A bit of a long story. 1969 350/300hp. The engine was in bad shape. Had it completely rebuilt. The heads were warped and could not be milled anymore so they put on rebuilt 300hp used heads. When I picked it up from the mechanic it was running fine. Got it home and noticed the distributor was 180 degrees out. Plug wires were put on in this firing order: 65721843
I don't know why he did that and don't want to ask. I wasn't real impressed with his abilites after that.

I reversed it back 180 degrees and put plug wires on in correct firing order.
Ever since that I have been having trouble starting it and keeping it running.
I figured I had it off by a gear on the distributor so I have played with it until it 'seemed' perfect. I actually had it running the other day and was able to set the timing dead on. Idled great. But when I rev it, it back fires thru the carb. I have bought a pertronix coil and ignitor point replacement set and have switched back and forth between it and regular points just to make sure the problem is not there. I had it running Saturday and without changing a thing I could not get it to start Sunday. I tracked it down to a bad coil wire so I went out and bought a cheap set of plug wires and replaced everything. It started and ran but then it would not start later that day. It just don't make no sense!

The distributor has quite a bit of end play in it which I can see how it could cause possible backfiring but should'nt it at least start reliably everytime. I bought a new Holley carb(4160) to replace the original and the problem remains.

Question: I know how to determine TDC but how do you know if the rotor is pointing in the correct position? I am just going by sight judging where the number one cylinder should be located on the distributor. Is there a sure fire, can't miss way to determine that the distributor is not off by one gear?

 

First off, was the car running properly when you picked it up? If so, why do you think the distributor was off 180 degrees? When the #1 piston is at the top of its stroke (after the intake valve opens), the rotor should be near the #1 terminal on the distributor cap.

As far as having the distributor a tooth off, I have done that before (actually I had on two teeth off). The way that I finally realized that it was a tooth off was because I could hold the cap all the one to one side and the engine would act like it wanted to start, but could not fire up. I then pulled the distributor and rotated it one tooth in that direction. Then, it would run if I had it turned all the way to one side. Finally, I pulled the distributor and rotated it one more tooth in that direction. It fired right up.

 

dgruenke, thanks for replying.
I have tried that and did get it to run and that is where I am at now. I just quadrillion checked the TDC and rotor placement and it appears correct. The rotor is, looking from the front of the engine, pointing a degree to your left. The timing mark is at 0 degrees. I 'gently' placed a scewdriver in the number one cylinder and can feel the top of the piston; level with the plug hole.

Regarding the 180 degree off, the firing order of the plug wires told me that.

What is odd is it acts like it is getting no fire at all. Just cranks and cranks. I pulled #1 and 7 plugs and verified spark. I verified spark at the coil wire and points but the engine does not sound like it is firing at all. Occasionally I get a fire but rarely.

I have a short in the courtesy lamp circuit but the fuse is pulled. Could that somehow effect the spark?

I am going to try, one more time, moving the distributor a gear or two and see if I can get any difference out of it.

I am about to haul it down to someone but I hate admitting defeat. Can anyone out there recommend a good mechanic who knows these old school engines in the North Dallas, Texas area?

 

If you are getting spark to the plugs, it is either timing or fuel. I would probably rule out fuel if it ran fine before you pulled the distributor.

Are you sure that you have the plug wires on correct? I am just stumped as to why the car would run fine if the wires were initially run in the wrong order.

 

You need to make sure you are on a compression stroke and not an exhaust when your timing mark comes up. I do not think it would run if 180 degrees off in the first place and IF the wires were wrong you could of probably put the wires right and it would of ran right. Hold your finger over #1 hole and spin the motor till the mark is coming up and see if it blows your finger off. IF not you are 180 off.

 

If you it drove home from the mechanic shop fine then your distributor wasn't off 180 degrees. I'm assuming you pulled your distributor cap off and saw the rotor was pointing at 6 - so you counted 65721843, I'm thinking this is correct. Since the timing order is 1-8-4-3-6-5-7-2 (clockwise), starting at six and ending your count 1 before 6 would yield your result.

