4.3L HO OMC Cobra problems

[BiONetworks]

Re: 4.3L HO OMC Cobra problems

hmmmm. Well we did some checking looks like all the gm modules are needing the ecm to even function period. Ill post a parts list of parts needed to convert back to dist setup. Cost is around 600-750 Retail and the parts are becoming scares. I know theres only 1 main wiring harness for the dist. style left in the usa, ITS MINE .

 

[pra51]

Re: 4.3L HO OMC Cobra problems

Biohazard<br />It can be done with out that wiring harness.A guy I got info from did the conversion with a aftermarket hei marine dist.I also have a link to a company that is making esa's for these systems.I will send all that to you this evening,including the dist. he used.<br />Could you possibly send me that diagram also that you recieved?<br />Phil

 

[Lou C]

Re: 4.3L HO OMC Cobra problems

Hope it all works out, we OMC junkies have to stick together!!

 

[BiONetworks]

Re: 4.3L HO OMC Cobra problems

roger that, i finally got my clymer manual in. I was flippin threw found the module has a built in safety system for the oil pressure and water temp that kills the motor down to 2800rpm until you restart it, which mine was was doing. We are going to try to attempt to disconnect the sensors and see if it runs. One of them might be false tripping, well see. ill keep ya updated.

 

[BiONetworks]

Re: 4.3L HO OMC Cobra problems

Oh and yes phil i can send that to you just gime your email adress and ill get it over to you. Its for a 1990. My motor apears to be a 1991 or a 1992. but the diagrams apear to still be the same.

 

[pra51]

Re: 4.3L HO OMC Cobra problems

Biohazard<br />I am going to email the link to the HEI self contained distributor and the infor on the company that makes esa system for marine shifting applications to your email address that you gave above.This will also give you my email address to use.By the way the problems I am having with my spitfire is.It starts great runs great.Boat will do 54 mph by gps.Never misses a beat.I stop and wait a hour or so and I have no ignition,just crank and crank.I replaced the timing sensor which several people had thought was the problem but did not help.After cranking for 4 or 5 mins,just all the sudden it has fire and runs great till you go through the process again.<br />Phil<br />Phil

 

[BiONetworks]

Re: 4.3L HO OMC Cobra problems

the ignition module was definatly a faulty problem. after they tried using it in 1990-1992 in 1993 they replaced it back with distributer. Ill get back to ya later today when i get some time. Ill see if some of the techs know about it.

 

[BiONetworks]

Re: 4.3L HO OMC Cobra problems

Oh and email me again phil so i can send you that diagram, i have it here at work but not at my home. Im looking at the cdi electronics book right now i do see that **** assist, which apears to be made for the pertronics conversion kits ill have to do a little more research into this though.

 

[pra51]

Re: 4.3L HO OMC Cobra problems

Biohazard<br />Any good progress on your cobra?

 

[Juancho]

Re: 4.3L HO OMC Cobra problems

Boatin Bob,<br /><br />Could you please send me a copy of the wiring diagram as well. My 1990 4.3 HO has started kicking into limp mode for no apparent reason. I think I am going to start my trouble shooting by replacing the temp switch and the oil pressure switch, but I would like to have a wiring diagram, so I can check all the wiring as well.<br /><br />Thanks,<br />John

 

[Boatin Bob]

Re: 4.3L HO OMC Cobra problems

Sure John...just need an email address to send to

 

[lakelivin]

Re: 4.3L HO OMC Cobra problems

Gentlemen,<br /><br />Any chance of posting images of the diagram in this thread for future reference for others? I think you need to store images on something like photobucket or myfishingpictures.com, but might be useful to capture as much info in this post as compared to passing it back & forth via private email.<br /><br />Just a thought....

 

[Boatin Bob]

Re: 4.3L HO OMC Cobra problems

I'm trying to post the image here but can't so here is a link to my photo album where I put it 4.3 HO Wire Diagram

 

[marinemech1]

Re: 4.3L HO OMC Cobra problems

sorry to say but get rid of that spit fire system yamaha also used this set up but it is quite un reliable.<br />order a distributer, shift esa ,switches ,and wire harness from a 4.3 low output model (may need to buy some other pieces)<br />p.s. long before bombardier entered the marine (outboard) business omc stern drive division was purchased by volvo/penta

 

[Juancho]

Re: 4.3L HO OMC Cobra problems

Thanks for your help boatin Bob. <br /><br />Biohazard,<br />What ever happened with you spitfire ignition problem? Were you able to just disconnect the water temp and oil pressure switches? Will it still run with these two switches unplugged? My 4.3 HO is intermittent going into limp (S.L.O.W.) mode. I am not sure whether it is the computer brain, the water temp or oil pressure switch or a short in one of the wires? Not really even sure where to start.

 

[Boatin Bob]

Re: 4.3L HO OMC Cobra problems

Just going to try and post that image one more time <br /><br />Hey it worked!!! <br /><br />

 

[Juancho]

Re: 4.3L HO OMC Cobra problems

Thanks Boatin Bob this is much better than the wiring diagram in my OMC manual.

 

[Juancho]

Re: 4.3L HO OMC Cobra problems

I think I may have found a work around for the problems I have been experiencing with my spitfire ignition. Lately my OMC 4.3 HO has been intermittently dropping in and out of S.L.O.W. mode for no apparent reason. Engine temps are fine and oil pressure looks great, but the engine still continues to go into limp mode. <br /><br /> I have done quite a bit of research on the subject, during which I realized that Evinrude outboards use a similar electronic ignition system. I found a great troubleshooting article which described how to disconnect the sensors to try and eliminate them from the equation. I disconnected both the water temp switch and the oil pressure switch and then I test ran the engine with water muffs. I wasn’t able to bring the motor up to speed for more than a few seconds at a time, but no more S.L.O.W. The real test is yet to come, when I can get it back out on the water. <br /><br /> The nice thing about this work around is that the water temp and oil pressure gauges still work. The S.L.O.W system uses separate switches. So I can leave the switches disconnected indefinitely as long as I keep my eye on the gauges.

 

[Boatin Bob]

Re: 4.3L HO OMC Cobra problems

Juancho....sounds promising...please post back with your water test results...good luck!

 

[Juancho]

Re: 4.3L HO OMC Cobra problems

Well...unfortunately my experiment was only half way successful. The engine runs with both the oil pressure and water temp switches disconnected, but it runs in limp mode the whole time.<br /><br />However, I did also notice the engine on the whole ran a lot better with the switched unplugged, It idled smooth as silk, which was never the case before. As soon as I reconnected both switches, the engine started to run like crap. Not only would the boat go into limp mode, but also the engine would start to cut out entirely. <br /><br />I am now pretty sure, that the switches are to blame, but even just the switches are impossible to come by for this one-off powerplant.