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We've run this one round the block a million times on the commando board and we're looking for fresh ideas (ive' posted this here before, but don't get cranky, my Jeepster is shorter than an 8 :)
We've got a 225 odd-fire V6 and 4 of us get great performance at 25-35 degrees BTDC and can't even start it at 8, which is where it's supposed to be. Everything checks out: degree the cam, double check the marks on the balancer, triple check the part numbers for the rotor, cap and firing order.
Timing is 1-6-5-4-3-2. My block is .030" over, with a mild cam and a low restriction exhaust system. It fires IMEDIATELY. If it were a backpressure or vaccuum issue, it would at least try to start at 5-8 degrees.
I don't want to kick a dead horse, but there are more brains and experience here than most places and I'm hoping someone will have heard of this in the past.
Believe me, the basics have been checked by many, independant guys in our club and we're stumped.
(BTW, if you combine vaccuum and mechanical advance, this thing is running with great power at a total of 70 degrees of advance!! It's a little weak at the low end, but that might be 3.31:1 ratio with 30" meat)
Thanks in advance,
Michael
[email protected] (remove the X)

1967 Commando SW
A labor of love, (mostly labor)
 
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Are the balancer and timing cover off of the same year and model engine? Did you use a piston stop to find true TDC? You can make one out of an old spark plug by breaking out the ceramic, threading the inside for a piece of threaded rod, screw in the plug body and then the threaded rod so the piston stops a few degrees from TDC, mark it, then turn it the opposite way until it stops and mark it again. Split the difference, and you have true TDC. If your dampner or timing marks are off, try to get a timing tape for the dampner or make a new pointer. The old 2.8 V6 XJs are notoriously famous for slipped outer dampner rings, this is how I verify them.
Hope this helps, good luck!

P.S.: You did try a different timing light, didn't you?

 

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so what you are saying is it runs good, but its at 37 degrees.. mm...i dont see aproblem here.. lol..
i dont have anything to add but my insight.. the above post covered it great..good luck.. but hell if it runs good.. dont f*%@ with it.. lol

survival is instinct, but living takes guts
 

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Thats pretty high!! I have to run my 304 wacky cam, 4barrel, headers higher also. Likes to run about 22 degrees at idle and way up there at 3k rpm's. The ballancer slipping idea is a good thought. I think I'll take a look at mine also to see if it maybe slipped.

 

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26 to about 36 degrees is 'Normal' for TOTAL advance figures.
6 to 12 degrees is 'Normal' for IN ITAL advance figures.
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If you actually were 70 crankshaft degrees out, the distributor would be firing the next cylinder, which are only 90 crankshaft degrees apart.
That would mean the timing indicators are lying (very possible), or you have the distributor in two teeth retarded (also possible), or there is some mystery problem your people have missed, and so have we...
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The original poster is talking about initial advance, if I get the posting correctly.

To chase this ghost, you are going to have to verify a few things...

1. Use a piston stop, like what was suggested before, and find TDC on #1.
DO NOT USE THE STARTER TO TURN THE ENGINE OVER WITH THE PISTON STOP IN !! Turn it by hand with all the plugs out.
(Take the valve cover off of the #1 bank and verify this. You CAN NOT guess here, so don't cut corners.)

2. Verify the timing mark on the harmonic balancer and the timing tab agree.
(If they don't agree with the mechanical TDC you know to be true, get new parts that do agree. It's usually a mix & match balancer and cover, or a slipped outer ring on the balancer)

3. Mark the location of the #1 plug wire tower on the distributor housing.
Flip the distributor cap, and see if the rotor is pointing at the #1 plug wire tower mark.

There should be a picture or diagram in your rebuild manual that shows where the vacuum advance is supposed to be pointing when the distributor is properly installed, Find it....
If either of these things is wrong, you will have to pull the distributor and relocate it.
(If the mechanical piston stop, and the balancer/ timing pointer agree, it's probably distributor install problem.)

Check your firing order, and the location of the #1 cylinder again...
If your plug wires are off, by even one hole, you are screwing things up, and this happens more than you think...

FACTS.
One Half of amateur engine builders either have the plug wire firing order off, the distributor in wrong, or a mix and match timing cover and balancer when they complain of 'Timing Problems'...

On a 13 tooth distributor drive gear, each tooth is worth 55 degrees crank timing.

The #1 cylinder is the farthest forward on any common engine. Look at your engine from over a fender, and you will notice that one bank of cylinders is farther forward than the other bank.
The forward most cylinder is #1, and the one you should time from.

The starting point for the firing order on the cap, and the 'Clock Position' or location of the housing relative to the engine are not suggestions, they are mandatory for proper operation of the ignition system. Get the housing turned around where it's supposed to be, if it's not already...

Mark the location of your distributor cap #1 plug tower on the distributor housing, and leave the rotor on the distributor with the cap removed when you install.
The rotor and mark will make install much easier.

Keep the vacuum advance where it's supposed to be when installing. Just turn the rotor to get the correct tooth placement.

Remember, the oil pump drive may not line up, and may hold the distributor as much as 1/2" up from it's seat. Turn the engine over, BY HAND, two full revolutions, and come back to the VERIFIED TDC mark. The distributor should have seated.
Make sure the vacuum advance is in the correct position, and then check the rotor nose alignment with the black mark. If it lines up within a 1/4" either way, you are correct.
If it is more than 1/4" off, pull the distributor up and try again until you get it correct.

If the distributor was disassembled, there is a 50/50 chance your gear was installed wrong when it was put back together.
This affects rotor phasing, and will put the rotor around 28 crank degrees out.
There should be a dimple in the drive gear. Align that with the rotor nose for correct gear to shaft alignment.

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?
 
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