Put #1 at TDC on compression stroke (when you feel air blowing out of the hole), pull your cap and see what you got. Then start #1 from where the rotor is pointing at your cap. If you don't like where it's at turn the oil pump shaft. Make sure it's really close or you'll get the tooth or teeth off syndrome I just recently dealt with on my new motor. GL.

 

 

Thanks guys.

I am going to start from scratch again following your suggestions.

Just for clarification, he had it where the #6 cylinder was in the #1 rotor position and so on around, as in 65721843 ending with the #3 cylinder being in the #2 rotor position. The correct #1 cylinder rotor position, as you know, is at the front of the distributor a degree to the left looking from the front of the engine. He had the firing order transposed so that it would run in 180 out.

 

If it runs but then backfires when you rev it, the firing order is off, put it back to where it was when you picked it up and go from there. Mine backfired when I put the new distributor and it turned out to be #6 & #7 wire were crossed. If it ran fine going home then I think you tried to fix something that was not broken.

 

If I may ask, Is this the stock "Manual Tach" Distributor that was used in 1969?
If so, what position is the cable drive located at for the tachometer?

 

There is a difference between the distributor being 180* off and the timing being 180* off. The #1 wire should be near 10 o'clock when looking down at. Not that it has to be, but that is the position the factory put it in and the way 99.9% of mechanics put it in. Precut ignition wire are desiged for it that way.
What is important is that the rotor be pointing at the #1 tower on the cap when the piston is at TDC on the compression stroke. Whether the #1 tower is at 10 o'clock, 4 o'clock, or 6 o'clock. The other important thing is to have the vacuum advance somewhere behind the carburator pointing in the 2-3 o'clock position so that it allows for ample adjustment of the ignition timing.
When timing is 'off by a tooth', it means the vacuum canister is hitting the intake or a bracket and the timing cannot not be set because of it.

 

OK, here's the latest in this sad saga.

This morning I hooked up a compression tester to the number one cylinder. I turned the engine until I had compression and the timing mark was lining up with 0*

The rotor was off from where the manual says should be the *1 firing position. Probably because I have been playing with it moving a few teeth to see if that was the issue.

I pulled the distributor and set the rotor to where the manual shows the #1 firing position to be on the rotor. The rotor cap still had the wires on it so I checked to make sure the rotor was indeed pointing to the the #1 cylinder spark plug wire.

The vacuum canister is indeed in the 2-3 oclock position. The tach drive is approx. in the 8-9 oclock position (This is all if I were standing at the rear of the engine looking forward.)

Checked and traced each cable from rotor to plug and they match up in the correct firing order(1-8-4-3-6-5-7-2 )

Tried to start it and it works like it is going to start, I get some firing but no running.
I adjust the the distributor a little to get it close to timing and then I get no fire at all.
I move it back and still no firing. (As if there were a loose wire but I checked the wire from the dist. points to the coil and it is tight and checked all plug wires and they are tight.

From what you are saying, theoretically, instead of re-aligning the distributor each time, I can just move the plug wires around the clock until I get fire as long as I keep it in the correct firing order. Right?

Could a coil act up like this? This is a new Pertronix coil, but if it were not right, could it fire sometimes then not others? Or be giving too weak a spark? The spark I am seeing is blue at the points and plugs. I have a good multi-tester but it won't test over 600 volts.

 

You can play musical chairs with the wires or pull the distributor and turn the rotor. Either way will work but it is preferred to have the #1 tower in a certain position where it is normally seen. Moving the wires clockwise would accomplish the same thing as turning the distributor counter clockwise.

From the way it sounds, you had the #1 piston at TDC on the compression stroke. For sake of discussion, it doesn't really matter which cylinder is used to do this. You could choose #7 pistion to be at TDC on the compression stroke as long as the rotor was facing the #7 tower on the cap. As a general rule #1 is used because the timing mark on the balancer is scribed for #1.

