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Electronic advance

My mechanic has told me that my ignition module is bad and that’s why it won’t advance. I replaced it with the lx340 module (automotive I believe) and it’s still not advancing. He said I probably got a bad ignition module and to buy another one. I did and same thing, won’t advance. Is there a difference between automotive and marine ignition modules? This is on a 1990 270 crusader.
 
I replaced my old 1977 Crusader 270 distributors with the Delco EST type. I'm assuming you have the OEM version of this. I went through the distributor not advancing with a couple aftermarket modules. In addition to not advancing, the aftermarket modules didn't react to 12v being applied during the base timing adjustment. Since then I've found that the genuine AC Delco module will provide advance and the base timing can be set properly. The AC Delco part number for the module is D1965A.
Delco Voyager module D1965A.jpg
 
Against regs and plain old safety to use an automotive distributor in a boat.... in addition to the fact that the advance curves and sometimes the whole advance mechanism is different.
 
I'd say its more of a by-product of aftermarket vs OEM....with the exception of the marine use, the other applications using that distributor use an ECM-controlled timing scheme. I'd bet many aftermarket types don't even attempt to add an internal timing function to their modules as they never get used. The DELCO parts have very few complaints...
 
All seems to be fixed now. My initial symptoms were after running hard for about 30 minutes the engine would drop RPM's from 3200 down to 27-2800. Once it started it would progressively get worse but I would run at lower RPM, say 2000, without any issues. It stalled out on me on one occasion but fired right back up. I also noticed that my throttles were no longer even and I had to keep advancing one further and further. Eventually it came to the point where my port engine would max out at 3200 rpm even though the throttle was fully forward. Backing it down it had quite a bit of play until the RPM's actually dropped. On the hole shot both throttles were even until around 2200 rpm. That's about where I had to start advancing the port throttle more and more to keep the RPM's equal. Got that ignition module changed out with the correct one and the boat is running great now.
 
Against regs and plain old safety to use an automotive distributor in a boat.... in addition to the fact that the advance curves and sometimes the whole advance mechanism is different.

The newer electronic auto distributors are the exact same distributor as the marine version. There is no difference, and it is not against any “regs” to use the newer, electronic ignition distributor on a vessel, as they comply with marine specs.
 
The newer electronic auto distributors are the exact same distributor as the marine version. There is no difference, and it is not against any “regs” to use the newer, electronic ignition distributor on a vessel, as they comply with marine specs.



If you are including the mechanically advancing electronic ignition distributors in with that statement, that is incorrect!
The advance curve alone will be incorrect for the Marine Engine.


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If you are including the mechanically advancing electronic ignition distributors in with that statement, that is incorrect!
The advance curve alone will be incorrect for the Marine Engine.

Nope, only referring to the AC Delco electronic Distributor being discussed here, which is the exact same part number, auto or marine. Mercruiser simply doubles the price on the "marine version."
 
Just finished an episode with my 1992 Crusader 350ci's, where one engine periodically wouldn't rev as high as the other and needed more throttale. Turned out the reluctor had loosed from the distributor shaft, and could rotate slightly, changing the timing. The replacement distributor came with a defective module, which would cut ignition when throttle given a short burst & then closed.
 
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Just finished an episode with my 1992 Crusader 350ci's, where one engine periodically wouldn't rev as high as the other and needed more throttale. Turned out the reluctor had loosed from the distributor shaft, and could rotate slightly, changing the timing.

A VR (variable reluctor) ignition system's all steel reluctor is typically press fitted onto the shaft.
It's highly unlikely that a reluctor would come loose.


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By chance are you referring to a Hall Effect magnetic triggering wheel, such as with Pertronix, or perhaps several other brands that use Hall Effect?
These can come loose.

44715483_L_94dfe421-f6aa-411f-bd33-be36703944d7.jpg
 
In the attached photo from the topr of the Delco distributor, note the badly rusted 8-point star. That is what was loose on the shaft. The missing point broke off when touched.
 
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In the attached photo from the topr of the Delco distributor, note the badly rusted 8-point star.
The eight point star would be the reluctor wheel.
I'm not seeing a badly rusted Delco system reluctor wheel in any of the photos in this thread.



That is what was loose on the shaft. The missing point broke off when touched.
Do you have pictures of this that you would be willing to share with us?
 
I tried attaching a picture, but apparently the effort failed. Any tips on how to add a picture?

It was definitely loose on the shaft--could be rotated slightly. The tech says he's seen it once before.

Actually, this did not end the saga. Two new distributors were installed. Both had problems. On one, if you give a short burst of throttle and then pull to idle, the engine would die. With a timing light on the engine, te light would go black for a bit, indicating engine cut off. Replaced the ignition module, and no further problem. On the other engine, idle speed would vary by as much as 200 rpm, and digital tach was ranging up and down at slow RPMs. Replaced module, and that went away.
 
As I said, I have been unable to figure out how to post a picture. Clicking on the icon and following it does nothing. The distributor with the loose reluctor wheel was the original Delco EST that came on the engine.
 
I believe that the modern day Delco EST system will be using photo-eye triggering..... not VR.


As for posting images, place your curser where you want the image to appear.

Then click on the "insert image" icon above. That icon will only be visible when posting.

Then look at the tabs, and click on the "from computer" tab.

Then click on "chose file".

That will open up your stash of images.

Scroll though your images until you locate the one that you want to post.

Once you select the image, you will be directed to "upload file(s)".

Click on "upload file(s)".

That should place your image in with your text.

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You can also add web hosted images by copying an image to your clip board by using "Ctrl + C".
Then select where you want the image to appear, and place your curser there.
Then hit "Ctrl + V".


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what would be the basis for that assumption???
rjrva said in post #12: "Turned out the reluctor had loosen from the distributor shaft, and could rotate slightly, changing the timing."In post #14 he said it was a Delco and that the reluctor was badly rusted...... and in post #16 he said it was a new system.
In post #17 I asked if he could post an image of the distributor and the reluctor.

Pickup coils and reluctors have been operating off magnetic principles for well over a century....
Understood.
Mallory and Chrysler have used VR triggering for years.
Merc's EST and I believe the Delco's EST use photo-eye triggering..... yes/no?
Pertronix and I believe today's Prestolite use Hall Effect triggering.

Mark, when rjrva mentioned that the "reluctor" loosened up, I was surprised to hear that the Delco used VR triggering.
And if Delco does, I would be even more surprised to learn that their reluctor could loosen up from the shaft.


Hopefully rjrva will figure out how to post images.


Meanwhile, it looks like Hypocolemicshock (the OP here) got his questions answered and is up and running again.

I hope that he didn't mind the Hy-Jacking of his thread.


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