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timing a new delco voyager est distributor question

Thanks. I have a log book that says the previous owner had these distributors installed in 2005. I have had this boat for 5 years and it seems to run fine. I have put 350 hours on it since I got it. I changed plugs, cap and rotor when I first got it and again this Spring and added new wires.
Would the boat run normally with that shunt plugged in all the time? My understanding is that the advance wouldn't work with it plugged in or do I have that wrong?
 
that's a good question....I suspect you have no ECU so the distributor works in standalone mode.

with the shunt plugged in, how the module behaves is driven by what goes on with the brown wire in the connector...the pic doesn't show the other end. I would suggest you can measure the timing to see if it advances (with RPM) as it is connected. All of the data I have indicates the shunt should NOT be in for autonomous operation.
 
Realcaptron,

abive you mention different fuel fuel consumption and fuel coming out of primaries at idle on the higher consumption engine. To me this looks like the fuel level in the bowl is too high from either too high fuel pressure or needle and seat in carb is dirty or defective. Would verify fuel pressure is 5-6 psi max and then think about cleaning and rebuilding the carb.
 
guys, I'm the op and its been a while since I checked in. Here is an update. I contacted to company that sold me the new Delco distributors and they seemed convinced I had 2 new distributors, each with bad ignition modules. Without any hassle at all, they immediately shipped me 2 new modules. I installed them and voila...both distributors advancing great. After some tickling with idle mixture, optimizing vacuum, idle speed setting and the timing, I achieved roughly 8* advanced at idle with the shunt, and 28* with shunt out and 2500 rpms on starboard. The port side also at 8 * with shunt but that one advanced to 32* at 2500 rpms. After discussing with tech rep at the merchant, I just retarded the distributor enough to get the advance at 2500 rpm below 30*. I went for 28* to match the other side.
I explained to the tech rep that I have a heavy 32' old school sportfisherman and that I do not intend to race this boat around. Most of my time on the water will be going from point a to point b at 1500 rpms or so netting about 9 knts. I want to conserve fuel.
HOWEVER....I still notice a strange cloudy emission in the starboard exhaust that clears up as it warms and smells gassy. When shutting it down and pulling off the arrestor, I can see that the secondary plates on my Holley 0915-1 carb are wet, in fact pooling a little fuel. I know that should not be, so I am going to pull the carb and have a local carb shop rebuild it for me. I hope that the rebuilt carb will clear up the overly rich exhaust. I am open to your thoughts. Thanks for continued help.
 
good deal on the modules....but 2500 seems a little early to get to the top of the advance curve - is there any more 'advance' above 2500?

on the carb, have you verified the choke adjustment? same for the float levels?
 
makomark said:
good deal on the modules....but 2500 seems a little early to get to the top of the advance curve - is there any more 'advance' above 2500?

on the carb, have you verified the choke adjustment? same for the float levels?
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Mark, I have only revved them in slip to 2500 simply because I find it a little scary to crawl down between them at hi rpms. Thinking I rarely will run this boat at a true cruise plane speed, so far I just opted to stop it at 2500. I believe the distributors will advance further.
On carb, it is electric choke and I am able to see it is fully opening as it should. Question...these chokes are energized anytime the ignition is on and they feel warm, almost hot to touch. Is that to be expected?
On float level, I have not checked. Is that an easy process? The idle mixture screws on the rich engine do not stall out the engine when turned all the way in as I think they should. Currently they are only backed out 1/2 turn and that seems to yield optimum vacuum pressure and smooth idle. Can I just replace the idle mixture needles and expect a different result without removing and cleaning out the carb?
Out of curiosity, have you any thoughts on what the cloudy emission from exhaust might be? Hard to describe it. It looks almost like alka seltzer in the exhaust water when cold until fully warmed. It looks like a mixture of bubbles and sediment that sort of hangs in the water and disappears, leaving a very very fine slick that is barely noticeable. It does smell gassy back there. The oil looks good on dipstick and is not lowering. Its a raw water cooled boat, so part of me wonders if it is sea water deposits clearing out of the cooling passages on start up but the port engine is not doing that at all.
 
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realcaptron said:
...................... I installed them and voila...both distributors advancing great.
Have you plotted this out in graph form?

After some tickling with idle mixture, optimizing vacuum, idle speed setting and the timing, I achieved roughly 8* advanced at idle with the shunt, and 28* with shunt out and 2500 rpm on starboard.
Look up your OEM advance curve for YOUR engine.
I'm thinking that 28* BTDC @ 2.5K rpm is far too early.

The port side also at 8 * with shunt but that one advanced to 32* at 2500 rpm.
Again, I would say that 32* is excessive and is far too early!

After discussing with tech rep at the merchant, I just retarded the distributor enough to get the advance at 2500 rpm below 30*. I went for 28* to match the other side.
I explained to the tech rep that I have a heavy 32' old school sportfisherman and that I do not intend to race this boat around.
This has ZERO to do with racing..... it has to do with preventing detonation damage!
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makomark said:
good deal on the modules.... but 2500 seems a little early to get to the top of the advance curve -

I fully agree with Mark!

