Volvo 5.0gfi High RPM Problem

Just a quick thought. did you buy this boat new or used? and if used was it origianlly sold to someone at a different elevation so that the carbs might be jeted to a different elevation then your current one.
 
Doc;

if you have a gxi engine, there is not a carburator, that is a fuel injected motor. if your voltage to the computor is low you will have some malfunctions. this could explain the rich idle and the top end being missing. my guess is you need to get an electrician out to find the problem. this is consistant with both motors being out of whack. the isolator could be bad, more likely the connections on it are corroded or the tips on the connecting cables are bad. my guess is that your root cause is entirely electrical. I would contact Volvo directly unless your mechanic is a Volvo Dealer. they will probably have some guidence on trouble shooting with the info you have provided.
 
quote:
Originally posted by regal292

Just a quick thought. did you buy this boat new or used? and if used was it origianlly sold to someone at a different elevation so that the carbs might be jeted to a different elevation then your current one.

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Used, but relatively same elevation. The boat was in salt-water near Charleston, SC before moving up to my neck of the woods in Charlotte, NC...but no carbs as it's fuel injected. :) Thanks!
 
This thread has been very informative for me . I have twin 5.0 GXI and have experienced similar performance issues. On one trip out, after the Port engine went into "protection mode" the starboard engine also cut off several times. Fuel right? Fuel was fine, just like your boat. I never thought of an electrical problem. I will check that. I have noticed that the port volt gauge is reading barely at 12v. This occured right before the engine went into protection mode. You are fortunate to have access to a Volvo mechanic. We have very few Volvo certified mechanics in my area. The delay is several weeks. I would love to call someone and have them come right out. The good news is, I am really learning a lot about my boat.
quote:
Originally posted by greendoc

Update:

My mechanic went for a drive and the fuel flow meter showed absolutely NO problems.

An interesting problem with the Regal 292's 12v battery system was the voltage. The readings we were getting were around 11.5-12.3v always on my boat, which seemed kinda odd. If you checked voltage at the alternator and BEFORE the battery isolator, you would get 13+ volts as you should.

Anyways, we re-wired the batteries around the battery isolator and were able to get the system up to 4600rpm and 40.4mph; not bad but STILL seems kinda sluggish for twin 5.0gxi volvo pentas on the 29 foot 292 commodore.

QUESTIONS for everyone though:

#1) What experience do you have with TOP performance on 29-30 foot regals in regards to speed and RPM - please list model # and year when answering unless you happen to have stats for my 1999 Regal 292.

#2) Anyone else had any problems with the factory battery isolators?

#3) Does anyone know how to 'LEAN' out the fuel mixture at idle; it just runs too rich and I don't know if their is a way to change that.

Thanks for the continued responses!!

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Volvo will not help you troubleshoot anything. Don't even waste your time.

42-45MPH is what you should be getting out of the boat.
 
Just a thought, are you using "Deep Cycle" batteries as starting batteries? The Owners Manual states in Bold Type that Deep Cycle batteries will cause problems if used as starting batteries in the EFI engines. I've tried to get clarification on the type of problems which might be caused but as of this post, no luck yet.
 
Originally posted by NAWTICAL1

This thread has been very informative for me . I have twin 5.0 GXI and have experienced similar performance issues. On one trip out, after the Port engine went into "protection mode" the starboard engine also cut off several times. Fuel right? Fuel was fine, just like your boat. I never thought of an electrical problem. I will check that. I have noticed that the port volt gauge is reading barely at 12v. This occured right before the engine went into protection mode. You are fortunate to have access to a Volvo mechanic. We have very few Volvo certified mechanics in my area. The delay is several weeks. I would love to call someone and have them come right out. The good news is, I am really learning a lot about my boat.
Try disconnecting the battery isolator and rewiring the batteries around it from the alternator to the chargers. This increased our voltage from 11.8-12.3v to 13-13.5v almost immediately and also boosted top end power from 37mph to 40.4mph and 4200rpm to 4700-4800rpm. Although, from what i've been told, even at lower voltage, if the engine starts then the fuel injection has enough power and that's not an issue.

