318 Engine stumble

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Gonna take a few days to get timing tape.
Also.....do you know off hand what diameter the harmonic balancer is. I’d like to get the correct timing tape.

I’m going to do all the tests and see where I end up.






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To start with. I don’t think the module is hooked up backwards.
The picture shows how it’s hooked up. The terminal pins are different sizes. The female side on the plug matches the size of the male side.

The green one is smaller.

I’m headed in the right direction to sorting this out. I definitely didn’t expect it.
 
No matter how it happens;
If the polarity get's reversed on the pick-up, you will be able to time the engine at idle. But as soon as she starts building rpm, the spark will scatter willy nilly,with timing all over the place, and with no rhyme or reason to it, and the engine will run just horrible. You can easily see this with the timing light set to zero/ no advance compensation. I made my boss $1500C one time figuring that out. Longstory. Yes I have seen factory pick-ups coded wrong lol. And not just Honda motorcycles either.
 
glhx said:
View attachment 1715312620

To start with. I don’t think the module is hooked up backwards.
The picture shows how it’s hooked up. The terminal pins are different sizes. The female side on the plug matches the size of the male side.

The green one is smaller.

I’m headed in the right direction to sorting this out. I definitely didn’t expect it.
Click to expand...
I ses what you mean on the terminal sizes. But that does not mean the green and white wires were not swapped when crimped. Or the pick-up is reversed internally (color code on wires backwards like AJ sez). SOMETHING appears to be make the ignition firing way out of sync with the rotor position.

What distributor/HEI kit is this? Is there any documentation with this that would show the pickup colors into the module?

Damper OD is something like 7.2 or 7.3". Some aftermarket ones vary a tenth of an inch or so from stock. If desparate, a big block Chevy tape is pretty close and will give about 1-1.5 degrees error at 40 degrees.
 
Without doing anything yet. I will say. The car runs pretty good except for the transition is choppy and the backfire out the intake when it’s cold. Either way the timing is off and needs to be sorted.

Also....the backfire when starting the car....sometimes.
I almost would have been satisfied with it. Then worked out the choppy transition with more testing.....

Had I not run the piston stop and checked for 0 I would have never noticed it....
I’ll get some pictures tomorrow and see where the ring to reluctor relationship is.

The upper rpm is very smooth past 2400. I’ve had it to 4500 with no load and it’s smooth. Seems to have decent power wide open but it feels like it’s holding back some. So if the module was hooked up backward. The car would run bad in the upper rpm range?
 
glhx said:
So if the module was hooked up backward. The car would run bad in the upper rpm range?
Click to expand...
It probably wouldn't rev at all, and the timing lite would see dropped sparks and erratic timing all over the place.
If you don't know, the Mopar pick-ups are just little signal generators. (They do pretty much exactly what points do with out the hi-rpm bounce, nor the stinking maintenance.And the dwell is maintained better.)
Every time a vane passes by the magnet, it causes a disturbance in it's magnetic field, and the ECU then reads that and tells the coil to fire. But the signal generator creates a signal strength in relation to the coming and going of the vane, with the voltage first rising then falling. If the Ecu is designed to trigger on the rising voltage, then everything is hunky dory. But if the polarity gets reversed so that the ECU is trying to read on the falling side; well you can change the base timing by repositioning the distributor, so it will idle. But as soon as you start increasing the rpm,and the mechanical advance starts coming in, all hell breaks loose, cuz the rotor is waay out of sync. So between those two things occurring simultaneously,it runs pretty crappy off idle. and usually will not rev up very far, and certainly not smoothly. If you are getting a smooth 4500,I'd say your polarity is A-Ok.
I can't speak to the HEI, but I expect it works similarly.
 
Reversed polarity does 2 things:
  • Puts the pulse edge out of sync with the rotor because the physical relationship is now wrong for the assembly
  • The correct polarity pulse edge is quick and sharp and produces a very stable pulse off which to trigger. The wrong polarity pulse edge is generally slow and that creates some ambiguity on the trigger point; the timing gets a bit unstable.
Just trying to figure out your post #94 causes.

Again if you could post your distributor info, that would help.

And if you are suing a dial-back timing light, I would borrow another one and see if that changed the rotor timing situation. Dial-back's are know to show errors with certain ignition types.
 
The distributor is a skip white Hei.

