I have a 72 350 olds with automatic and ac. Pretty much all stock, although I bought it from previous owner and am unsure of the cam specs, etc. my issue is that I need to set the timing at 30 degrees or so at idle just to get the car to start. Once running, if I try to back to timing back to 12 degrees or so it will gag and die...even if I try to ramp up the RPMs. It idles fine and seems to run ok, just worried that this is not good for the car. I have been restoring the car for 6 years and am 99% complete. I hate to pull the motor apart for a new cam, timing chain, etc. any thoughts? It burns rich as well, but I will check the choke settings later today. I am running a stock distributor and have the dwell set at 30. Thanks in advance, Joe

 

Don't discount that the balancer may have spun on the hub (or the timing pointer is installed incorrectly). If you put a spark plug stop in #1, and turn the motor over by hand both ways, the balancer mark should end up at equal/opposite distances from the zero mark when the #1 piston meets the stop.

 

Do you have the vacuum advance disconnected and the line plugged? At what RPM are you attempting to set your timing?

 

The car is at the shop getting the exhaust system all welded up, so I can't check the TDC suggestion right now. I am trying set the timing at about 700 with the disributor vac plugged. The timing tab looks installed correctly. The timing mark on the balancer is almost at "noon" when I get it to to idle and run halfway decent.

 

Either the outer ring on the balancer has moved or the balancer is marked incorrectly. Get a piston stop and check the TDC mark on the balancer before doing anything else. Usually more advance makes a car harder to start, so there's obviously something basic that's wrong here.

 

Thanks once again. Will probably check a week from Saturday and report back. if I understand, I will get the cylinder at TDC and if not marked correctly...make the mark here on the harmonic balancer at 0 degrees. I wonder if PO used a balancer from a different year or if that would make a difference, etc.

Have a great new years

 

Yes, scribe a mark at 0 deg with the engine at TDC. Of course, you really should remove the lower pulley and inspect the balancer. It is not uncommon for the rubber between the center and the inertia ring to deteriorate, and sometimes the outer ring can come off completely, usually at speed and with less than desirable results.

The only Olds balancer with the scribe mark in a different place is the 1964 330 balancer, since the timing tab was on the other side of the engine. While not impossible, it is unlikely that this is the case.

 

points or HEI?

Are you watching the engine's vacuum while setting timing and carb adjustments?

Easy to verify the TDC mark... a must to be sure it is not lying.

 

Looks like points. If any cam much bigger than stock was used, might explain why the extra timing is needed. I have ran 58 degrees at idle and 60+ at cruise on a 8 to 1 350 and 403 both with 204/214 cam. Of course that only equaled around 20 base, rest was centrifugal and vacuum advance.

 

Update- I went ahead and replaced the harmonic balancer with a new one. Same effect, but at least that is out of the equation. I still need to run the timing around "noon", but oddly enough I can get it to idle and run pretty good. I forgot to check where the mark on the balancer looked at TDC- sorry. I am running points with the dwell at 30...had an HEI in last month with the same issue; had to remove HEI as it hit my OAI air cleaner. I am guessing PO put in some kind of goofy cam thinking it would be "neat-o". In any event- as long as it seems to be running ok, just leave it as is??? I really hate to replace the cam, etc as the car is 99.5% complete. Thoughts are appreciated. Thanks, joe

 

Sorry, but I still don't understand why people throw money and/or labor at replacing potentially unneeded parts BEFORE performing troubleshooting that costs nothing.

Step one - Check the TDC mark
Step two - THEN figure out what to spend time or money on.

This is troubleshooting 101.

Just sayin'...

 

Joe, unfortunately when guys throw out "It is not uncommon for the rubber between the center and the inertia ring to deteriorate, and sometimes the outer ring can come off completely. Some if not most guys that aren't so mechanically inclined will replace the part just to see if it solves the problem. As this was the case when diagnosing over the interweb .
Jus sayin'

Eric

 

That's also something you can see simply by looking at the balancer. And if the outer ring has spun, verifying TDC will show that. Not my time or money. Oh well.

 

All good advice, it is just that I work 60 plus hours a week, have very few free hours to spend on the car, didn't have anyone to help me "bump it to tdc" and really just wanted to eliminate any concerns. The car is from Tucson and spent many summers in 110 degree heat in a dry climate. The dry ring caused me concern, so I opted to just go ahead and replace the balancer.
Thanks again for all the help, etc.
Joe

 

So, FYI, you can't "bump" it to TDC, since you need to use a piston stop. What you want to do is turn the engine by hand using a breaker bar and socket on the balancer bolt. Turn slowly one way until no. 1 contacts the stop, and mark the balancer at the indicated zero. Turn back the other way and do the same. The true zero mark will be halfway between those two on the balancer.

If you don't want to buy one, a piston stop can be easily made from an old spark plug. Just break out the insulator and weld a nut over the top end of the body (be sure you can still get a socket on the plug hex itself). Alternately, thread the inside of the old plug body for the correct size bolt. Thread a several inch long bolt into the nut or plug body and round the end that would be in the cylinder. The adjustment allows you to back the bolt out, place the piston at about TDC, then thread the bolt in until it stops. Back the piston down then thread the bolt in a couple of turns. It's probably a good idea to have a second nut on the bolt to lock it down before actually checking TDC.

DSC02158.jpg

 

Joe, you are awesome and always give great advice and help out many. Its just sometimes without pics of a bad/good 20+year balancer can leave some guys guessing and not knowing what the difference is. In this case the OP replaced what was suggested could be a bad balancer without properly diagnosing on his end. Maybe in the future pics would be much better than criticism after the fact.
Eric

 

That's a fair comment, however it seems to be a theme across dozens and dozens of threads here (and on other sites) that people will throw money at new parts without fixing the problem, rather than spending an hour or so troubleshooting. Yeah, some if this is just lack of experience, but when a number of people tell someone to look at such-and-such a thing first, it might be a good thing to do.

And no, this is not a specific criticism of any one person, just an observation over years and years of answering questions on various forums (fora?). For example, there's regularly a question from someone whose car won't start. It cranks and cranks but won't fire. Why would someone buy a new battery and starter motor under that condition, especially before checking for spark at the plugs and checking timing to see if the chain has slipped? Yet, the post usually goes on to say "...I've replaced the battery and starter, and it still won't start."

 

Why would they? That's a good question. Its because many have been taken to the cleaners by mechanics over the years. They more than likely don't have the extra money on hand to possibly and I say " Possibly " get screwed over. So they try to fix what they believe to be the problem.
This is an awesome helpful site and as I mentioned you along with many others have been awesome with all your help to everyone no matter what the problem big or small.
Perhaps if someone had some pictures of a good/bad/almost needing replaced balancer that could be incorporated with a reply and kept as future reference for others to view when a question such as this come up. This and other part pics could make this small Oldsmobile community far better than any other forum on the net. Wouldn't that be something. Just my thoughts Joe.
Eric

 

All great advice. Thanks again. This has been a 6 year plus project of weekends and Saturdays. I couldn't have completed it without a lot of sound advice from this site. Thanks to all and have a great New Years!!

 

The point of my example (and I realize this is getting waaaay off topic, so apologies to the OP) was that common sense should tell you that if the engine turns over but won't fire, the starter and battery are fine, so why replace them? The time spent doing that would be better spent finding the real problem.

 

This is probably a dumb question... But are you sure the timing light is hooked the #1 cylinder? Have seen this error before.

 

Yes. But good question!! Sometimes it is the most obvious item.