95 omc cobra 5.0 wont plane, stalls at 4000

[Maclin]

Re: 95 omc cobra 5.0 wont plane, stalls at 4000

I am remembering issues with spark crossfire with that particular engine. Sorry cannot remember the exact solution but seems like better plug wires and some "extra" separation at some points in their routing was involved. Might do a search here on that.

 

[bconley]

Re: 95 omc cobra 5.0 wont plane, stalls at 4000

UPDATE: It is the Ford/OMC/Volvo Penta. The model number is gone from the sticker but it does say OMC/Volvo Penta and most of the parts are ford/motorcraft.

Well I changed the ignition pick-up in the distributor, new temp sensor. The only thing that did was make it jump from 1700 to 1400 to 1700 at idle. The hesitation at 4500 is still there. I also put a new ignition control module in and that made no difference at all at either RPM speed. I checked the timing, it almost sputters out at 5 bdc so it is set at 8 bdc with the spout unplugged. If I rev the engine with the control to 2000 and hold it, it runs fine until the sputters at 4500.

I did some checking on fuel, lines, sending units, etc. There are 2 pumps. One is on the front of the engine just above the separator. The other is on the top rear of the engine. The first sends fuel to a "box" where a vacuum line and the other sending unit is. The second sending unit sends fuel to the fuel rails. There are 2 Schrader valves to check pressure. One is on the fuel rail, after the second pump. The other is on top of that "box" on the rear of the engine. I have pressure on the fuel rail but not on the "box"?

I don't know if I should have pressure there or not or if that box is like a bowl in a carb and just holds fuel for the second pump. I am almost to the point where I would rather sell the boat.

I have new 8mm wires and that did nothing either. New plugs, wires, cap, rotor, impeller, water temp sensor, ignition pick-up, ignition control module, and timing set. Did not make a difference in high rpm hesitation. It just gave it an erratic idle. AND PEOPLE WONDER WHY EVERYONE HATES FORD...

Oh and the coil stays cool to the touch no matter how long the boat has been running.

 

[bajaunderground]

Re: 95 omc cobra 5.0 wont plane, stalls at 4000

Is it the original motor for the boat?

The Ford ECM's are known issues for that set-up. As I suggested earlier, find a Ford specialist and have them take a look at the OBD? I would say you replaced all the replaceable maintenance items so then if you're sure it's not the fuel/fuel delivery nor the coil, then I would suspect an issue with either compression or or the ECM? Also, the fuel pressure should be throughout the "system" as there's no "bowl" like a carburetor.

Go to Boatinfo - OMC 1986-1998 Service Manual page 284...

I will say the recommended WOT range for that motor is 4,200-4,600rpms, so as far as performance and WOT goes, at least you're in the sweet spot.

 

[bconley]

Re: 95 omc cobra 5.0 wont plane, stalls at 4000

Yea that's how I diagnosed the Ignition pickup in the distributor. And that is what it was. It sent a fault and put the engine in a limp mode. Using a scanner to remove the code did not help. We had to remove the code then disconnect the battery for an hour to reset it and now there are no issues.

 

[bajaunderground]

Re: 95 omc cobra 5.0 wont plane, stalls at 4000

Yea that's how I diagnosed the Ignition pickup in the distributor. And that is what it was. It sent a fault and put the engine in a limp mode. Using a scanner to remove the code did not help. We had to remove the code then disconnect the battery for an hour to reset it and now there are no issues.

good news! The bright side of trouble shooting by throwing parts at issues...you have a complete tune-up for the year!

 

[SinaCobra5.0]

Hey guys, I might be having the same issue. Just bought a new seaswirl spyder, 1993 OMC cobra 5.0. The boat sat for awhile, I took it out a week ago for the first time and it ran great, no problems. The second time i took it out, it hits 1800rpms and jerks back down then back up to 1800 rpms, like there is a rev limitor or something. So I can't get it past 1800rpms. I'm going to install a new fuel filter, I'm also going to change the plugs, but I can't find any possible way to replace the plugs without having to take off the exhaust manifold. Is there a way to erase the code without taking it to a shop?

 

[Sparkinator]

http://www.4shared.com/office/Xo9K__s-/HU_Ford_MFI_7788852.htm

Here is a link to a downloadable service manual for a Ford EFI volvo/omc. It's actually for a 95 HU, but I would think there wasn't much changes to a Ford EFI over those years.

Thanks DonS.

 

[bconley]

There are only 2 things that send the engine into limp mode. Water temp and oil pressure. It's usually the oil pressure sensor, there are 2 of them. They have tan wires with a black stripe. These w into the ecm. Cut the tan/black wire and reset the computer by removing the battery. That's what finally fixed mine. Everyone always blames fuel and fuel filter as a default. If it works after you cut the wire and reset it you know it is one of the sensors.