Timing Way Off But Don't Know Why

[XinnKoda]

I'm helping my dad restore his 1971 CJ5 with the Dauntless Buick 225 V6 v6. We replaced all the normal stuff you'd get in a tune up kit but we can't get it to start now. It ran rough before so I wanted to check the timing. I noticed the previous owner had all the spark plug wires in the incorrect spots on the dizzy. (I.e. cylinder 6 was actually labeled cylinder 1, etc.). I didn't pay attention to whether it followed a certain pattern so I just plugged them in according to the 165432 firing order. I verified TDC with the #1 piston and the timing marks on the harmonic appeared to be accurate. I set timing to 5 degrees BTC but every time we try to start it, it backfires with a loud bang from the exhaust. I continued advancing the timing until it backfired from both the exhaust and the carb (didn't realize this was possible). I manually pulled the dizzy cap and checked to see that the rotor was pointed at the #1 cylinder and I checked to make sure #1 cylinder is TDC. I double checked my wires and ensured they are all going to the proper cylinders but my gut tells me with it backfiring through both and intake and exhaust, the firing order is incorrect. I think my next step will be to pull all the spark plugs and manually rotate the crank and check all cylinders to verify the firing order is in fact 165432. After that I'm really not sure. It's an odd firing engine if that makes any difference. I've never timed an odd firing engine but I didn't think it would be any different than even firing engines. If anyone has any suggestions on what might be going on it would be appreciated!

 

[tarry99]

So is this Jeep a new to YOU purchase? And how did you determine it to be a Odd or even fired motor? Not unusual for an early Jeep to have a later V6 motor.

Easy for people to confuse the two and therefore get the wrong parts.

Odd fired motors have a different distributor cap and different cam loped distributor than a standard even fired Dauntless Buick 225 V6 .........since you said it ran ruff before......perhaps these parts had already been mixed up.

Hard to explain all of the differences here...........there are plenty of articles on line that should help you distinguish between the two.............but first verify what motor you have and then take each part and verify they are correct.

 

[XinnKoda]

Thanks for the reply. I mentioned that it might be a different engine to my dad. I don't have the Jeep at my house so I haven't been able to spend a lot of time looking at it. Are there casting numbers on the Dauntless Buick 225 V6 to verify that it is in fact the Dauntless Buick 225 V6 ? Also, is it true that an odd fire dizzy cap doesn't have the points evenly spaced? I read that somewhere on this forum but wasn't sure. I think what I'll do is put the old dizzy cap back on and see if there's any difference. Then we'll start going through piece by piece and making sure they are all the parts that are supposed to be in there.

 

[mstar]

Congrats on the '71 that's a great year to have but then i'm partial .
Do you have a Delco or Prestolite distributor.They used both. When you have #1 on TDC is it on the compression stroke. If it is and the plug wires are in order I would suspect a bad timing chain or gears. Hopefully it will be something simple.As far as the odd-fire /even-fire dist.you could look at the cam lobes on dist. Odd -fire will have three pointed lobes and three rounded lobes. As was mentioned there is a lot of info on the net or in print.I refer to V-6 Performance by Pat Ganahl as the bible for Buick v-6 info. mike

 

[mstar]

I failed to mention that a compression test is the very first thing to do. This will rule out some problems if good . My '71 comp. ran 165# all cylinders.mike

 

[Lumpy Grits]

:ww:

Any pictures you can post of the engine and dizzy would be of help to all of us.
LG

 

[Hedgehog]

You could be 180* out. I.E. TDC on the exhaust stroke, happens all the time. Also many odd fire distributer caps are V8 cap with two posts blocked off and when looking inside the cap two contact points will have long arced contact areas. It is easy to put the wrong wire on the wrong post.

Had a buddy with a Dauntless Buick 225 V6 that he upgraded to an HEI ignition. It would run well until going ~55, then it would fall on its face. We looked on line and noticed that plug wiring was inconsistent in the illustrations. Actually two configurations were consistently shown. He had his set up exactly like one of them. We moved the order to the other configuration, essentially one post around the clock, basically from one side of the input plug to the other, retimed it and the thing came alive with extra power all over the power band. I imagine the Odd fire cylinders were originally hitting on the wrong post. Just something to consider along with being 180* out and yes an engine can run horrible with even being out that much.