If you look at the reluctor wheel. It’s not pointing at the matching spike. It’s offset.

I have to move the distributor back in timing advance to get it to line up correctly to 0° at TDC......This is making it retarded.

It looks like the weight system is preventing it from moving to 0°.....butnreally it’s the reluctor wheel in the wrong place. ......I’m pretty sure

If you look at the red circles...its the center piece touching the weights that are preventing it from moving to zero....but this is where they belong.

In the picture ....this is sitting at TDC on the timing mark on the harmonic balancer.
I made sure I was on the compression stroke just to be sure it’s in right.
Should the reluctor wheel be pointing at one of the spikes instead of offset?

I do have a moroso 72300 spring kit on hand to tune the curve. It has a center piece, weights, and springs.........i don’t know what that would do if installed.

Maybe it’s the part of the inexpensive distributor or is it me.



Also....reading some of his post is interesting he instructs is to create the problem I have by fixing his own problem of hard starting.
“GM” Style HEI - Aftermarket Weights and Centerplates - Team Camaro Tech

At the end of this guys first post. He has the same or similar distributor.
He says his advance weight center piece was turned upside down making his car hard to start. He then turned it to the correct way.
.......my distributor came the correct way. My center piece that activate the advance weights is correct.

However.......when he did set his correctly. He gave instructions at the end of the post. .....
The instructions were to retard the timing 20° and put it in between the firing. Terminals. Then use the distributor to get it back to zero...
So when he fixed his set up.....he made it the same as mine and instructed others to create the same problem I have.....
As you have told me....
Putting it in between the terminals can make the spark jump to the wrong one.


My spark doesn’t jump to the wrong one at the higher rpms.....but it does when I start the car......making it....sometimes backfire out the intake and sometimes start excellent. Either way we know it’s wrong and I’m thinking it’s manufacturer defect.

36822AC7-237D-44AF-B554-9D301492FF12.jpeg

The center piece is seated and the advance plate is as far back as it will go. I’m thinking the spikes should align and they are clearly offset.
 
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Thanks for the better distributor info; helps a lot. Mmmmm, I'm not at all convinced that the weight and plate motion is the problem. I would not do anything there at this time.

You sound to be on the right track on how to limit the total advance: limit the movement of the center top plate. BTW, that plate moves CW on the shaft as mechanical advance increases. This moves the points on the reluctor CW, and that means they line up with the points on the pickup earlier in the rotation, and that advances the spark.

Please help me understand a few statements better:

glhx said:
If you look at the reluctor wheel. It’s not pointing at the matching spike. It’s offset.
Click to expand...
When the reluctor wheel is offset like you show, is this when the rotor is properly pointing at the spark tower?

glhx said:
I have to move the distributor back in timing advance to get it to line up correctly to 0° at TDC......This is making it retarded.
Click to expand...
In the first sentence, when you say 'it', do you mean getting the rotor lined up at 0* or the time when the spark fires? The meaning of 'it' is not clear to me.

And to be sure we are talking the right terms, you advance the distributor timing by turning the distributor body CCW. If you move the distributor body CCW to make the points line up (as in your pix), you are advancing the timing.

Here is an article that appears to discuss the exact problem you are having with rotor phasing. The OP's 'customers' changed pickups and suddenly the rotor phasing was off by 22*. Please look at the pix near the bottom of the 1st page to see how different pickups have the wires color coded in reverse. Perhaps you got the wrong pickup? These are pretty cheap distributors made in China so anything goes IMHO....
MSD HEI new module timing off big time? - Speed Talk
 
This thing is off

In this picture. We have true TDC. Harmonic balancer is lined up on the compression stroke.

The car wouldn’t even start when it was cold. It didn’t even fire.

The last time I had it here ....the car was warmer. It backfired and wouldn’t run at all.

It’s not showing exactly due to camera angle....but it’s the lower mark.
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In this picture.

This is where the #1 tower on the cap. It’s to the left of TDC
Car backfired like crazy here.

Top of the carb caught fire. I put it out by turning the key over and sucking the flame down.


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As of right now....it’s about 50° and the car doesn’t want to start at all.

I was able to get it to start once at 10° On the light and run for a while with the timing advanced. After that....I tried to set it back to where it would read 0° on the timing light.....so I could see where zero was on the light and mark that to see the difference.

