MerCruiser 3.0L 140 Electronic Ignition Grounding Question

[Jacalore]

This (1985) engine stalls when pushed over 1500 rpm. Timing was off, adjusted to 6? BTDC at idle (700 rpm). Mix adj has little affect, idles a bit rough. Talking to PO, he installed a PerTronix Igniter electronic ignition system. Afterwards stalling problem began. He thought it was the carb, but I've swapped carbs with same symptom. So I'm focusing on the elec Ig system. When I measure across the coil it reads 3.3 ohms, which is correct, I believe. When I measure the black wire from Igniter (to neg side of coil) to ground it measures 42 ohms. I was looking for a reading closer to a couple ohms. Is there supposed to be some sort of resistance between distributor ground and battery ground?
Thanks.

 

[alldodge]

Re: MerCruiser 3.0L 140 Electronic Ignition Grounding Question

This (1985) engine stalls when pushed over 1500 rpm. Timing was off, adjusted to 6? BTDC at idle (700 rpm). Mix adj has little affect, idles a bit rough. Talking to PO, he installed a PerTronix Igniter electronic ignition system. Afterwards stalling problem began. He thought it was the carb, but I've swapped carbs with same symptom. So I'm focusing on the elec Ig system. When I measure across the coil it reads 3.3 ohms, which is correct, I believe. When I measure the black wire from Igniter (to neg side of coil) to ground it measures 42 ohms. I was looking for a reading closer to a couple ohms. Is there supposed to be some sort of resistance between distributor ground and battery ground?
Thanks.

Have you made sure your air gap between the magnetic pickup and top ring set correctly?
www.boatfix.com/merc/Servmanl/16/16F4R2.PDF‎

 

[Don S]

Re: MerCruiser 3.0L 140 Electronic Ignition Grounding Question

The - terminal of the coil is NOT a ground. The module inside the distributor is the actual ground. Not sure how, what or where you are measuring to get the reading you are, or if the measurements you are taking means anything.

 

[Jacalore]

Re: MerCruiser 3.0L 140 Electronic Ignition Grounding Question

I'm measuring from coil neg to ground. PerTronix warns against bad grounds and low supply voltage. But when i asked about this condition, tjey said, "You may read resistance because the Ignitor sends a control signal thru the ground wire." Which, to me, makes no sense.

 

[Don S]

Re: MerCruiser 3.0L 140 Electronic Ignition Grounding Question

Got me, I would rather go back to points than Pertronix. At least there is information available to troubleshoot.

If you want to go electronic ignition, get something that works and there is plenty of info on. An EST like this 3.0L Delco Voyager EST Marine Electronic Distributor Kit
Mercruiser, Volvo and every other manufacturer using the 3.0L uses it.

 

[Jacalore]

Re: MerCruiser 3.0L 140 Electronic Ignition Grounding Question

I am leaning your way, Don. Back to basics just might be the answer.