442Harv

A couple months ago I posted about my sons 68 W30, not running good. The one problem we were not fix, and still haven't is the timing shows about 50-60degrees advance. I know this can't be, as the car would probably not be able to turn over. At the time we did compression test,OK, checked for top dead center, make sure chain didn't jump, checked the balance r, for slipping. My son does not have much time to work on the car so just let it set, It has a Protronix in it. I thought maybe that was a problem, as it was in for quit awhile, but not many miles as he hardly drives the car. One more thing we did a complete overhaul, years ago., but like I said not driven much. I bought him a M&H electric ignition for Christmas. Yesterday we worked on the car. Took the distributor out. One of the magnet pickup fell off. We thought that was probably the problem. Put it back together, started it. Now runs on 8 not 7, but not very good. Timing stills show 50-60. Here's is my new question. We timed it by sound a vacuum, but when we hooked the vacuum back up to the distributor, it ran worse hooked up, than without. We did drive it and ran petty good, but I know it is not correct. I told him I thing it would be worth while to take timing cover off and check chain? Anyone have any ideas?

oldcutlass

Which Pertronix unit are you using? Timing by vacuum and sound is not the best way, that is what timing lights are for. How much mechanical advance does your distributor have built in? This is found by checking your timing (without the vac advance connected) at the rpm where the timing stops advancing and noting at what rpm it stops and what the timing is (total timing). Then subtract what your initial timing is without vacuum advance from the total timing and that will tell you how much mechanical advance is built into your distributor. What is the initial timing set to without vac advance connected and what is it with? Then what is your total with vacuum advance at the rpm in which the timing stops advancing?

442Harv

What most guys are not understanding, i, I'm using a dial back timing light, with vacuum line to distributor disconnected, and plugged, and the timing shows 60degree advance. Is not a light problem as use two lights., and he also has a timing tape on it, and it reads the same. I know how to time it the right way, but what I'm trying to say is if I retard it, the lowest I can get it is about 40 degree, and it runs bad, and can't keep it running. When I the car was running good, It had 36 degrees total, all in about 26 -2800 RPM, car ran in the low 14s. Trying to find out why it show 50-60 degree?

oldcutlass

The only thing I can think of is the advance plate or the vacuum advance cannister is sticking.

sysmg

If it appears to be running good, it can't be at 50-60 degrees advanced. That would mean that most of the fuel charge would be burnt before the engine reached top dead center. Something in your setup, measurement or your process is wrong.

NTXOlds

You sound like you know what you are doing, so please do not take this the wrong way. Using Occam's Razor, the simplest answer is usually the best or the correct one, but are you certain that you are checking the timing using the correct cylinder?

The #1 cylinder on a Ford V8 is the #2 on an Oldsmobile V8, and this cylinder would fire about 45 degrees before the #1 which would be in the range of what you are seeing.

Let's at least eliminate this as a possibility.

Sugar Bear

X2^^^ and double check the firing order. Even if you're at #1 if the wrong wire is there it will be off. Any chance of arcing inside the distributor cap?

sysmg

The #1 cylinder is on the drivers side closest to the radiator.

allyolds68

When I installed Crane's version of Pertronix I had the same problem. I had to run a stupid amount of initial timing to get it to run. I was happy when it failed completely and I went back to points

sysmg

I disagree with most of the suggestions to fix/replace something. If it's running good, its more likely you are having challenges measuring the timing correctly. Once you get that straightened out you can fine tune the timing.

If you had the wrong firing order it would not be running good. If you ignition was bad it would not be running good. If your advance plate was jammed or the vacuum advance was real messed up it would not be running good.

Dynoking

Could the distributor be installed one tooth off?

cutlassefi

Dist being one tooth off wouldn’t matter, it’s still showing 50-60*.
OP, when you say you checked for a jumped chain, how was that done?

442Harv

Brought number one up to TDC, checked the timing mark, was correct and looking were the distributor cap was pointing. All seemed good to me. Also this engine, was completely overhauled, it was years ago, but it has low mileage on it, and we put a good brand chain in at the time. Don't remember the name. I also seemed like I never heard much problem with this Olds motor jumping a chain? But maybe. I also think It would not run good if it did, correct?

cutlassefi

But you can move the dist to compensate for any other change so the checking you did is somewhat irrelevant.
However it will run one tooth off, but I’ve never seen them actually “jump” on their own.

matt69olds

Double check the timing with a different timing light. Make absolutely sure the firing order is correct.

Pull the plugs, disable the ignition. Do a compression test. If the readings are equal but lower than expected, the timing chain might be a tooth off. What are the odds a timing set with multiple key ways was installed? It’s real easy to get the key ways mixed up, resulting in cam toming off.

442Harv

Like I have said. We have done all the things that everyone has posted. Different timing light, it also has a timing tape. Did compression test checked firing order, checked for TDC. checked vac moduel,We put this engine together, so know we put the chain on correct. Like I said this car is not driven often, but he has been driving it for about 20 years and was running great. He took it to the track a couple times, and car ran in the low 14s, which I think is petty good for this car. I just starting doing this lately.

Yacht Machanic

I had similar problem on a 1967 Cutlass 330. Had Harmonic Balancer rebuilt, Rebuilder set it up as a 350 with 0 degrees lined up with key way on crank shaft . What I'm getting at is the outside part of Harmonic balancer could have rotated on center piece. I could not get motor to stay running when trying to set timing to Specs. So I reverted to my childhood when nobody I new had a timing light, Kept advancing it till it would kick back when starting.