OMC ESA operation...

[ryanorr280]

i have an 88 OMC Cobra drive 350 motor. having multiple shifting problems...

the one i am working on at the moment is that the ESA does not stumble the engine when engaged. i have looked in my service manual, and see where it shows the wire from the ESA going to the - side of the coil. my question is, is this supposed to send a ground, or a power to the coil? also, mine has an HEI distributor, so i don't have a - terminal. can i route the positive wire to the coil through a relay that would take the power from the coil when the ESA engages? it would cause a stall if it stays engaged to long, but would it allow it to drop into/out of gear easily? thanks in advance

also, is there supposed to be a gasket between the upper/lower units? or is it just a machined surface fit..

 

[bruceb58]

Re: OMC ESA operation...

That motor did not comne with an HEI distributor. Post a picture of what you have.

 

[ryanorr280]

Re: OMC ESA operation...

I agree, this is not the original motor, previous owner told me it was out of a 94 suburban. Will b probably Sunday before I can get pics though, just kinda wondered if killing the coil would do the same thing...

 

[T-Bone Coug]

Re: OMC ESA operation...

I hope that "94 Suburban motor" was marinized before being installed in the boat. The master techs around here will all tell you what needs to be done to be safe with that motor. Then they might be able to help you with your question, too.

 

[shimano]

Re: OMC ESA operation...

I don't think your esa will work with pointless ignition.I switched to pointless on my 1990 3 ltr.And I found somewhere on this site a fix for that(a couple of resistors and diodes)You actually added it between the - on the coil and the esa.

 

[bruceb58]

Re: OMC ESA operation...

I don't think your esa will work with pointless ignition.I switched to pointless on my 1990 3 ltr.And I found somewhere on this site a fix for that(a couple of resistors and diodes)You actually added it between the - on the coil and the esa.

That is for a Pertronix mod. Sounds like he has an automotive distributor which needs to be replaced by a marine one.

 

[ryanorr280]

Re: OMC ESA operation...

I am thinking that u are correct and I will have to swap distributors to get it to work properly, it would b great if someone could tell me what to do to marinize the engine also, if I can get the shifting working, then I will tackle that, lol

 

[bruceb58]

Re: OMC ESA operation...

First thing is to replace all the casting plugs(aka freeze plugs) with brass ones but that will require removing the engine to do. Might be easier to just put in closed cooling if it hasn't been used too many hours yet in salt water. Also, the head gaskets need to be replaced.

 

[ryanorr280]

Re: OMC ESA operation...

thanks, i will do that once it get the thing to go into/out of gear more than a few times in a row, lol

 

[carolynrose]

Re: OMC ESA operation...

One thing will really help shifting is to make sure the engine idle is between 500-600rpms when fully warmed up. Take the boat for a long ride and get it all blown out and warmed up. Then stop and put it in neutral immediately and set the idle. OMC Drives are tough to shift out of gear so the key is to have them idled way down.

 

[bruceb58]

Re: OMC ESA operation...

Nothing is going to get the ESA working until he gets rid of the automotive distributor that he has on there.

 

[ryanorr280]

Re: OMC ESA operation...

i have played with the idle, and got it down into that range, got it so that it would shift into gear, but somethimes it would, sometimes it wouldn't. then it quit coming out of gear, figured out that you could kill the engine and it would slip right out, so that is when i discovered the ESA stuff...

bruceb58, not to argue, but why will the esa not operate with an automotive distributor? according to the diagram i have it looks like it sends a signal to the coil, but i don't see where the distributor ever actually controls the esa, just trying to learn this stuff. man it is confusing!

 

[bruceb58]

Re: OMC ESA operation...

Why don't you post a picture of the coil and distributor that you are using. The ESA works fine for a points ignition.

Even if you do get a marine distributor, if it is a pointless distributor, you may have to go to an alternative setup like what mercruiser uses. You would use the same switches you have now but they would only be used to ground out the coil.

 

[ryanorr280]

Re: OMC ESA operation...

i haven't posted a picture due to the fact that the boat is uder the carport, and has the cover on. i haven't gotten home before 8 pm yet this week, so i haven't had time to un-tarp it, and get a pic.

it is a non-points system though, GM HEI, like most used in late 80's pickups, has the coil on top of the distributor cap, bolted to it, under a plastic cover. only one power wire coming into the coil.

 

[bruceb58]

Re: OMC ESA operation...

Well...that distributor has to go so no point in making it work.

 

[Black as]

Re: OMC ESA operation...

Would it work if he wired it up the Merc way

 

[bruceb58]

Re: OMC ESA operation...

What's the point? Even if he could that distributor is an automotive distributor and needs to be replaced.