I might have fried the ignition module. I don’t know. I’ve already fried a starter relay messing with this.
 
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Green is where the cap sits With the rotor pointing at the #1 tower. It’s further back from true TDC.......from my experience.....true TDC should be pointing here.
He teeth are offset as shown in the picture above.

Red is where true TDC is when the balancer is lined up. The teeth line up but the car won’t start and when it’s hot it backfires.

Yellow is where I think 0° on the timing light is. The car shut off before I could find it.....but it’s close to that. The timing light read 10° when I was able to start the car. It ran for a few minutes and then started dying. I couldn’t get it restarted. The plugs are black.......

At this point I think the reluctor is out of synch. Maybe you guys will see something I don’t. I’m not very experienced when things go wrong. I usually put the distributor in and it runs fine. Never had a problem like this.

Could it be off a tooth in the gear. We talked about that and decided that the problem would just follow but now that there’s documentation maybe......

B38B72AE-A080-42E8-A12A-36800C238698.jpeg
 
nm9stheham said:
Thanks for the better distributor info; helps a lot. Mmmmm, I'm not at all convinced that the weight and plate motion is the problem. I would not do anything there at this time.

You sound to be on the right track on how to limit the total advance: limit the movement of the center top plate. BTW, that plate moves CW on the shaft as mechanical advance increases. This moves the points on the reluctor CW, and that means they line up with the points on the pickup earlier in the rotation, and that advances the spark.

Please help me understand a few statements better:

When the reluctor wheel is offset like you show, is this when the rotor is properly pointing at the spark tower?

In the first sentence, when you say 'it', do you mean getting the rotor lined up at 0* or the time when the spark fires? The meaning of 'it' is not clear to me.

And to be sure we are talking the right terms, you advance the distributor timing by turning the distributor body CCW. If you move the distributor body CCW to make the points line up (as in your pix), you are advancing the timing.

Here is an article that appears to discuss the exact problem you are having with rotor phasing. The OP's 'customers' changed pickups and suddenly the rotor phasing was off by 22*. Please look at the pix near the bottom of the 1st page to see how different pickups have the wires color coded in reverse. Perhaps you got the wrong pickup? These are pretty cheap distributors made in China so anything goes IMHO....
MSD HEI new module timing off big time? - Speed Talk
Click to expand...

I read the 1st post in that link. That is either close or my exact problem.

I don’t know how far off it is but it is definitely off as you can see.
I read that post but I’m not really sure what they are saying. I don’t understand how the Hei works with the module yet. Crossing the wires.....I don’t know.
This seems like a physical problem.

It looked like he was able to put it back in phase with the vaccum advance but all he did in that post was replace electronic parts. I think the pick up coil.
How would that affect this.

I messed with this all day and it drove me nuts.
 
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Here is what I think I see from your photo's above:
- In the post #110 photo's, where the mark on the damper is at 0 on the timing cover marks (TDC), the reluctor points are lined up with the points on the pickup. This says to me that the physical alignment of the reluctor points is properly sync'd with the timing chain and pistons etc., so the reluctor is not the issue. This should be nominal 0* timing but the actual timing is retarded due to the pickup or it's wires not being right. It is firing at some other angle.....where the reluctor points are not aligned with the pickup's points. It is clear from later posts that the timing is quite retarded with this setting... which says the pickup is not right.
- In the post #111 photo's, it is clear that you have moved the body of the distributor CW, which retards timing even further. This is confirmed by the way the points on the reluctor are CCW relative to the points on the pickup. The timing is very retarded now. But we still do no know where, in the alignment of the reluctor and pickup points the ignition is actually firing.
- In the post #113 photo, showing where you think the pointing is for being around 0* timing, the distributor body has to be turned CCW to get the rotor to point here. This advances this timing and is logical to do so to correct the retarded timing from the pictures in post #110. BUT, the reluctor and pickup points cannot be aligned with this setting, based on the other pictures. So that says the pickup is the culprit.

Refer to the later photo in the last thread I linked, that shows the different wiring polarities for this pickup type. Next step ought to be to try a different polarity pickup.

