318-3 Ignition Timing way off after replacing Distributor

[James E Vining]

SO I have another Issue, just checked the timing on my 1971 318-3 after replacing the points dist with an electronic one.
I have been running it for a few days now maybe a week or more and what seemed to be the best setting to me (adjusting it by ear and testing not to advanced by starting it hot) I had thought I was pretty close to being perfect maybe a little bit advanced, But when I connected the timing light I could hardly find the Timing mark on harmonic balancer, it appears to be about 30 Degrees advanced (Vacuum line disconnected) when I changed timing to 5 degrees advanced the engine was idling real slow so I adjusted idle screw a little but it backfires and just runs like crud.
If I set it back to about 30 degrees advanced it starts fine (Doesn't do the Typical to far advanced Stall when hot starting) seems to idle great, runs great at 2K, 3K, 4K RPM range.

SO what the heck could be up? Is there a different timing mark I am looking for on harmonic balancer other then the line all the way across the balancer??

I did run the RPM up a bit to see if centrifugal advanced worked and it appeared like it advanced properly so I do not believe the centrifugal advance to be an issue plus i double checked when I shut it off and it was moving properly and set back to no advanced when engine off.
I can not see how it could be so far  advanced and run properly nor how it could of gotten that way.
I removed the heads, intake, Dist but did not mess with the CAM, Timing Chain, or anything else, it almost seems impossible to be so far advanced and run so well yet run so bad at proper timing.
I am at a loss at what it could be, Maybe the timing light is messed up?? never used it before.
It is a Sunpro Inductive Timing Light Model # CP7515 The Type with the + and - Battery Terminals and the Spark plug wire pickup.
I got it back in like 2003 or so I do not  think I have used it, at least not since 2005.

[legomybago]

If it runs good.....great....then your in time. Maybe be sure your on #1 cylinder with timing light? Or find top dead center on #1 and see where you line up... I've had the same issue before.... I was still learning how to tune an engine and it through me for an absolute loop!! I did every kind of top dead center trick there is.....found out I had a differant balancer!! Lesson was learned D:oH!

[James E Vining]

Could be the case, I looked an when I have The rotor pointing at #1 Plug the line is at about 20 degree advanced but that makes no sense since the Reluctor and PU are lined up perfectly and the Rotor lines up with the cap and all runs great.
I found a # on the Harmonic balancer so I will write  it down and see if that will shed any light on the issue.
Heck for all I know the Timing Marks themselves could be Bent or not in correct location, Especially with all the other Screwy things I have found since I started working on the MH, AT least it was Free so I can't complain to much.

[legomybago]

From reading up on this site...some people have oddball/different year timing covers on there dodge engines too...with different timing pointers Hm? You never no? Until you do what you are doing and figuring it out!!

I like free. Thats a good start for a MH project. I paid 500 for mine, but it will be alot more dough before she sees any travel time W%

[James E Vining]

I,m Pretty Lucky, I have come to believe by the way the engine acts and looked when I had the heads off that it must have 32,000 Miles and not 132,000 as I have seen engines with 100,000+ and they normally have substantial Ring ridges where this one has none.
Plus it is pretty much drive able now after replacing carb, intake and Dist.
The Issue it has was someone Pulled the Cabinets, closets and painted the entire interior white.
SO I need to replace/rebuild the cabinets and replace the wood paneling to get it back to original.
I have some wiring issues as far as the 120V and 12V Interior Goes but the chassis and the chassis electrical has all been fixed now with pretty minor work at least to me it was minor to others it may have been a major Issue and when I was looking at the wiring under the dash at first I thought it was next to impossible but now I'm finished it wasn't so bad.
I still have to find a Water Heater ( as it was Removed for some reason) and figure out the short in the 12V side of the Forced air heater and Either fix or replace the Fridge but as it is now I can at least use it to camp and so on.

[Oz]

Do I have this right... you did figure out the problem?

