Odd Fire Troubles / Really...?

OK everyone, even though I am very new to the "Forum World" Its pretty obvious that this "odd fire trouble" is probably THE most frequently asked questions there is on early jeep forums. Knowing that I decided to do a fair amount of research on previous posts before I go and make a complete maroon out of myself. I did that, but the latter will probably happen anyway, so here we go-

So: 1969 CJ5, 225 engine is only firing on cylinders 1,3 & 5. After reading older posts I began ruling things out, here is where I am at-

The 225 odd fire block was identified by block casting number (1381628). (archived info, thanks)

I wanted to confirm the crank was odd fire as well so I did a crude indexing of the harmonic balancer and measured the intervals. Yes it would have been easier to pull the pan and look at the crank, but I wanted a visual of the odd fire for my own knowledge and better understanding. I will include this diagram/sequence, it sure helped me and may help someone in the future.

Visually the distributor is a DR odd fire based on the configuration of the drive shaft (one short lobe, two flats, etc.) an elongated tang on the rotor.

I used a test light to verify points are opening at power stroke for 1 - 6 (previous post, thanks). All checked out, however...
I marked where the "spark" will occur for each cylinder in relationship to the distributor cap. It is obvious why 2,4 & 6 are not firing, points are opening in between posts, not even the elongated tang will help.

I was looking on line and ordered a new cap and rotor from Brillmans. I noticed that the location of the #1 post is in a different location in relationship the the points widow. I was hoping this was probably the fix but was disappointed to find that the cap does not work with my distributor base. At this point I am suspect of the distributor.

What an I missing?

 

There were two brands of distrubutors used on the Dauntless; Delco and Prestolite. The caps are not interchangable.
-Donny

 

There are 2 different Delco caps also. I would order all available caps for your distributor, be it prestolite or delco, matching rotors, and trial and error.

 

SHould be easy to ID the Delco vs the Prestolite. If you have a nearby FLAPS (friendly local auto parts store), ask them to order an example of each cap for the Delco and you can compare at the counter, and take the right one. Does not cost them anything but a bit of extra labor.

 

May be obvious but if you're only firing on half the cylinders, I'd guess you are out of phase and the distributor should be shifted by one cylinder. The orientation of the distributor and the plug wires is arbitrary, as long as you have the plug wires in firing order and (on an oddfire V6) you pick one of the three in-phase orders. Some of the three allowed orders probably won't be convenient since that rotation puts the vacuum advance in conflict with some other part of the engine.

What I would try - in the direction where you have the most room to rotate the distributor, move all the wires one post away from that direction. Then rotate the distributor so the rotor is pointing at the same wire as before. Because of the odd spacing, this will mess up the timing, so you may need to static time to get back in the ballpark.

 

What Tim said. You need to make sure when the rotor is pointed to plug 1 it's leading into one of the long flats on the points cam since it's 150 degrees to cylinder 6. When it gets to cylinder 6 it should be leading into short portion of the cam since 5 is only 90s degrees away.

 

Thanks guys. Yes as far as distributors, if I'm not mistaken, the Delco/Remy has the j hook hold downs and the Prestolite has the spring clips for the cap. I definitely have a DR. I am confused why there would be two different caps for the DR with the posts slightly shifted. The base of the distributor has a locating tab and this other cap fit the base but the J hooks were shifted as well and in the wrong location. Would this cap possibly be for an even fire distributor?

I'm with you guys, it sure seems like it's not in sequence, but this is the strange part, Based on the test light on the points and confirming with a probe in each cylinder the points are opening in correct time with the crank. (Tim this was your reply to an older post, "odd firing odd fire") Here is a quick sketch of the distributor shaft. Points open at the start of the short lobe so that #1 seeing (75'/150') leading to #6, the first fire of an odd (90') pair (6-5, 4-3, 2-1). Do I have this right?

I'll try your recommendation today and see what happens.

 

Ok so I tried your recommendation and moved all wires one post "clockwise" and rotated the distributor the opposite direction, vacuum module away from by-pass hose. Would not start.
I had previously determined the coil to be out of specs so I installed a new coil, points and condenser as well while i was at it.
With distributor and wires back in original position it runs again, slightly better but is still not firing on the even bank.

 

I had trouble recently because the coil wire was not pushed down well into the distributor.

 

If one side of an exhaust is blocked, would that cause a bank of cylinders to not fire correctly? I’ve read that before but have no practical knowledge of that sort of thing

 

Scott, I had read your post on that situation and checked it out. Unfortunately it did not solve my problem but it was good input. I do have a new set of wires to put on but am still working with the old ones for now. I am sure a partially blocked exhaust would create issues, I may need to check that if an obvious solution doesn't show up soon, thanks Dale.
What is still can get my head around is that I took that time to manually rotate the engine and mark each cylinders firing position. I did this by using Tim's process he provided to an older post. It did prove that the distributor is working in sync with the crank, but what is odd is that the position of the rotor is not on a post on the 2,4,6 cylinders. I am not sure how this can be possible but I may be over thinking it and overlooking something more obvious.

 

Do you have the correct odd-fire rotor with the wide tip? That's how they get the unevenly spaced spark close enough to the evenly spaced towers on the cap:


Interestingly enough they reversed that on the odd-fire HEI. On those the cap has long leads to get the spark to the posts and the rotor is normal.

 

yes I have the rotor with the wide tip. Do the two pictures that I included at the beginning of the thread show up? I only ask this because they did when I first posted it and then they didn't for a while, not sure what that is all about.
My vac canister is closest to the bypass hose, Fireball is yours towards the front?

 

The pictures do not show up for me. Yes the canister points straight forward.

 

how about this picture?

 

That one works.

 

And where is #1 cylinder in relationship to the front? Do you have access to the points adjust window in this position?

 

This is where the dwell window is. #1 is the post above the dwell window. This Delco cap has the cylinders labeled so that's where Buick intended #1 to be in relation to the distributor.

The dwell window is accessible, but it's close enough to the fan I would not be comfortable adjusting while running.



NOTE: This engine is sitting on a stand in my shop. It was running when it was pulled from the Jeep, but I never heard it run myself. I've got HEI on my '69.

 

I should note in this terrible pictured from the scanned factory manual, the vacuum advance and dwell window point to the right side of the Jeep:



In theory, there are three positions that will work rotating two plugs at a time. In practice the third one doesn't work because the vacuum advance interferes with the valve cover.

 

Thanks for the pics Fireball!
So I am starting to suspect the distributor "body", and here's why, tell me what you think. My current cap is not like your cap. Look at the last picture I posted. Kind of hard to tell but you can see that the #2 post is actually over the window.

I bought a new "odd fire" distributor cap and it is identical to your cap with the #1 post directly above the window. When I put it one my distributor body, located with the notch, it is not able to secure to the body because the clip area is in the wrong spot on the body. This tells me that there is another body type out there that will fit this cap. Could this be the reason the other three posts are not in alignment? Could someone have possibly put the odd fire shaft in an even fire body?

Let me know if it would help and I will post some pics of both caps and how the align on the body when I pull the distributor tomorrow.