OMC Cobra 5.0L EFI Spudder

[mtbr00x]

Re: OMC Cobra 5.0L EFI Spudder

Maybe it will give you guys some satisfaction to know that I am having the same issue, However my issue is with a naturally aspirated OMC 5.7L Thanks for all the trouble shooting posts I will try what you guys have tried and update once I have done them. One difference is that my fuel has been in the tank for quite some time and I am sure that will be a contributing factor in my problem.

from idle to WOT in neutral everything is great. once I put it in gear i can not "Floor it" I can get up to cruising speeds, WOT even, I just have to move the throttle lever very very slow.

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Talked to a few more people and got some more insight and a few more things to test. One being the TPS and the other Fuel Pressure.

Testing the TPS: I did a static resistance test by unplugging the connector and probing w/ my ohm meter, then moving slowly throught the entire range of throttle ensuring that I had a smooth and gradual resistance variation. And it did. Then I plugged it back in and did a Voltage test w the key On. Measured between ground and the green wire, again moving through the range of the throttle observing the voltage variation. It also looked fine w/ a gradual increasing and decreasing voltage.

So, now I need to move on to the Fuel Pressure, but I have to either go buy a guage or ask around.

I see that there is a thing that looks like a Schrader Valve or a pressure releif valve on the fuel rail, but not sure if that is the right spot for checking the pressure.

Any experience out there w/ this???

Thx - Dan

 

[Rat Capri]

Re: OMC Cobra 5.0L EFI Spudder

I see that there is a thing that looks like a Schrader Valve or a pressure releif valve on the fuel rail, but not sure if that is the right spot for checking the pressure.

Any experience out there w/ this???

Thx - Dan

pressure test port, most auto parts stores will have the gauge you need

 

[Ocean 22]

Re: OMC Cobra 5.0L EFI Spudder

I have not been able to fix the problem despite replacing a host of parts. I did a fuel pressure test and that was normal. The problem is still occuring. I took the boat out this weekend, and the engine on several ocassions did rev up to full power at WOT, however it ran fine on its own. this seems to be some kind of electrical or computer related issue with these engines. Can anyone out there offer some help. I feel that summer will slip by, and i will not be able to get out there very much. I just do not have The $$ to take it to a dealer. Thank you

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

pressure test port, most auto parts stores will have the gauge you need

Okay cool, I'll check that out thanks !

Ocean 22, I feel you pain and frustration, the summer is here is full swing, and all I can do is put-put around.....

I spent a grand last year on the out drive, can't afford to take mine to dealer either.....

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Checked fuel pressure today and it's a-ok.
Did some searching on OBD1 diagnostics for my engine and came across this:
http://www.extreme-check-engine-light-codes.com/Ford OBD1 Decoder.htm

So I went to Walmart and bought a $4.00 12volt tester and followed the instructions for code testing.

Mine has a code # 22 stored which is the MAP sensor out of range code.
I tried running it w/ the MAP disconnected and it ran very rough and set another code, but I cleard that by unplugging battery.

So, I already bought a MAP sensor and it didn't help, but I got it from an Ebay store which could have been a used part?? It didn't come in a factory box.

There is a vaccum hose that connects through a small plastic cylindar to the air intake manafold. I couldn't reach the connection to the manifold to pull and test the line. Might have to remove the entire air intake just to get to it.

I'm going to try the code thing again tomorrow w/ the original MAP sensor on it just incase the one I bought is creating the code.

 

[Ocean 22]

Re: OMC Cobra 5.0L EFI Spudder

I tried the map sensor replacement, but that did not work for me. Someone on another post suggested that our engines are stuck in SLOW safe mode. The person on that post suggested to disconect the wire to the oil pressure sender, and the wire to the secondary water temp sender. then to check if it would run OK. CAN ANYONE OUT THERE GIVE MORE INFO ON THIS SLOW MODE. DOES THE COMPUTER GET STUCK IN THIS MODE? HOW DOES ONE RESET IT?

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

From what I've read about the slow / safe mode is that it limits the RPM to somewhere around 2500 - 2800.

Mine wants to surge at 2500 RPM as if you were pressing and releasing the throttle. Not sure if thats the same the slow mode where I think it just keeps you from going any higher than the limit.

I can increase my RPM beyond the 2500, but then it just cycles the surging faster.

I think having the right scanner that can show you the signal values would be the ticket. But, I'm not sure that they make them for that year and the marine application.