[James E Vining]

Oh man did I ever, I started a Post under appliances to cover my Forced air Issues.
As far as my Ignition I think the article about Manifold Vacuum VS Ported Spark vacuum totally solved my issues.
I always wondered why they say remove the Vacuum from Dist. when at Idle with the ported Vacuum advance you have no advance or vacuum now I remember why because it is Backwards from what it should be in reality. leave it to Government to cause issues to a good thing by making manufacturers change things.
I am going to redo the vacuum advance to manifold vacuum and reset everything according to the specs and see if that fixes it I bet it does.
as I figure with Vacuum advance full I get about 20 Degrees (just guestimating) have not gotten my Mr. Gasket  Harmonic balancer Timing tape yet.
So if without any Vacuum advance at Idle I have to set it at about 25 advanced then with vacuum at full (idle I get 22 in/hg Vacuum) and using 5 BTDC I will be dead on.
I bet this thing would of Pinged and panged and beat itself to death if I left it the way it was a drove it under load OMG its crazy.

Yes I used a Vacuum Pump I bought to bleed brakes etc. to check the advance of the Dist Vacuum at idle and by judging amount the Mark advanced around the harmonic balancer way off of timing marks I think it was about 20 anyway.
I will keep ya posted I am pretty excited about this and it reminds me of my old 383 I had in a 70 duster back in early mid 80's how it was plumbed and things worked.
69 383 was  Government was lucky I even had a PCV system let alone all the other bunk stuff they added later on LOL.

[legomybago]

(ported vac to dist.) You will never have accurate timing with straight manifold vac. i.e. pressing on your vacuum operated brakes at an idle....your timing will change...so will your idle.

[DaveVA78Chieftain]

Hope you understood the Vacuum advance description properly.
For 1973 318-3 electronic ignition MH distributor:
At wide open throttle, there is minimum vacuum.  In that situation, the total advance only reflects the mechanical advance (approx 15 deg max) plus initial setting (2.5)
Max advance is when the engine is at cruise with minimum load (flat surface, no headwind) which results in a high vacuum.  So, 15 mechanical + 2.5 initial + 15 vacuum = 32.5 total.

Ported vacuum port - At idle there is no vacuum.  When you depress the accelerator the port starts to see manifold vacuum.  At idle, timing mark is basically at initial setting

Manifold port - The distributor will see max vacuum therefore maximum advance.  As you open the throttle vacuum deceases retarding advance.

Vacuum is used to detect engine load.  As engine load increases (acceleration) vacuum drops.  As engine load decreases (least amount of pedal to maintain speed), vacuum increases thereby increasing advance.




Dave

[Oz]

Oh man... now Dave is blowing my mind with charts and graphs about vaccuum!  How does that brain fit in his head....

[James E Vining]

Great Graphs, Thanks, Ya I totally understood the Vacuum advance info, it just makes perfect sense to me, Plus I have dealt with mostly pre-75 MOPAR Vehicles and Engines and I know for a fact the 69 383 I had  in a 70 Duster used Manifold Vacuum to Dist as I remember I had to plug the Line at idle when adjusting timing and when connected it was advanced.
I have to re read the article again as I thought I remember them talking about a Advance of 50 Degrees max on Pump gas and so on.
That is at cruising speed and max Manifold Vacuum.
Plus I usually always read articles 2-3 times just to make sure I didn't miss anything plus It helps me process all the info and memorize it better,
I can't wait to get the Old Motor Manuals my dad has had since Before I was born they have such awesome info in there, that was how I learned to rebuild my alternators, Starters and so on long before the Idea of just buying a new one and replacing it like they do now.
If I remember correctly he has 2 or 3 of them Large say 500 Pages covering everything from Engine rebuilding to tranny rebuilding and so on.
Heck you go to a Large Chain Parts store now and ask for say Alternator Brushes or bearings and they think you are a Nut Case.