 

[XinnKoda]

Thank you everyone for all your replies! It has given me much to think about. I didn't realize how different odd fire engines would be to time. After doing some more research I believe that it is in fact the Dauntless Buick 225 V6 V6 and it is using the Delco dizzy. When I set initial timing, I verified cylinder 1 was TDC via screwdriver method but didn't think to check to ensure it was during the compression stroke (on my even firing I6 motor the spark plugs fires on both compression and exhaust stroke so it didn't matter). I also didn't realize how important it was to make sure the wires went to the proper labeled number on the top of the dizzy cap. My dad and I shifted all the wires just once on the dizzy cap (the vacuum advance wouldn't clear the fan otherwise). My next step will be to verify compression stroke and set initial timing and then physically remove the dizzy, rotate the rotor to proper spot, then reinstall the dizzy so that the #1 spark plug wire correlates to the #1 spot on the cap. Again, on my even fire engines I've worked on, it didn't matter which orientation the cap went, just so long as the firing order was correct and the plugs went to the proper spot. I will update everyone on the status of the engine. I'm heading to my dad's tomorrow and hoping to get it all fixed up. Thanks again guys!

 

[Hedgehog]

You won't be able to rotate the rotor cap. It is where it is. The rotor doesn't need to actually point toward the #1 cylinder, it needs to point toward the Plug Wire going to the #1 plug. Mine does not point to #1, but it is a V8 not a Dauntless Buick 225 V6 V6. If your engine was running rough before it's probably something else that needs attention.

 

[tarry99]

Thank you everyone for all your replies! It has given me much to think about. I didn't realize how different odd fire engines would be to time. When I set initial timing, I verified cylinder 1 was TDC via screwdriver method but didn't think to check to ensure it was during the compression stroke (on my even firing I6 motor the spark plugs fires on both compression and exhaust stroke so it didn't matter).

First off Post some Pictures of what you have...........as the HEI Cap will be different vs points...Take the cap off and see if you have 6 similar lobes on the distributor shaft or 3 that are different than the other 3 ...................Timing the engine is basically the same once you have the correct Cap , distributor lope lined up and wires in the correct starting point for #1 cylinder.......

To find TDC #1 pull all your plugs as it will be easier to turn over by hand. If you have a leak down or compression tester threaded adapter with a hose on it thread it into the number 1 cylinder........if not your thumb will work to block off the hole. Slowly turn the motor over and at some point you will feel the pressure within the cylinder trying to push your thumb off ..........hold the pressure and look at the front hub and timing mark and it should be either before or after TDC .........adjust to Zero and let the pressure off. That's within a few degrees of the correct firing position for #1 cylinder. Look at the rotor and where it is pointing...........not only does the rotor have to point to the correct position on the cap you also must have the peaked lobe on the distributor ready to open and close the points...........with the Vacuum advance there is not much room to drop it in correctly with the manifold blocking most of it's rotation.

 

[bzahler]

another easy way to find TDC by your self is to stuff a wad of a paper towel in the sparkplug hole then turn over by hand and it will make a loud pop and blow the paper out when comming up on TDC.

 

[XinnKoda]

Thank you everyone for your help! We got it up and running again today. At some time, the previous owner must have removed the dizzy and placed the rotor in a different position because when we found TDC on the compressor stroke, the rotor was pointed to the rear of the block. This explains why we originally timed it to the exhaust stroke (I should have verified that it was compression and not exhaust stroke). This also explains why the spark plug wires were all shifted a couple places on the dizzy cap. I think the previous owner removed the dizzy and realized he didn't align the rotor where it should have been and then just decided to shift all the spark plug wires in order for it to work properly. So we ended up removing the dizzy, aligning the rotor where it should have been, installing the dizzy, and setting the timing. We set it to 5 BTC (we're using the Delco dizzy). After setting the initial timing by eye sight, she fired right up and we were able to hone in on proper timing very quickly. Thank you everyone for helping out on this. I feel like an idiot for not putting the pieces together sooner. I guess I just assumed since the rotor was in the proper direction when I aligned the timing marks that it was on the compression stroke. Thank you everyone!

 

[Hedgehog]

When installing my HEI dist. I almost did the exact same thing. In my case with the dist essentially backwards there almost was enough room/sweep to properly time the engine. As it turned out the dist. needed to be jumped one gear cog to get the room I needed. So it probably wasn't a mistake, he was likely trying to create room for something. Unfortunately he never told you about it. I'm glad you are up and running now. My buddy replaced his old dist. with an HEI and is VERY pleased with the increase in performance over his old points system.