 

[Ocean 22]

Re: OMC Cobra 5.0L EFI Spudder

my engine did actually go into the SLOW mode once when my water pump failed, and the engine overheated. It did the same thing that your engine is doing. I read up on this in the manual, and it states that the computer will interupt one bank of the injectors at above 2800 rpm when there is low oil pressure or a overheat condition, however under 2800 rpm it will run normaly. My engine however will rev up to 2900 rpm and not go any higher under load. However in neutral it will rev up to redline without a problem. This weekend i was putting around at 2900 rpm, and then sudenly the engine decided to rev up and go up to 3900 rpm, but after pulling the throtle back it would not rev up to 3900 rpm. It just continued to be only rev up to 2900. the slow system has two sensors. one for the oil pressure, and one for water temp which located just behind the thormostat housing on the intake manifold. check you wiring to these sensors. it should be a single brown wire to each.

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Well at least its easy to check that wiring, I've seen the sensors and the wires, so I'll have a look tomorrow...

Thanks !!

 

[Ocean 22]

Re: OMC Cobra 5.0L EFI Spudder

Danno, Do you have any further updates?

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Danno, Do you have any further updates?

No, but I'm going to dig back in today and try a few more things w/ the Oil pressure and water temp sensors.

I'll chime back in later.....

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

I put the original MAP sensor back in, tried disconnecting the Oil pressure send wire, ran the same....
Checked for codes, and now I have a 67, and a 12. Before it was a 22....
So, looking down the list I see that there are some codes that only pertain to a car or truck, so I'm thinking that the list has got to be different for the marine app.

Now, where to get a hold of the right list??
4 Winns??, Dealer??

I'm going on vacation for a week, and will putz around when I get back.

 

[Ocean 22]

Re: OMC Cobra 5.0L EFI Spudder

Danno , i checked the factory service manual , codes 67 and 12 are not listed. Code 22 is listed as MAP out of S/t range. What type of scan tool are you using?

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Danno , i checked the factory service manual , codes 67 and 12 are not listed. Code 22 is listed as MAP out of S/t range. What type of scan tool are you using?

Well, the code 22 went away, and I have the others....
I'm just using the method described in that link I posted w/ the codes.
Using a 12V line probe and a jumper to the Self Test pin on the diags connector. I flashes long and short w/ pauses inbetween codes.

Long = 1st digit, short = 2nd.

Maybe I'm reading the flahes wrong????
It seems inconsistant when I run the test.
Perhaps I have a code 6 and a code 7, followed by the 12??

Thanks for the info, I need to get a hold of the right code list for this, otherwise I'm chasing tail.

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Just an FYI: There are no codes below 10. Perhaps this will help you.

That certainly looks like a better list.
Is that for a 93 OMC / Ford 5.0?

Where did you find that?

I've tried fuel injector cleaner, Octane boost, new fuel.
Mine is a MPFI not TBI.....

The trim sensor is a bit unstable, perhaps I'll have a look at that...

Thanks for your help and information....

Danno

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

BTW, what is a NDS circuit? (code 67)

Thx!!

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Ah, very good then...
NDS = Neutral Drive Switch.

Thanks a bunch - I'll have to dig in to the trim sensor when I return from vacation...

Dan

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Okay, I had a chance to check the Trim sensor, I went by the manual that I have and located the sensor, but couldn't locate the 2 pin connector.

First I ran the tilt up and down to observe the range which went from full down to only half way in the full up position.

So, I tried just removing the sensor from its mount, and ran it back and forth to see if I could make the guage go through the entire range and the guage just read 1/2 way without moving at all.

Put it back in the mount, and ran ithe tilt up and down, and the guage is still stuck in the 1/2 way position.

Does anyone know where to locate the 2 pin connector??
I'd like to run an ohms check to see if it moves throught the range on the meter. My manual says 0 - 200 ohms +/- 10%.

I may have to pull the boat out cause hanging over the back on the lift is not going to cut it.

Thx - Dan

 

[Danno5.0]

Re: OMC Cobra 5.0L EFI Spudder

Oh, and I ran another code check, and it still flashes a 67, and 22.
But I'm not sure thats entirely correct. The 67 flashes twice in a row by a steady 6 flashes followed by a 7. But the flashes are the same length.

I though the 1st digit was a long flash followed by a short flash.

Then it pauses, flashes a long 1, followed by 2 short then 2 short again.
It does not repeat the 2nd code.