Timing issue?

[bobs69z]

My 69 Z with original engine starts hard after it warms up.  It really lugs battery on restarts and barely turns over.  It has a brand new battery.  Im thinking its timing.  Put timing light on and cant get timing line to match tab.  Its on top.  If I degree timing light 25 degree it brings it in.  Ive never had to do that before.  Am I doing something wrong?  Also reset points to 30.  Is that correct?  Car idles around 1100 to 1000.  Im an old big block guy.  Never messed much with a 302, but heard they can be contrary.  The car runs great, doesn't stumble or blow black smoke.  Thanks for any help.  Bob

[jdv69z]

Maybe too far advanced? Mine is set at about 12 degrees BTDC. That's static only. Not vacuum or centrifugal.

[mikefam]

Are you disabling the vacuum advance by removing the vacuum hose from the distributor and plugging it up?

[mikefam]

Have you removed the distributor since you last put a timing light on the engine? If no then I would take the distributor cap off and inspect the mechanical advance mechanism and springs.

[bobs69z]

I didn't do initial timing.  Just purchased car recently. The engine has been rebuilt with only test miles.   I did plug vacuum when checking timing.  Might have to pull distributor and start over.  I Cant turn timing back to get it on timing line.  Engines dies.

[BillOhio]

If you are trying to get it to the 0 line it will die.
I would only pull it if the vac advance can is hitting something. Do you have a timing tape on the dampner?? 

[mikefam]

Turn the idle up so that it stays running and set the timing to whatever the specs are for your engine. Then adjust the idle for about 550 rpm in drive (if automatic trans) or about 800 - 1000 rpm in neutral.  As BillOhio said, don't remove the distributor unless the vacuum advance mechanism is hitting something when you adjust the distributor where you want it.

Mike.

[mikefam]

Timing specs are usually stated at a specific rpm. It is normal to adjust idle when adjusting timing.

Mike.

[mikefam]

I just noticed that you also adjusted the points. That did affect the timing. Setting ppoints at  .030 is OK to start but you should get a dwell meter and adjust them to specs. I think that about 30 degrees is correct but look it up.

As I said, adjusting points will change timing so adjust timing after adjusting points every time.

Mike.

Correction - the point gap should be about .016". which should set the dwell approx. 30deg.

[mikefam]

Unless you are into complete correctness I would install a Pertronix electronic pickup to replace trhe points, set the timing once and forget about it. That's what I did .

Mike.

[bobs69z]

Mike are you talking about timing tab when you state timing tape on dampner? Or do I need something else to set timing?  Ive been thinking of replacing points.  But want to keep original look.  Engine runs fine except when I try to restart after its been running.  It really lugs engine when I restart. When I try to retard timing it kills engine.

[bobs69z]

Someone suggested I read timing and vacuum advance by John Z.  I did a search but nothing popped up.

[mikefam]

Mike are you talking about timing tab when you state timing tape on dampner? Or do I need something else to set timing?  Ive been thinking of replacing points.  But want to keep original look.  Engine runs fine except when I try to restart after its been running.  It really lugs engine when I restart. When I try to retard timing it kills engine.

It wasn't me that mentioned timing tape but the dampner is the wheel that spins on the crankshaft. It has a timing mark that is a slot cut into the circumference of the wheel. Has that been altered in any way or covered with new markings of any sort? Calibrated/degreed tape maybe?

You can install the Pertronix pickup inside the stock distributor and no one will know but there is no reason that your points can't be adjusted properly. The beauty of the electronic pickup is it's consistency. Your points depend on the distributor bearing being tight and the point cam being good and then they wear quickly. I have no allegiance to Pertronix, any electronic pickup beats points.

Mike.

Mike.

[Tinkerr]

When you say retarding the timing it kills the engine. Are you retarding it significantly or just a couple degrees. You need to retard it in small increments and you may need to raise the idle after retarding it. I'd go in 2 degree increments, taking it for a ride after each adjustment.

[KurtS]

Points are a simple system and do work.

http://www.camaros.org/articles.shtml

[mikefam]

Points are a simple system and do work.

http://www.camaros.org/articles.shtml

Yes but I can say the same for the electronic pickup once it's installed properly. If you look at the primary and secondary spark on an electronic scope you will see just how good your distributor and points and condensor are. It will show you the spark bouncing if the distributor bearings are worn and it will show you distortions if the points are worn and/or dirty. The electronic sensor is less affected by worn bearings and there are no parts that wear and need to be replaced regularly.

Mike.

EDIT - The electronic magnetic pickup also is not affected by a worn point cam.

[olddragracer]

Something else to check. Chev harmonic balancer outer rings have a habit of slipping making the timing mark position incorrect.  The line on the balancer can be checked for correct position several ways. Bring #1 cylinder piston to top dead center, balancer line should be at 0 on the timing tab. My preferred method is to remove the valve cover on #1 cylinder and rotate the engine watching the rocker arms on #1, when exhaust valve is closing and intake valve is starting to open timing line on balancer should be at 0 on the timing tab.

[olddragracer]

The method I am describing is a quick method to check timing mark. It is not used as an exact check. Point gap is .019" with new points and is .016" when rubbing block on the points is worn in. Dwell is the number of degrees the points are closed before spark occurs for each cylinder. Dwell is checked with a Dwell Angle Meter and dwell should be 30 degrees.

[Kelley W King]

You could back off the timing a little and see how it runs for now. I think your balancer has spun or the tab is messed up. When we did not have a light handy we used to time the engine until the started dragged and back off a little and go. Not the correct way to do it but at the time a light was something you borrowed.

[bobs69z]

I haven't checked timing mark yet.  But the results....I borrowed a timing light with a timing advance dial.  Timing was at 58 deg.with vacuum plugged. Hence the hard starting when engine was hot. I cant believe engine ran as good as it did.  I adjusted points to 30.   I backed the timing down to 18 deg.,  about 30 deg with vacuum plugged in.  I couldn't lower timimg anymore because vacuum can is hitting motor bracket. May have to remove bracket or lift dist.  Havent taken a test drive yet because of weather, but car starts much easier when hot now.  I cant get car to idle below 1100/1200 rpms.  At 1000 the car slowly dies. I messed with idle mixture screws and idle screw.  Any ideas?  Thanks for everyones help.  Bob

[Stingr69]

I would used the dial back timing light to set the maximum ignition advance to 52 degrees at full advance (high RPM) with the vacuum advance disconnected and plugged.  At that point, you can look to the other concerns such as carb settings and overheating etc.  The distributor needs to be re-clocked a bit OR you can just move all the ignition wires by one terminal to give you more room to adjust the timing. If the vacuum advance can is roughly pointing at the passenger front tire you are probably in the zone. 

The ignition timing was set that way at the factory when the car was new.  Newer aftermarket kidney bean shaped cylinder heads can run a little bit less timing but original type engines with factory heads will all work set this way.

[jvb6648]

Points at .019, dwell at 30 degrees.

[red69]

I'm a little confused with the 52 degrees total advance (vacuum plugged) referred to in one of the earlier posts. For distributer part #1111480 69 manual calls for 32 degrees total centrifugal@ 4400 RPM. Add 4 degrees initial total would be 36 degrees total with no vacuum. Am I missing something?

[Stingr69]

I'm a little confused with the 52 degrees total advance (vacuum plugged) referred to in one of the earlier posts. For distributer part #1111480 69 manual calls for 32 degrees total centrifugal@ 4400 RPM. Add 4 degrees initial total would be 36 degrees total with no vacuum. Am I missing something?

Nope, you are not crazy.  I meant to type 36.  Must be getting old here.