Author Topic: Timing issue?  (Read 7735 times)

bobs69z

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Timing issue?
« on: May 10, 2019, 05:30:12 PM »
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
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jdv69z

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Re: Timing issue?
« Reply #1 on: May 10, 2019, 07:02:34 PM »
Maybe too far advanced? Mine is set at about 12 degrees BTDC. That's static only. Not vacuum or centrifugal.
Jimmy V.

mikefam

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Re: Timing issue?
« Reply #2 on: May 10, 2019, 11:15:04 PM »
Are you disabling the vacuum advance by removing the vacuum hose from the distributor and plugging it up?
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Timing issue?
« Reply #3 on: May 10, 2019, 11:17:46 PM »
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.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

bobs69z

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Re: Timing issue?
« Reply #4 on: May 11, 2019, 02:40:53 AM »
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.
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BillOhio

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Re: Timing issue?
« Reply #5 on: May 11, 2019, 02:11:15 PM »
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?? 
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mikefam

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Re: Timing issue?
« Reply #6 on: May 12, 2019, 03:19:30 PM »
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.
« Last Edit: May 12, 2019, 03:40:01 PM by mikefam »
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Timing issue?
« Reply #7 on: May 12, 2019, 03:22:18 PM »
Timing specs are usually stated at a specific rpm. It is normal to adjust idle when adjusting timing.

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Timing issue?
« Reply #8 on: May 12, 2019, 03:51:29 PM »
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.
« Last Edit: May 12, 2019, 04:50:09 PM by mikefam »
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Timing issue?
« Reply #9 on: May 12, 2019, 04:53:04 PM »
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.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

bobs69z

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Re: Timing issue?
« Reply #10 on: May 12, 2019, 07:22:48 PM »
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.
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bobs69z

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Re: Timing issue?
« Reply #11 on: May 12, 2019, 07:26:09 PM »
Someone suggested I read timing and vacuum advance by John Z.  I did a search but nothing popped up.
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mikefam

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Re: Timing issue?
« Reply #12 on: May 12, 2019, 07:36:54 PM »
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.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

Tinkerr

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Re: Timing issue?
« Reply #13 on: May 12, 2019, 08:29:13 PM »
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

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Re: Timing issue?
« Reply #14 on: May 13, 2019, 04:59:43 PM »
Points are a simple system and do work.

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