Hi folks, took my 68 Cutlass S for a ride the other night, pulled over and shut it off to make a quick phone call, started it 5 minutes later and it ran like it dropped a few cylinders. Barely got it back home by revving it in neutral. I left it till the next day, pulled the plugs, checked the resistance on the plug wires, cap, rotor, checked for #1 TDC on compression stroke and started it. It took a bit to get it to stay running but I was able to get it to smooth out and put the timing light on it. It was advanced about 20 degrees from where it was. I try putting it back to where it was and it starts to stall. The weird thing is I put a breaker bar on the crank and it barely has any slack in it - I'd guess less than 1/4" of play in each direction before the rotor stats to to turn. Is that enough to have it jump a tooth - feels pretty tight. The car came with this 455 that was built by a reputable drag racing family so it came to the pervious owner for a great price and it's run great for three years for me since I swapped out the stock 455 that was in the car when he prior owner bought it. The only thing I know about the engine is what was listed when the prior owner bought it:
mild solid flat tappet cam, Harland f=Sharp rockers, forged pistons, 10:1 compression, stock crank, & rods, J-heads (ported?), Torker intake, Morosso Oil pan, professionally built, runs 11.5 @ 115 in a 3300lbs car.

I added a MSD ignition, HEI distributor and Edelbrock AVS2 800 cfm carb.

Any thoughts or suggestions before I start replacing the timing chain would be greatly appreciated - just doesn't seem like enough slack to jump and I don't want to blow the thing up with the timing too far off. I'm just a backyard mechanic trying to do what I can on my own.

Thanks!

 

What brand "HEI" distributor ?

 

Did you disconnect the vacuum advance when performing the timing settings?

 

Check the timing chain this way.
Bar the engine over until the timing mark reaches " 0 " .
Turn the engine backwards slowly until you just detect ignition rotor movement, stop.
The engine shouldn't go back more than 5 degrees until the rotor moves.
Any more than 5 degrees of slack calls for replacement of the timing set .

 

Yes, I did.
Thanks

 

I will give it a try - thanks!

 

It's a Summit Racing SUM-850006
Thanks

 

Pull the plugs, disable the ignition, wire the throttle wide open, and run a compression test. If every cylinder is even but low, it’s possible the chain jumped. I don’t see how that could happen if the chain is tight.

Before getting too deep into the engine, inspect the advance weights in the distributor.

 

I’m leaning towards ignition, unfortunately with MSD you’ve got two “usual suspects,” box and distributor. The basic checks mentioned above should be done, then I would do some diag on distributor. The MSD is a complete mystery to me but I guess that would be the next item to check after distributor, assuming a “physical” problem is not found earlier.

If you find what seems to be chain slop, pull the distributor and make sure the gear’s roll pin didn’t shear.

​​​​​​….

 

x2. Check distributor gear

 

​​​​​​
x3This happened to mine. It was the MSD and gear. I chased everything and replaced chain before I figured out it was the distributor. Live and learn !

 

The situation you described fits the bill for a slipped timing related component, except for the advanced ignition timing.

If what you say is true, it's likely NOT a slipped timing chain/gear, or distributor gear roll pin.

Wouldn't any of those issues cause the ignition timing to be retarded from where it was originally set? The likelihood of those components slipping that far around to have the engine start and have advanced ignition timing would be difficult to imagine.

Keep us posted.

 

I had the roll pin work its way out in 2008, it was together since 1985 the car shut off, would not start Tim

 

Thank you, you are correct, it did retard not advance. Sorry for the mistake! Yesterday I pulled the distributor out and put in a spare that I had (the original that I replaced about a year ago) and as I was hitting the key to get it back to TDC, out of nowhere my starter stopped engaging the flywheel. Unfortunately, I don't have the time to deal with it because I'm going to be away for a couple of weeks. The other distributor looked fine though.....figures, 10 minutes away from firing it up and the starter screws things up.

I will definitely keep you posted - thanks to All!

 

Thank you! As I just wrote to TORO X6, I just swapped distributors but ran into and issue with my starter so I'm on hold for a few weeks till I get back.

Three times, ha - that's crazy. Mine looked normal when I yanked it out yesterday. Did you see anything obvious or find out why it went out of whack?

 

Hello, I've got maybe 4 degrees of slack. I'm sure it's a double roller timing chain - just doesn't seem like enough to jump. We'll see when I'm able to get to it again in about 10 days. I put a spare distributor in, just have to get the starter back in.
Thanks,
Brian

 

If it has 4 degrees or slack, that chain is still pretty tight. I’d start with a compression test, if that’s good I’d pull the distributor for inspection.

 

Might be worth sampling the fuel. Had it been refueled soon before this problem? Accelerator pump squirting well/fuel bowl full?

Good luck!!!

 

I've seen slipped harmonic balancer cause issues.
set #1 TDC on compression stroke and see where you're timing mark is..

 

I am thinking the foreign made HEI distributor.......bad module, bad distributor gear pin or MSD box. Does MSD have a "limp home mode" ? The crankshaft damper wouldn't have made the poor running condition until AFTER it was re-timed. It was running barely before the timing light was used to re-time it.
Then it sounds like the starter solenoid went bad and he doesn't have time to start it again..

 

Thank you and the others who have responded while I've been away. I'm going to try and repair the pinion gear on the ROBBMC starter. I was too lazy to go pick up a 1-1/8 deep socket and crank it by hand so I had my son crank it with the key to get back to TDC. Well, I heard a ding and found the gear in the bottom of the flex plate cover. Cheap setup - only had to 1/4" pins, one one each side of the shaft holding it into the groove on the shaft. Once those let go the gear shot forward and off. So, I'm going to tap and thread the same two holes and put it back together. If the others held then this will. Once I get that back in I'll go through the list, but the distributor does sound like the problem so I'll see if it goes away with the original one and go from there. Thanks again and I'll reply as soon as it's running again.

 

Well, I finally got a new starter installed and my first distributor swap didn't solve the problem because it was the old original one. I swapped the MSD 6AL because I had a spare and that didn't help. My new distributor showed up yesterday and it's back to normal timing again!!! Thanks so much to everyone for your guidance and suggestions!

I don't know what went wrong with that distributor - looks fine to my untrained eye, but it's dead on again - what a relief. I didn't think it could be the timing chain and that distributor is only a year/1,000 miles old. I'm going to see if Summit has any ideas.
Thanks again, Brian