1990 OMC 4.3L ESA Problem

[tomnant]

I am experiencing an unusual problem with my 1990 OMC 4.3L ESA. For some reason it kicks on acceleration for a few seconds, causing the engine to bog down. Any suggestions as what may be causing this. The ESA works fine for its intended purpose when shifting.

Thanks

 

[HT32BSX115]

Re: 1990 OMC 4.3L ESA Problem

Howdy,

Your ESA should not be activating at all after you get it into gear. You need to determine if it is. You can do this by having someone observe the actuator (#37) in the picture and see if it's moving after you're in gear and and pushing forward on the throttle.

If it's moving after you're in gear, you have some sort of mechanical problem or a problem with adjustment. It should NEVER move when going into gear. It should move (and the ESA should actuate) ONLY when coming OUT of FORWARD or REVERSE.

Cheers,

Rick

 

[tomnant]

Re: 1990 OMC 4.3L ESA Problem

Thanks for your reply.

The actuator is actually moving when I shift into forward. I had the Shift Cable replaced late last year. If this is not adjusted properly, would that cause the problem ?

Thanks

 

[HT32BSX115]

Re: 1990 OMC 4.3L ESA Problem

Yes. maladjustment could cause it. A defectve, frayed or corroded cable could cause it too.

Have a look at this:---> http://www.hastings.org/~stuart/cobra/

The ESA should never activate when going into gear.....only when coming out, and then only when the drive is loaded by having it in the water.


You also probably need an OEM OMC manual.

 

[Boatin Bob]

Re: 1990 OMC 4.3L ESA Problem

Actually it's ok for it to move going into gear, in the OMC factory manual it says quote" The ESA module will function when shifting both into and out of forward and reverse" end quote. Obviously it's more important for it to work coming out of gear. Does you system have an overstroke switch? Probably item 62 in the above diagram, item 64 should be the interrupt switch. Once in gear the overstroke switch is activated by a cam on the shift arm which prevents the ESA from ever working while in gear (opens the circuit) On the newer ESA's they eliminated the overstroke part and went with a built in timer in the ESA itself.

Are you saying that you are already in forward and moving and then you give it more throttle and the ESA activates causing the bogging down? This could mean that the upper shift cable is moving which shouldn't happen once in gear.

 

[tomnant]

Re: 1990 OMC 4.3L ESA Problem

Thanks

I will check the overstroke switch.

 

[bruceb58]

Re: 1990 OMC 4.3L ESA Problem

Another thing you can do is to unplug the ESA temporarily and run your boat to see if you have the same symptom.

 

[Coors]

Re: 1990 OMC 4.3L ESA Problem

I am experiencing an unusual problem with my 1990 OMC 4.3L ESA. For some reason it kicks on acceleration for a few seconds, causing the engine to bog down.

the engine revs up? or is something slipping? need more info.
The esa kills the ignition circuit; it may be that your throttle cable is binding/trashed.

 

[bruceb58]

Re: 1990 OMC 4.3L ESA Problem

The esa kills the ignition circuit; it may be that your throttle cable is binding/trashed.

it is the shift cable that triggers the ESA, not the throttle cable.

 

[HT32BSX115]

Re: 1990 OMC 4.3L ESA Problem

Actually it's ok for it to move going into gear, in the OMC factory manual it says quote" The ESA module will function when shifting both into and out of forward and reverse" end quote. Obviously it's more important for it to work coming out

I'll have to stand corrected on that one. I guess I was referring to my 1987 King Cobra. It did not actuate going to gear. My service manual also indicated that it actuated when going into gear.

Mine shifted very easily and only actuated when coming out of gear....Maybe it should have actuated when going in.

On another note....The ESA does not "KILL" the ignition. (At least in 1987 it didn't) According to the service manual the ESA "Pulses" the ignition and should cause the RPM to drop no lower than about 500rpm.

The whole point of pulsing the ignition is to cause torque (reduction) pulses so you can easily get the drive to shift out of gear by reducing torque on the clutch-dogs.. It's far more important coming out of gear than shifting into gear.


Bruce, I LOVE that rotating prop avatar!!

Here's mine!!

 

[Lou C]

Re: 1990 OMC 4.3L ESA Problem

I think it is possible that if the transom shift cable is sticky or failing, or the area in the pivot housing where the cable comes out is packed with crud (sometimes water leaks into that area) it can cause the ESA to come on when the engine is in gear, mine was doing that when I first had it. I took it to a good OMC tech and they basically cleaned out that area (esp around the bellcrank in the pivot housing) and made sure the cable was adjusted right and it's been fine ever since.

 

[HT32BSX115]

Re: 1990 OMC 4.3L ESA Problem

That also what the "Over-Stroke" switches are for. Once it's in gear either fwd/rev the overstroke switches are actuated such that even if the cable does cause a little push or pull it still won't activate the ESA....if you still are getting ESA activation once it's in gear then the over stroke cam adjustment needs to be performed (after the shift cable adjustment)..............

Bottom line.....If you are not sure if the lower shift cable has not been replaced in many years it might not be a bad idea to remove the drive and carefully inspect the cable. If there's ANY question about it's condition, REPLACE IT. Defective cables have destroyed many Cobras over the years.

MAN!!! I'M GLAD I DON'T HAVE TO DO THIS STUFF ANY MORE!

I think it is possible that if the transom shift cable is sticky or failing, or the area in the pivot housing where the cable comes out is packed with crud (sometimes water leaks into that area) it can cause the ESA to come on when the engine is in gear, mine was doing that when I first had it. I took it to a good OMC tech and they basically cleaned out that area (esp around the bellcrank in the pivot housing) and made sure the cable was adjusted right and it's been fine ever since.

 

[bruceb58]

Re: 1990 OMC 4.3L ESA Problem

I think it is possible that if the transom shift cable is sticky or failing, or the area in the pivot housing where the cable comes out is packed with crud (sometimes water leaks into that area) it can cause the ESA to come on when the engine is in gear, mine was doing that when I first had it. I took it to a good OMC tech and they basically cleaned out that area (esp around the bellcrank in the pivot housing) and made sure the cable was adjusted right and it's been fine ever since.

OMC came out with a bellcrank bushing fix that helped alleviate this problem. Basically, you replace the bushing that the bellcrank rides in with one that has a grease fitting on it. What happens is that when you replace your drive, you fill the cavity that the bellcrank is in with grease. This displaces the air in there with grease so that no water can get in and evaporate. This is especially necessary in salt water, as over time, you just get a bunch of white sandy crud in there that hinders the movement of the bellcrank.

 

[Coors]

Re: 1990 OMC 4.3L ESA Problem

it is the shift cable that triggers the ESA, not the throttle cable.

Meant that; I have an 88; replaced the esa module with the newer one, over-stroke not needed, as said. works great.