1991 OMC 5.0 Sweet 16 Coil Problem? No Spark

[BOSTONCAMARO]

Ok so we have a 1991 OMC Cobra outdrive 5 liter Ford. The main circuit breaker went, so we lost all power, the boat had seen salt water use so perhas this is the issue, it is 20 plus yeas old. So while my dad was trouble shooting this, he jumped some wires and noticed the coil had gotten real hot. So a week later, back in Maine, install new circuit breaker, we have all electric power back, bilge, lgiths, turns over etc but no spark. The boat has real good juice going into the coil, we have NO spark at all and when cranking the key the negative side of the coil only VERY dimly lights a test light. The positive side of coil, wire going to it has real strong juice.

I am thinking it is the coil? or, should this boat have points ignition? we didnt pull the cap yet.

I appreciate all input, thanks, Tim

[Conquistador_del_mar]

Tim,
Last month, I bought a 1989 Four Winns Horizon 200 with a 4.3 OMC Cobra for my step daughter and had all the maintenance done. It is a points type distributor so yours being 2 years newer is likely points type also. Bill

[mattyboy]

John C just went thru this on his ford search for that thread it has some troubleshooting and what was the solution

[BOSTONCAMARO]

my dad called, he swapped coil and still didnt work, he swapped in coil that I know is good

he also pulled cap and it is an electronic ignition

the coil that was in the boat, was original to the boat and had a lable on it stating there is a resistor

anyone know where a balasrt resistor on this boat would be, is there one that is used when the boat has electronic igintion....maybe it is the module itself in distributor that failed?

thanks!

[MOP]

First guess would be the ignition pack mounted on the starboard manifold, no points just a trigger in the distributor. Do you know what blew the 50AMP fuse? May have caused that and possibly other issues.

Phil

[BOSTONCAMARO]

we do not know what blew the 50 amp fuse, the boat was used in salt and is a 1991, so does have some age, we also did find that when working on it, basically the terminal stud pulled right out of it, basically the unit itself was crumbling, so perhaps failed after years of corrosion? after fuse blew we towed back to our dock, my dad had jumped some wires, finally got power so that the boat would turn over, had all electric, but we are thinking by doing that, we may have caused another issue, at this time the coil was super hot, my dad had rested his arm on it (this was about an hour or two after fuse blew, not right after and the coil was not hot before he started jumping wires) so maybe it is the ignition pack rather than the distributor.

Anyone have part numbers, pictures of this ignition pack, I am in the Boston area now and my dad is in Maine, so want to do some legwork on finding parts to bring up next weekend.

All other wires, battery cables etc are in good shape, nothing seems to be arcing out, my dad has been checking conductivity on everything, checked the coil and spare coil we brought up...it is definitely getting power to distributor, good power into coil but no spark and weak juice on test light on negative side of coil when turning over. I appreciate everyone's input

[mattyboy]

my thoughts would be, by jumping wires you bypassed the resistor or resistor wire sending 12 volts to the coil instead of 9 volts causing it to heat up and fry. not sure why the main breaker went

[BOSTONCAMARO]

my thoughts would be, by jumping wires you bypassed the resistor or resistor wire sending 12 volts to the coil instead of 9 volts causing it to heat up and fry. not sure why the main breaker went

so possibly, the ignition pack is fried....because of the jumping that took place i.e. 12 instead of 9 volts

so this boat should have a resistor? where would it be located most likely

thanks again!

[dsparis]

isn't 12v sent to the coil while cranking to assist cold starts ?

[MOP]

I think the stock OMC packs are NLA! Sierra may be making them now, there are numbers stamped on the pack. Try a Google search that may dig one up.

Phil

[mattyboy]

dsparis,
yes then when the key is released from the start posistion the coil get 9 volts thru the ballast resistor or the resistor wire
if it is not a coil that has an internal resistor and 12 volts is present all the time while in the on position it will heat up and most likely fail plus it is sending more juice down stream which can cause other issues.

Boston check this thread it has some info in it

http://www.donzi.net/forums/showthread.php?68709-First-splash-13-good-news-bad-news&highlight=

[BOSTONCAMARO]

I read that thread, seems similar to my problem....so he is talking about his module, is he talking about the trigger in the distributor or the ignition pack?

If in the distributor, be great to just swap in a new reman'd one

[MOP]

Module/Pack the trigger usually does not take the hit, it only sends a signal to the pack to fire.

[BOSTONCAMARO]

MOP so what are you thinking it may be?

My dad emailed me, he said the only thing on the ex manifold is the ESA, is that what we are calling the ignition pack? just want to get the terminology correct, I thought the ESA controlled shifting interrupt only? is it also the ignition pack?

That is part number 987564

The boat distributor number is 0986969 which updates to 3854040 module inside distributor is 3854077

[BOSTONCAMARO]

can someone help me clarify what I posted in my last response, just want to get parts on order as I am heading to Maine Friday and maybe I can second day air some parts so I have them,

Can I swap in a ready to run MSD distributor?

thanks, Tim

[mattyboy]

Tim,

I am not sure on the OMC 5.0 with the esa and shift interupt. I have an '87 5.0 ho on an old volvo with no shift interupt or esa it runs a coil with an internal resistor and a Mallory marine distributor that is electronic( no points).

[MOP]

MOP so what are you thinking it may be?

My dad emailed me, he said the only thing on the ex manifold is the ESA, is that what we are calling the ignition pack? just want to get the terminology correct, I thought the ESA controlled shifting interrupt only? is it also the ignition pack?