Anyway, back to the issue. Are you 100% sure you have the cap on correctly. There should be a notch in the distributor that corresponds to the cap. The cap should drop in only at that point. At all other positions the cap will be cocked(can I say that?). I don't know how much you cranked the engine or how much fuel you pumped into the engine. There is a possibility of it being flooded.

 

Is it getting GAS?? Try and pour some gas down the carb hole and then try to start it. If you have a big cam you may not be getting enough gas to it to start

 

GPD the only thing I know to suggest is to move all your plug wires clockwise one post or counterclockwise one post and see if it fires.

It maybe easier for you to play musical distributor slots than musical plug posts , your choice really. I was having the same exact problem and moving all my plugs counterclockwise 1 post helped.

You might want to check for flooding too as mandm1200 suggested. Make sure your oil isn't filled with gas.

 

Thanks for the help everyone. At my son's request I tried putting it back just as received from the mechanic and it tries to start but wont. I am taking it back to him since the rebuild is under warranty and let him figure it out.

Just a side note, it does have a mild cam that was put in during the rebuild, and an Edelbrock Performer intake and brand new Holley 4160 that replaced the old one. I didn't touch the carb but only to make sure the metering jets were 1 1/2 turns out as the default from the factory(This was after trying to get it to start). I even tried some starting ether but it makes no difference.

You might want to know that this was the second new holley as the first one leaked gas at the primary bowl and carb body. The bolts were not tight at all. Even after tightening the bolts it still seeped gas at the primary and body. I contacted Holley support just to see what they would say and after three days they replied telling me I must have gotten something clogged in the jets and started telling me how to take it apart and fix it. Needless to say, I just took it back to Autozone and swapped for another.

I'll reply back to this post when we get it figured out just so if someone else runs into this issue it may be of some help. I am positive at this point it is something really stupid I have done or have not done and I just can't see it.

 

Typically something like that is not covered under warranty. You may have a point in your favor that he did not have the wires in the correct position to begin with.
I wouldn't be surprised if he pulls the distributor to reset it and gets it fired up in less than 10 minutes. Depending on the garage they may allow you to be there to see what they do. A great learning experience if allowed and a good way to pick up a few tips.

 

Problem solved!

Thanks to TRACCDOG, who graciously came over to the house, we got it running. A couple of things were wrong.

1. The timing was off by a tooth
2. The points were bad.
3. We replaced the plugs. After so much cranking the plugs had become fouled.

If you live in the Dallas area and need a GREAT C3 mechanic, get hold of TRACCDOG.
Very reasonable charge to do the work and really nice guy who goes above and beyond.

 

First of all, it doesn't matter if the distributor is off by a tooth or not - if you can verify and set the timing to spec with a timing light, the timing is right - being off a tooth will only "clock" the distributor a little off in the engine compartment, and that's cosmetic only. On some engines (mostly C2's), being off a tooth will physically limit where you can set the timing, because the distributor vacuum can will hit the back of the intake as you try to advance the timing. That's the only case where "being off a tooth" makes any difference.

For step-by-step instructions on how to correctly set up and drop in the distribuor (with photos), just drop me an e-mail for my "How to Install Distributor" tech paper. It will take you through the whole process, including how to correctly set timing.
V8FastCars@msn.com
Lars

 

I have been saying the same thing over and over again. The distrubtor can not be off a tooth since it can be rotated. It's the vacuum can that can cause interference not allowing the distributor to be positioned to get the timing where it belongs.
However; there are some reasons to do it a certain way. In looking down on the distributor cap, it is customary to see the #1 plug at about the 11 o'clock position. Most people will assume that position to be the #1 plug when doing any diagnosing and will save them the time of tracing the wires. Another reason to have the distributor in this position is that some ignition wires are cut to a specfic length. It is possible that having the distributor way off, that some wires may be an inch or so short.
The only way to set timiing is with a timing light. If the timing marks are correct, pulling the distributor and adjusting one tooth will absolutely make no difference in engine performance. I've seen several threads where this was done and the poster saying how much better the car ran. I just assumed they did not use a timing light either before or after making the change. It's also safe to assume that this type of person should not be doing their own work or they should invest in some tools.