Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

Reny's Ride

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I have seen several helpful threads on this topic and am still needing help. I would be very appreciative of any recommendations for what to try next.

The Problem:
My 1996 Four Winns Horizon 200 5.0L MFI began surging last summer while driving it on the lake. It consistently surges at 2800 to 2900 RPMs making it unable to increase beyond that range. The best description is it is acting like a governor is kicking in at that RPM range (constant, relatively fast surge).


What has been tried:
  • Pulled the fuel filter and saw that it had water in it. Replaced the fuel filter - no change
  • Added fuel treatment to help remove water, replaced filter again - no change
  • Took it to a dealer to get it repaired (since I was told they were the only person in the area with the correct code reader). They checked it with their (MCI?) computer code reader and said it didn't show any codes (I asked if it was overheating and putting it in Limp mode and he said it would have shown as a code on the computer). There are no buzzers / alarms going off to indicate overheating as well.
  • They checked the fuel pressure and it was good on both the low and high pressure pumps
  • They checked the spark plugs, distributor cap, and rotor and said they were all good
  • The dealer now thinks it may be my ECM (computer) constantly stuck in "governor" mode but it still isn't showing on the code reader.


The dealer is looking for another computer and said the only one they could find is new and will cost $1600.

  • Any suggestions on what to try next before replacing the computer?
  • Is it possible to send my computer off and have it reprogrammed vs. replaced?
  • Any suggestions on where I might be able to find a good used computer replacement?


Is it possible I have water trapped in one of my injectors? I wouldn't think it would only cause the problem at those RPM and it doesn't appear to have any loss of power up to that RPM.

Thank you in advance for your help, I really need it and have been off the water for a majority of the summer!!
 

czopper

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

Did you ever resolve this issue? I have the same issue with the 5.8fi pretty much same motor. Any help would be appreciated.
 

Walt T

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

Surging is almost always a fuel problem. Sometimes mechanics have to put down the readers and actually diagnose. Fuel pressure is a good place to start. Water in the system is an obvious problem
 

Chute

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

Surging is almost always a fuel problem. Sometimes mechanics have to put down the readers and actually diagnose. Fuel pressure is a good place to start. Water in the system is an obvious problem

just stating the obvious; does this model have a pressure regulator on the rail? On my friend's GXi this has a very fine screen which caused problems when clogged even though the pressure test showed good pressure. Just a thought...
 

Dadstir

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

I had a similar problem with my 1996 5.0fi. a couple of years ago. It would run fine up to about 3400 rpm and then surg. I would have to bring it down to almost idle and start all over again. It took me 2 seasons to clear mine up as I only get to hit the lake no more than 4 times a season. I ended up changing the fuel filter a few times added injector cleaner/fuel conditioner, a new thermostat and then a few more fuel filters. Now it runs to 4000 with no surging.
 

Reny's Ride

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

I just got the boat back on Friday of last week. I carried it to a dealer that had the code reader and they didn't fix the problem (they had it from May until the beginning of November). That being said, they earned me as a future customer. They spent a tremendous amount of time trying to repair the engine and had no argument on not charging for anything since they couldn't find the problem.

They tried:

  • New plugs, wires, distributor, rotor
  • Checked pressure on low and high pressure fuel pump
  • Replaced electrical connector on high pressure fuel pump since they thought it might be getting a sporadic / bad connection
  • Checked temperature sensors, replaced one
  • Cleaned all fuel injectors
  • Cleaned fuel tank
  • Replaced fuel filter
  • Contacted Volvo and setup an appointment for them to look at it
  • Replaced ECM
  • Adjusted timing chain, said it jumped a gear

No codes were being thrown and the problem still existed

I had them deliver it to another place near them with an excellent Marine Ford mechanic and he found the problem.

The solution:

He said there are 3 temperature sensors. The one for the ECM was going bad and putting it in limp mode but not throwing a code so the computer didn't know how to handle the issue.


Hope this helps! Looking forward to being on the water in 2014!
 

dypcdiver

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

Great that you found the problem, but lost a whole summers worth of boating.
 