That is part number 987564

The boat distributor number is 0986969 which updates to 3854040 module inside distributor is 3854077

My 16 was a 5.0 it had the pack/ESA on the Stb. manifold, yes the pack makes the engine studder momentarily when shifting so the lower gears fully engage. It also fires the coil when the triggered by the coils sensor. Though not likely have you checked the shift interrupt switch on the port manifold? There is a two pin connector, unplug it to see if it gets spark. Possibly while trouble shooting it got knocked out of wack by leaning on the shift cable, years back it had me going for awhile.

To swap distributors you may need an interrupt kit not sure on that one.

Phil

[BOSTONCAMARO]

My 16 was a 5.0 it had the pack/ESA on the Stb. manifold, yes the pack makes the engine studder momentarily when shifting so the lower gears fully engage. It also fires the coil when the triggered by the coils sensor. Though not likely have you checked the shift interrupt switch on the port manifold? There is a two pin connector, unplug it to see if it gets spark. Possibly while trouble shooting it got knocked out of wack by leaning on the shift cable, years back it had me going for awhile.

To swap distributors you may need an interrupt kit not sure on that one.

Phil



Also, so the ESA not only works to interrupt, it is also what we are calling 'ignition pack' so perhaps that has failed..

I may plan on doing distributor and ESA, will check for spark though on the interrupt switch on port manifold

Ok a couple more questions

1. So should I use a test light to see if spark is coming from that two pin connector when engine is being cranked?

2. Any way to check distributor, see if power is there?

thanks!

[MOP]

It just a switch that signals the pack to studder, it senses the amount of pull tension on the cable as you shift. Just unplug it to see if it "might" be an issue, like I said it is only a shot but worth trying!

[BOSTONCAMARO]

ok so the part on the port manifold, the switch......so what will unplugging it do? if everything was indeed working in the boat, would leaving this unplugged make it so the boat doesn't start?





ok, will do and on the starboard manifold the esa is what is also called the ignition pack?

my dad picked up a new resistor wire and is going to check continuity on the one in the boat now (for the coil)

then likely plan on the esa and distributor....could be module in distributor but it does have corrosion from salt so may just swap in new unit

thanks, tim

[BOSTONCAMARO]

my dad had bumped into light switch, lights were left on and battery was now dead so couldnt do any testing this weekend, so want to get some parts to bring up before next time up there....

what do you guys recommend for a distributor to replace the prestolite? the prestolite is a 2 wire, negative and positive leads only and does not have vacuum advance, I found this online and seems to be the same design.

I likely will replace distributor and esa....starting with distributor, I did not confirm yet if module/trigger in distributor is bad but it is pretty heavily corroded from years of neglect and salt water...,I did not take a look yet, but my dad checked it out, said it is heavy with white crust etc all around module etc

http://www.ebay.com/itm/Plug-N-Play-Ignitor-II-Billet-Distributor-Ford-289-302-Pertronix-Socket-Cap-SBF/390352457511?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%2 6asc%3D11%26meid%3D355715651122533557%26pid%3D1000 11%26prg%3D1005%26rk%3D5%26rkt%3D5%26sd%3D30094037 6119%26

[mattyboy]

make sure the distributor is marine rated

i used a mallory like this one

http://www.ebay.com/itm/Mallory-Distributor-Marine-Magnetic-Pickup-Mechanical-Advance-Ford-221-302-Each-/111114397172?pt=Motors_Car_Truck_Parts_Accessories&hash=item19deef25f4&vxp=mtr

[BOSTONCAMARO]

yeah my dad will check with Petronix....is that Mallory a two lead, ready to run? just a black and red lead coming from it that I can drop in and wire up

I have used Mallory stuff in our cars, but mostly run MSD

I just want something close to stock, regardless of my spark issue, the distributor should be replaced due to corrosion.I want something that I can drop in, eliminate the dist as an issue, then replace other stuff as needed

thanks, Tim

[mattyboy]

the mallory has a 3 wire harness

+ of the coil RED

- of the coil GREEN

ground BROWN

out of the box, dropped it in, wired it up, timed it, done.

[SanDogDewey]

+1 on the Mallory unit.

[BOSTONCAMARO]

ok, thanks, we may go this route...however as we had some shifting issues as well (even though have new cable)

perhaps it is the ESA, we are going to drop it off at Dick Weavers this weekend have him assess it, fix it, we just have so many other projects going..69 Corvette, 460 inch 13 to 1 compression Big Block 68 Gasser style Camaro and others...

We will get an estimate from Dick and likely just have him fix it, summer is too short around here!

[joseph m. hahnl]

Does it have a lanyard? :propeller:

[MOP]

Remember it is very important to have the shift interrupt, even though OMC cut the dog ramps to 5 degrees to help with engagement you lose the lower in short order without it.

P.S. if you do change out the distributor make sure it has the interrupt and it works correctly, me I would fix the problem not just throw more money at it.

[BOSTONCAMARO]

there is a mercruiser conversion we will likely do, keeps the interrupt but uses mercruiser parts

yes has lanyard, we also were thinking may be that...we dropped it off at marina, it is someone who is well known in the donzi world but don't want to mention it here, but he will get it fixed, we have just been so busy with other projects, 68 Camaro Gasser, 69 Corvette etc that simple will be worth having someone fix it...

[BOSTONCAMARO]

It was the election electronic shift assist...running now but cable needs adjust'm ent, doing mercury shift assist conversion ....also shifter as can shift without pressing extent button