Again, I would suggest that you look up the OEM ignition advance curve graph for YOUR Engine!
Click to expand...

By the way..... RPM = Revolutions Per Minute....... ("Revolutions" is already plural!) :D


.
 
RicardoMarine said:
.......................




By the way..... RPM = Revolutions Per Minute....... ("Revolutions" is already plural!) :D


.
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Hey, this isn't Rick from boc is it? I think I recognize the technical approach:). Rick, be nice to me. I've been told just to make sure it's not advancing beyond 30* , period, to prevent detonation. Others have told me that if I only want to troll around at slow speed and advance is accordingly below 30*, the engine will be safe. Your boc buddy, ron.
 
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realcaptron said:
Hey, this isn't Rick from boc is it? I think I recognize the technical approach:).
Yep..... it sure is!
RicardoMarine was my business name during the time that I was active with the AQ series Volvo Penta service work.

Rick, be nice to me. I've been told just to make sure it's not advancing beyond 30* , period, to prevent detonation.
Well, that info is incorrect! In order to be useful, an RPM must be associated with the number of degrees advance! If not...... the number is completely meaningless!
Look up your Engine's OEM ignition advance curve. You will see that the TA will be associated with an RPM.


Others have told me that if I only want to troll around at slow speed and advance is accordingly below 30*, the engine will be safe.
Again, this is misinformation and is incomplete!
Click to expand...
 
Base timing is not as important as max spark advance. Have you checked for timing chain slop? Have you checked for true TDC? Match all in spark advance for both engines and see how she performs?
 
With tongue somewhat in cheek....Neil Armstrong landed on the moon with less consternation than I am having grasping total advance from all the different explanations on multiple forums. PLEASE...is the total advance simply the timing reading at timing reading at any given rpm above idle? Other posts are implying you add base timing to higher rpm timing to net total advance, but others saying you just read the timing at higher rpms and whatever that is...is the total advance. For the love of everything holy , can someone clarify to this monkee.
 
MAX timing is what you wind up with, in the case of your electronic distributors, when the timing wont advance any further. so you get 28 deg @ 3000 RPM then you won't get any more advance Above 3000. Base timing is what you get at idle....and isn't important as long as the engine will start when hot. Much of the confusion is due to the factory data - Mercruiser in particular omits the base timing values from their timing curves....

As far a the carbs go, on the engine that keeps running with the idle mixture screws closed, that means fuel is entering the airstream thru another means. It could be the float level(s) is(are) too high....most holleys have sight plugs you can see the fuel level thru...if it is not that, then an overhaul would be wise.
 
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realcaptron said:
........ PLEASE...is the total advance simply the timing reading at any given rpm above idle?

NO

Other posts are implying you add base timing to higher rpm timing to net total advance, but others saying you just read the timing at higher rpms and whatever that is...is the total advance. For the love of everything holy , can someone clarify to this monkee.

Total Advance (aka TA) is the amount of ignition lead (ignition advance) as a result of both “BASE” and the degrees of progressive spark lead (in crankshaft degrees). The system’s advancing mechanism ( be it mechanical or EST) adds to what we have set as BASE advance.

In other words, if you were to add the BASE advance degrees to the progressive advance degrees (at the point at which it limits out), that would be your TA.

In other words #2, Total Advance is what all cylinders see at the RPM at which the ignition spark no longer advances!

TA is by far the most important aspect of ignition timing...... and the RPM at which TA occurs is critical!

Do not let anyone confuse you with a haphazard explanation that deviates from this!
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makomark said:
MAX timing is what you wind up with, in the case of your electronic distributors, when the timing wont advance any further. so you get 28 deg @ 3000 RPM then you won't get any more advance Above 3000. Base timing is what you get at idle....and isn't important as long as the engine will start when hot. Much of the confusion is due to the factory data - Mercruiser in particular omits the base timing values from their timing curves....

As far a the carbs go, on the engine that keeps running with the idle mixture screws closed, that means fuel is entering the airstream thru another means. It could be the float level(s) is(are) too high....most holleys have sight plugs you can see the fuel level thru...if it is not that, then an overhaul would be wise.
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Thanks as always Mark
I'm gonna set it to 3000 rpms and retard or advance distributor to no higher than 28* and call it a day. I will pull right plugs and see if float s are too high as well. Did you have any thought on the weird exhaust discharge?
 
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.................... Much of the confusion is due to the factory data - Mercruiser in particular omits the base timing values from their timing curves....
Most all Marine Engine ignition advance curve graphs will be minus the BASE advance value. In other words, the graph will only show what the progressive is offering.
When doing the math and/or calculating what the TA will be, BASE must always be added to that value!

However, when we strobe the timing marks dynamically, we will always see the sum of BASE and Progressive.


Also, not all ignition systems will be Full-In by 3,200 RPM. Some of the Mercruiser curve graphs will show a continued advance past 3,200 RPM.
I am not an engineer, but I believe that at/near 2,800/3,200 RPM (for V-8 engines), correct advance is most critical!
Click to expand...
 
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