AND be aware that this distributor, when configured to use with an external MSD ignition box, uses the reverse polarity to trigger the MSD module versus the polarity for the HEI module. So your distributor may very well have a pickup with polarity set up for an MSD box...which would be wrong for your HEI module. This is a cheap distributor from China.... so don't 100% count on it being correctly assembled out of the box.
 
nm9stheham said:
Here is what I think I see from your photo's above:
- In the post #110 photo's, where the mark on the damper is at 0 on the timing cover marks (TDC), the reluctor points are lined up with the points on the pickup. This says to me that the physical alignment of the reluctor points is properly sync'd with the timing chain and pistons etc., so the reluctor is not the issue. This should be nominal 0* timing but the actual timing is retarded due to the pickup or it's wires not being right. It is firing at some other angle.....where the reluctor points are not aligned with the pickup's points. It is clear from later posts that the timing is quite retarded with this setting... which says the pickup is not right.
- In the post #111 photo's, it is clear that you have moved the body of the distributor CW, which retards timing even further. This is confirmed by the way the points on the reluctor are CCW relative to the points on the pickup. The timing is very retarded now. But we still do no know where, in the alignment of the reluctor and pickup points the ignition is actually firing.
- In the post #113 photo, showing where you think the pointing is for being around 0* timing, the distributor body has to be turned CCW to get the rotor to point here. This advances this timing and is logical to do so to correct the retarded timing from the pictures in post #110. BUT, the reluctor and pickup points cannot be aligned with this setting, based on the other pictures. So that says the pickup is the culprit.

Refer to the later photo in the last thread I linked, that shows the different wiring polarities for this pickup type. Next step ought to be to try a different polarity pickup.

AND be aware that this distributor, when configured to use with an external MSD ignition box, uses the reverse polarity to trigger the MSD module versus the polarity for the HEI module. So your distributor may very well have a pickup with polarity set up for an MSD box...which would be wrong for your HEI module. This is a cheap distributor from China.... so don't 100% count on it being correctly assembled out of the box.
Click to expand...

The is a speedmster pce376.1051
How does the engine run clockwise with reverse polarity.....
How do I know which pick up coils would have a different polarity in the aftermarket application? I know gm have a yellow wire.
Should I just get a new pick up coil from autozone and try it?

If I move my drive gear back one tooth. That would change the phase position?
I just don’t know how much and as soon as you take those things out they don’t want to go back in. Unless there is some trick to it. I spent probably two hours playing with that when I installed it.
It seems like it would at least move true TDC CCW and closer to the #1.

I only changed it because it was supposed to be a stronger milodon shaft.......I can post a picture of it’s position, but as before I don’t think that’s the problem here. Could this be two problems? I don’t want to get off on the wrong track by messing with that if it will not help.

I wonder.......what if I put the Chrysler distributor.....the worn out points one back in to see where it’s poinitng. It should be pointing at the #1 at TDC. It should be in phase.

Also..if I use a vaccum pump to pump up the advance can. Will that put it back in phase for testing?
 
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So Speedmaster, not Skip White? Well that looks more like what you show. Still Chinese made....

Moving the distributor a tooth will not change anything. You will just end up rotating the body of the distributor to match how much the shaft rotated and end up in the same situation.

You really don't need to understand why the reverse polarity throws this firing location off, just that it DOES. Look at this link again:
MSD HEI new module timing off big time? - Speed Talk

Go down and look at the picture with the 3 pickup coils shown side by side. Take yours out, and compare to to the pix to see which you have and then go, and buy the one with the opposite wire colors.

And yes I think you have 2 or more problems going on.
 
Need help with rotor phasing

This guy had the exact same problem. Solved it with an adjustable rotor

His #1 was showing at 40° btdc. Mine is about the same.
I think each spike is 45° apart.

The ready to run he was using is a Chinese distributor.
The msd, skip white, speed master are the same thing with different price tags. It is a cheap distributor that’s for sure. I paid $70 for it.

I will do some of the stuff as said above today and see where that gets me.
 
That is one way to solve the rotor phasing. Buuuut...

If the polarity is reversed, you run the chance of having erratic triggering of the HEI module, with spark timing jumping around, even if the rotor phasing is fixed.

The old points distributor is tempting, but certainly not without installing new points and condensor. I looked at the pix you posted of that and still cannot tell if the nubs on the shaft that push on the points' rubbing block are worn down or not... And certainly the wear on internal bushings is unknown.
 
Well. I figured out how to rephase it easily.
The bad part is I broke a tooth off the star wheel.
If I had to repahse a new one I wouldn’t break it.

