Cobra OMC 4.3 Power Loss

[lstark5386]

I have a 87 Sunird with a OMC 4.3L. Prior to getting it on the lake I put a new set of plugs in and got it running real smooth in the driveway. I took it out and all went well until I opened the throttle. The engine bogged down and now runs rough at idle. There is no power at full throttle and feels like it is missing.<br /><br />I have drained and replaced the gas, changed the fuel filters, rebuilt the carburetor, replaced the points, condenser, rotor, cap, plugs, plug wires, pulled and inspected the distributor, checked the timing, pulled the valve covers off and made sure the values were openning, checked for vacuum leaks. <br /><br />Any ideas what could be causing my problems?<br /><br />Thanks

 

[Boatin Bob]

Re: Cobra OMC 4.3 Power Loss

Check your ESA...sounds like it may be energized and this will definately cause it to miss, there are 2 switches by the shift arm and the module itself. You can unplug it temporarily to test but it should be working to help with shifting out of gear.

 

[lstark5386]

Re: Cobra OMC 4.3 Power Loss

Thanks, I have tried disconnected the switch and found no improvement.

 

[Boatin Bob]

Re: Cobra OMC 4.3 Power Loss

Disconnecting the switch will only prove out the switch, you also need to unplug the ESA itself where the wires go to the coil to totally remove it incase the module itself has gone bad.

 

[lstark5386]

Re: Cobra OMC 4.3 Power Loss

I have disconnected it at the coil. Still no improvement. Thanks!

 

[JustMrWill]

Re: Cobra OMC 4.3 Power Loss

I was having a simular problem, about 3/4 throttle and I would lose power. Rebuilt card over winter...if it ever stops raining will be able to see if improvement.<br /><br />One earlier post on same issue said that the anti-siphon valve on the tank was the problem. Carb not getting enough fuel.<br /><br />Keep us informed.<br /><br />-JustMrWill