickup. See this link -

http://www.pontiacperforman...es/Dist_Upgrade.html

quote Originally posted by Formula350: But if you decide on the shotgun approach and replace the whole assemby, I would suggest getting an updated distributor that has an improved design pointed cog style pickup. See this link -

The one in there now is already the new design...it's only 7 years old. Shortly after I bought the car it failed in a similar fashion, and I took it to a shop where the distributor was declared to be bad and was replaced (twice actually) before it ran right. I didn't know as much then, (not that I'm super knowledgeable now) so I didn't question it.

quote Originally posted by jscott1: The one in there now is already the new design...it's only 7 years old.

Now you tell us. :-)

So this makes me wonder if the pickup coil and module you bought is for the old style, or the new style, or does it matter????? Hmmmm, yeah at this point I would say you may be better off just swapping in a whole new distributor and see what happens. That would eliminate both the pickup coil and the module as culprits.

quote Originally posted by Formula350: Now you tell us. :-)

Well if you look carefully at the rotor pic you can see the triangle shaped magnets from the new design.



The thing is mine are all rusty as apposed to the shiney ones I've seen pictured. I don't know if the magnets can go bad, but they sure look bad.

Oh and the module is not new, it's a known working good one that I swapped out when I thought I had a module problem that later turned out to be a plugged Cat.

There was a member selling even more improved designed distributors from the 4.3 V6, but I think he's still on vacation and hasn't answered my PM yet.

[This message has been edited by jscott1 (edited 12-29-2009).]

So... did you get it running yet?

Jscott,
I know that you are looking for a rebuild distributor from me and i don't have the tools right know to rebuild one for you so let me shed some light on looking at your wiring. If i follow your wires from the pic of your engine it looks like you have them completely wrong as the timing goes 1,2,3,4,5,6 in a clockwise circle from TDC on the engine. I am sure you knew this but what i am sure you didnt know is that the model everyone wants that distributor in your picture with the triangles has the induction coil on the distributor is very prone to failing. have seen a number of these fail just on a bench test of the distributor right out of the box. If you still have a distributor around and would want some input on how to rebuild it i could call you sometime on the weekend and give you some of my tips on how i do it. I have done about 15 so far and no complaints from any that i have sold nor my car ever failing on me on the highway from when i learned how to do it the first time.
-- matt

Jon,
Pull the dist . and start over. but this time first get the mark and the piston in the right spot first with the dist. out.
I use a button switch (AZ) for the starter and turn over the engine back there)
I have been through this like you. I even had to crank the engine over several times just to double and tripple checking I have it in TDC.(you would be suprised) once all that is 100%, then I add the dist. to the mix, double check the wires( AND make sure you don't pinch the module wires in the dist!!)

When you put it back in make sure it goes down all the way, and the rotor is pointing in the #1 pos (that you have already marked somewhere before you yanked everything)
Go over the plug wires one more time (checkin' )

Should start or do something, then get the old timeing light out

I still don't think #3 wire is in the correct spot on the dist.(but that would not make it not start)

call me and we can go over it on the phone!!

quote Originally posted by Formula350: So... did you get it running yet?

IT'S ALIVE!

And in the famous words of many of our great leaders, "It wasn't my fault!"

I decided to do this scientifically so I got the piston stop and I wanted to verify Top Dead Center. I marked the timing mark and I put in the piston stop and cranked the engine (By Hand) over in both directions and marked where it stopped. TDC is in the center, and this is what I got:



Without even getting out the timing tape I can see that the harmonic balancer has not slipped.

Next I wanted to verify that I was on the compression stroke. I got a pressure gage so I could be 100% certain that I was on the compression stroke and not the exhaust. These motors make surpisingly little pressure at 1 RPM, but with me cranking it by hand I could see a small spike in pressure when the mark went by on one revolution versus the other. So I was certain I was on the compression.



And then I looked at my distributor and it was right on #1



So at this point I pull the distributor and compare it to it's replacement



The one thing I notice is that the magnets on the new one are at least 10 times stronger than the old one; the old one nearly freewheels, (foreshadowing).

So I put everything back together just as I had taken it apart



and then after connecting the battery charger....

She fires up and purrs like a kitten! I still need to fine tune the base timing but it's 99% there now.

Conclusions -

1) Even the Cardone Distributors suffer from failing magnets after as few as 7 years. They must gradually lose strength and then at some point they no longer put out enough of a signal for the coil to read.

2) A new pickup coil cannot adequately compensate for failing magnets. The car will run, (barely) but the distributor is still no good.

3) I am not a complete idiot... I can replace a distributor, cap, rotor, wires, plugs and coil correctly.

4) It's very difficult to photograph plug wires in an unambiguous way. I checked them a least a dozen times, so I knew they were right, yet some pictures raised enough doubt that I began to wonder if I made a mistake.

5) MSD blaster coils may stress the modules, but they won't cause a car to run poorly unless it's defective out of the box.

6) Revin's module was not the cause of my car being broken down

7) Garage doors need to be lubed, especially if they haven't been raised in over a year.

8) It's much more fun to drive a Fiero compared to working on them.

Interesting info about the magnets, but...

If your harmonic balancer has not slipped and #1 piston is at Top Dead Center, why isn't your timing mark over by where I've indicated with the red line?

quote Originally posted by jscott1: I decided to do this scientifically so I got the piston stop and I wanted to verify Top Dead Center. I marked the timing mark and I put in the piston stop and cranked the engine (By Hand) over in both directions and marked where it stopped. TDC is in the center, and this is what I got: Without even getting out the timing tape I can see that the harmonic balancer has not slipped.

quote Originally posted by Patrick: If your harmonic balancer has not slipped and #1 piston is at Top Dead Center, why isn't your timing mark over by where I've indicated with the red line?

This picture just shows that the timing mark machined into the balancer is halfway between the 2 marks he made with the piston stop, as it should be. He did not say that crank was at TDC for the picture.

Glad to hear you got it running. That is too nice a car to be parked for so long.

quote Originally posted by Formula350: This picture just shows that the timing mark machined into the balancer is halfway between the 2 marks he made with the piston stop, as it should be. He did not say that crank was at TDC for the picture.

Exactly. I backed out the piston stop and rotated the engine to take that picture. I marked it with a sharpie then I went over it with the white paint so it's kind of sloppy, but it get's the point across.

Yes, I am constantly amazed at how clean this car is underneath. From what I can tell it's spent all it's life in Texas and Ca. There isn't a speck of rust anywhere. Even at 90,000 miles I could shine up the underside and make this trailer queen, but I enjoy driving it too much.

Thanks for everyone's help.

quote Originally posted by Formula350: This picture just shows that the timing mark machined into the balancer is halfway between the 2 marks he made with the piston stop, as it should be. He did not say that crank was at TDC for the picture.

Ummm... okay, glad you understood what was being described.

Anyway, the important thing is that the engine now runs again, and perhaps we've all learned something vital regarding the strength of the magnets in the distributor.