'97 OMC COBRA/Volvo 350 EFI

[Robinero]

'97 OMC Cobra 350 EFI power loss at about 2700-3000 RPMS.
I have had the boat in the shop over a month and they first diagnosed it with a clogged fuel filter. As soon as I hit the water the same problem persisted. I can throttle up gently or quickly does not matter. When I throttle gently the boat engines creeps up to about 2700 RPMs power drops off and if I leave the throttle alone eventually the engine will power back up again. Also, after the power drops off I can here a squealing sound in the engine similar to a belt squealing but not as loud. The shop is now suggesting to replace the ECM. Very Expensive and I'm not convinced that is the problem. Any ideas?

 

[Don S]

Re: '97 OMC COBRA/Volvo 350 EFI

What is the FULL model number of your engine. Need all the letters.

 

[Robinero]

Re: '97 OMC COBRA/Volvo 350 EFI

Does T0813274 Makes sense. This was on the bill of sale. The boat is in the shop. They are calling it a Volvo/Penta 5.7 GI. I have a call in to see if they can provide a complete Model#. BTW They are now telling me the ecm needs to be reprogrammed . If this is accurate can you advise me where I could have this done.

 

[Don S]

Re: '97 OMC COBRA/Volvo 350 EFI

T0813274 is an OMC number, not Volvo. This is an engine put out by OMC during the joint venture.

BTW They are now telling me the ecm needs to be reprogrammed

Is your shop a Volvo or OMC dealer? if not, you need to find a real dealer. Your shop sounds real suspect to me, and without knowing what they did to determine what was wrong, I can't say for sure what the problem is.

 

[Robinero]

Re: '97 OMC COBRA/Volvo 350 EFI

I do not know how they diagnosed the problem. However, I can tell you the owners manual I have says OMC stern drive on it but the lower unit says Volvo. Im not sure if I need to find a Volvo dealer or a OMC Dealer (who I understand no longer exists.) The shop is who the previous owner used since the boat was new. I dont think they are a dealer for either brand. The closest one I have found to me is 2 hours away. I have read that an ecm either works or it doesn't. All I know is that I'm being told that I am looking at 2000.00 for an ecm. I was hoping there would be a less expensive way to replace it if in fact that is what I need. I plan to haul the boat to the closest authorized dealer. He says that he can send it to Volvo to be reworked but if they are not successful then I'm lookin at 2000.00. Thanks for your response.

 

[Don S]

Re: '97 OMC COBRA/Volvo 350 EFI

If you can't find an OMC dealer, don't be surprised, OMC sterndrive division went out of buisness in 98. Volvo bought them out.
Find a Volvo dealer, they know how to fix it, it's the same as Volvo, just with the OMC name on it.

PS: Moving this to OMC, as it's not a Volvo engine.

 

[Robinero]

Re: '97 OMC COBRA/Volvo 350 EFI

Thanks!
FYI I Started in the OMC forum they referred me to you at this forum.

 

[Don S]

Re: '97 OMC COBRA/Volvo 350 EFI

I follow both forums.

 

[ddbaran]

Re: '97 OMC COBRA/Volvo 350 EFI

Did you check your fuel system? I had a very similar problem with my OMC 5.8L 1994 Fourwinns.
Turned out to be a broken fuel fitting on the tank connection where it was sucking in air. It also leaked the fuel out once the engine was turned off.
So if you sometimes smell fuel after a long run this may be where the leak is causing your problem.

Hope you find the problem.

Dave

 

[Robinero]

Re: '97 OMC COBRA/Volvo 350 EFI

Turns out the problem was a sensor malfunction causing the boat to go into Engine Protection Mode. The oil pressure switch was the sensor that failed.

 

[Idlespeedonly]

Re: '97 OMC COBRA/Volvo 350 EFI

Did the dealer find the problem?

 

[Robinero]

Re: '97 OMC COBRA/Volvo 350 EFI

Yes, The dealer made the repair, however they were looking at the fuel system and I pointed them in the direction of the sensor after reading about a similar issue posted on this forum.

 

[skippy2235]

Re: '97 OMC COBRA/Volvo 350 EFI

So I know there are 2 oil sensors.
which one did they replace?
There is the small one that is just a switch, but I dont know where it goes to.
and there is the big one that I guess goes to the gauge?

 

[Robinero]

Re: '97 OMC COBRA/Volvo 350 EFI

It is my understanding that there is a oil pressure switch and an oil sending unit that sends a signal to the gauge to give you a oil pressure reading
. The switch was the sensor that failed. Oil pressure reading was fine. According to what I have read the switch is optional and may not be on an every engine

 

[Don S]

Re: '97 OMC COBRA/Volvo 350 EFI

This is from the service manual, and may help explain what happened.