I will say that I wasn’t careful and basically decided to sacrifice it.
If I can get a star wheel for it I can press a new on back on. Not a big deal.....the star wheel is in phase now....it’s just in phase broken.....

The points distribitor is done. The advance is locked up, the bearings are hard and the rubbing block is worn down. I never could get it to even close to spec. Pretty sure the. I want to say the dwell was 42......and was supposed to be 32
At .017 open. That’s off the top of my head. I have it written down somewhere. It’s an original 1968 points style.

What I do have is a electronic Chrysler distributor that came with the engine.
It worked when we took it out of the old car.
When I tried to put it back on the 318. It wouldn’t fire. I also didn’t know how to limit the timing on it. It’s smog era so the timing will smog era and meant for emissions. welding up the slots is what is usually done on those....and then file them down to where you want them....but even that distributor is from 1976 and is probably worn some.

This Chevy distribitor.....I do like it. It was clean as very easy to hook up. Very easy to tune and put out a much hotter spark. The difference was noticeable. Aside from poor design....I do like the quality of it. I will say that the advance plate could use a spot weld. I was able to repahse it using that. Because it was like a crimp connection. I just loosened it. It could easily be recrimped in a vice or with a hammer. It should be welded or brazed. Even if I got a new one....how can I be sure that it’s not going to be out of phase or the wrong polarity..
I need something I can tune.


On the clocking of the oil pump shaft. It’s not a big deal but it was installed a tooth off. I put the points distribitor back in just to test where it used to be and it showed up one tooth to the left. I will be correcting that just for the heck of it.
 
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Tug gently on the weights and pull them outward, to simulate the centrifugal force in normal operation. That should turn the part of the shaft that supports the reluctor in a CW direction, if it a correct rotation for this engine.
 
It does pull the weights clockwise....and counter clockwise. I was wondering. The timing did advance as it should somthats not even a problem.
All that is problematic is.....it being out of phase.....and if the polarity is wrong.

Is there any way to make this thing be any sort of quality? Like putting Delco or msd parts in it to be sure of the polarity.

I started reading about the pick up coils. The whole thing is sort of confusing. I still don’t completely understand it....

What I don’t understand.....is that the pick up coil is a fixed device. Except the vaccum advance pull. If I bolt another pick up coil in there. It’s going to have the teeth in the same location. Even if I put a Delco coil in there.....Any 3 of those coils in that picture will sit in the exact same spot and be out of phase regardless of polarity. If this is the case. Then how would polarity have caused this fixed location problem. ......this car ran fine in the upper rpm. It ran well at 13° advanced.....never did backfire there when it was warm.
....it did when it was cold. I thought the choke adjustment would sort that out.. now I’m not so sure. I mean.....I could have relocated the vaccum advance and put it back In phase. Just put a bolt through the bottom of the distribitor and move it back some.


Even messed up. This distributor ran the car better than any I’ve had in there.....which was only the worn points but that’s not saying much.

Then you have polarity. For clockwise and CCW. This is a Chinese knock off. For all I know it is supposed to have a yellow plug end and they just threw a black one on there because that’s all they had. We know they wouldn’t care. I can get a compass and check it.....or just buy stuff that I know is clockwise and the phase is correct

If I were to get another one of these and put better parts in it....would it work. The only value to me is that it fits a Chrysler product and cleans up the engine bay. Everything is right there...
If I could afford to put an e curve msd on it I would. I like that I can limit it with a roll pin and take off the springs in ten seconds and tune it to where I want it.

Is there a way to make it better or should I just wait and get something else down the line? What would you recommend?
 
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The polarity is for what the particular HEI module is designed to work with. The polarity refers to the the + or - direction of the electrical signal from the pickup. Yes, the pickup will line up exactly the same but the electrical polarity of the signal to the HEI module will be the opposite. This will make the HEI module trigger at a different rotation angle. The signal waveform is discussed in the link in post #109.

I've stated what I would do in post #118: Look at the picture with the 3 pickup coils shown side by side. Take yours out, and compare to the pix to see which you have, and then go and buy the one with the opposite wire color. LOOK at the wire colors in that pix. Or cut your pickup wires, solder them reversed, and heatshrink-protect the solder joints.

Buying another distributor is OK too.
 
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