Walt T

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

That will do it. What happens isn't limp mode but the ECM sees a cooler or hotter temp than what is actually there and tries to use that information to fuel the engine. With a MAP sensor and O2 sensor it can really overfuel or underfuel. As long as the sensor isn't putting out a voltage outside of normal parameters there will be no code. In an automobile, a sensor reading too cold all the time can cause the engine to stay in 'open loop' and it will overfuel and have driveability problem while the ECM thinks you're some kind of nut driving around in the freakin arctic. Hopefully while you did lose a season boating maybe the parasites looking for free rides (wife, kids, kids friends, etc) are now bugging the guy down the street who is now seriously considering not draining his block so he too can have a parasite free summer.
 

bruceb58

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

If this was the S.L.O.W mode, there are separate switches(not sensors) for low oil pressure and hot engine temp that will do this. When in S.L.O.W. mode, the ECM modulates the injectors to keep it from going over 2500-3000RPM.

#25 in the following diagram is the switch for temp.
OMC Stern Drive Fuel System & Lower Intake Manifold Parts for 1996 5.8 L 58FBPNCA Stern Drive

#67 is the oil switch.
http://www.marineengine.com/parts/o...OMC+Stern+Drive&section=Crankcase+-+5.8+Litre

You will notice that there is a switch and a sender for both oil and water. The switches only function is for this S.L.O.W mode. They just ground an input to the ECM.

Wish I had seen this thread. Could have saved you a bunch of grief. All you would have had to do is remove the wire from each of these switches to see if it helped your problem.
 
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Reny's Ride

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

Thank you for the information, I am keeping it in case I run into the issue again. It wasn't fun not being able to get out on the water this year but it will make next year that much more enjoyable.

Another question....

After they fixed the problem and took it for a test run, he said it was running up to 5100 RPM and 52 mph. It is my understanding that this boat should run between 4200 and 4600 RPM with a top speed of around 47 mph. The prop is the suggested stock prop 14 1/2 x 21.

Am I at risk of damaging the engine running that high RPM?
What would cause it to run at such high RPM after the repair?

Thank you all again for your help.
 

bruceb58

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

I would double check your tach with a shop tach.
 

Walt T

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Re: Help Needed - 1996 Volvo Penta EFI (multiport) Ford 5.0L surging above 2800 RPMs

No, you don't risk damage to the engine. The drive wont like spinning too fast but 5200 isn't much. Guys like me who have been building marine racing engines for decades 5200 rpm is practically still idling. Seriously though, I would definitely find the correct prop for your boat you will be pleasantly surprised how much better it performs with the correct prop. THAT is why the rpm limits are there. Most definitely verify the tach first before you do anything.
 

Boater_Brad

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Where can i find these three temp senders? I believe i have this exact same issue. Any help is greatly appreciated.
 

QBhoy

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You really need to start a brand new post with your exact engine ID and year.

Agree with this. Unless I have it wrong...I’m pretty sure there wasn’t a multi point injection engine like you’ve described in that year.
Has it been re-engined ? Just perhaps saying this so that poorly can best advise. May be wrong I suppose.
 

KRichmond

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Just wanted to add - to identify limp mode or slow mode it should surge. My 94 Four Winns OMC 5.8 would only rev to 3000 RPM. Motor sounded good, no sputtering or hesitation, just would only go to 3000 RPM. I assumed it was S.L.O.W. mode, so I tested the two water temp sensors/switches, the oil pressure switch, as well as cut the tan wire with black stripe on the ECU. Looks like the tan wire with black stripe was the cheater fix to get these out of limp mode.

This did not fix the problem for me, but after grounding the switches manually, I realized I was not actually in Slow/limp mode. I just assumed I was. My boat had no surging. If it surges around 2500-3000 rpm you are probably in slow mode - check the oil pressure switch and water temp. The tan wire with black stripe could help you out in a pinch, but then you bypass the safeties if you actually have a problem.

My fix, was a Throttle Position Sensor (TPS). Some are adjustable. You can hook up a voltmeter to the sensor wire and get a baseline. Then turn the sensor slightly (you may need a chainsaw file to open the grove in the plastic tabs) Then retest and see if the volts change. I just bought a new TPS for $80.

In short, if your 5.0 ort 5.8 ford doesn't want to go past 3000 rpm from a hole shot, it could be your TPS. If it surges its probably Slow mode. If no surges, then try TPS. I am no expert, just sharing my experience.
 
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