Although I would still check your batteries - mine were really low on distilled water and that helped some but I may need to replace them.

I spoke with a V/P mechanic at my dealership today (not my usual mechanic) for some additional thoughts and he said #1) bottom of boat is possibly fouled which can cause 500-1000rpm loss and 10+ mph off the top end, #2) he will check with V/P on idle mixture adjustments, #3) battery isolator is probably not the problem, but batteries quite possibly are.

Hope this helps!
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Doc,

I had a low voltage issue when I first purchased the boat. I traced it to a lose ignition wire. That lose connection caused a lot of problems.

What two locations did you conduct the voltage test? I will check the output at the alternator. Where is the second location you checked for voltage level? Was it the same as the alt?

After reading Pleasure Times post, I will also check my battery type. I have EFI engines and was not aware that deep cycle batteries can cause problems.

Thanks for the post.
 
OK Guys,

I have tried everything recommended in this thread and the repair manual. I have a mechanic coming out tomorrow. I would like to know if anyone has any other ideas that I can discuss with him.

To recap, the engines are Volvo 5.0 EFI Duoprops. They start up fine and purr along until I try to get on plane. Around 3000 RPM the Port engine goes into protection mode. If I continue to push the power the starboard follows and has the same symptoms.

Thus far I have checked:
Fuel, spark plugs, voltage (at battery and ignition switch)I disconnected the tach, all to no avail. I also purchased a diagnostic scan tool. No code faults were stored in the engines memory. The mechanic advised that certain problems will not register a code fault.

There has to be some common problem,the port engine acts up first but the starboard engine follows.

Any one hear of this?
 
How did you check fuel?
What do you mean it went in to protection mode....did it alarm?
 
I pulled the fuel filter. The gas was fine. I only have one fuel tank to draw from. The engines run fine under 3000 RPM and the genny runs fine all the time.

No Alarms sounded. Volvo engines retard themselves when a problem is detected.( do mercs do this?) The computer retards the fuel pump out put. I have owned the boat for a year. The engines have retarded on several occasions. Most of the time it goes away and I never know what caused the problem. This time it wont reset.

Thanks.
 
I thought about that but what would the odds be that both fuel pumps would fail at the same time? Besides, the starboard engine is fine until the port starts to sputter. Only then does the starboard engine retard.

Since it not bad gas, the electrical system is the only other link between the two systems.
 
Are you running your batteries combined or seperate?

I don't see how the electrical systems are linked.

Did you try a new battery yet? The engines are really sensitive to voltage.
 
quote:
Originally posted by regulator

Are you running your batteries combined or seperate?

I don't see how the electrical systems are linked.

Did you try a new battery yet? The engines are really sensitive to voltage.

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The port batteries are connected. The voltage is fine.
The engines share certain ground and power connections on the instrument panel.
 
Run your batteries seperate (not combined) and see if it still happens. I had a bad battery cause these types of problems once on my 5.0 GXI's.

It could still be the fuel pumps, as well.
 
nawtical;

do you have a battery for each motor and a house battery? or pair that double as the house bank? if the later, can you isolate one to each motor?

a very simple test is to get a load tester to each battery and see its present condition. if the batteries check out, you probably have a corrosion/ground problem somewhere. if the later you can run it down yourself with a considerable effort or track down an marine electrician and make your life easier.
 
Regulator, Vic,

Thanks for the input. I did not conduct a load test on the batteries. I only checked the voltage. I have two batteries connected that supply the house power and port starting. I have a separate battery for the starboard.

A defective battery makes sense. All indications point out to some type of electrical issue.
 
nawtical

try the load test first. if you have a single battery with a problem but it is affecting both engines, verify that the batteries are truely isolated by the bridge relay, battery selectors or that the isolater itself has not failed.
 
This problem is like the engizer bunny. Keeps going. I have now changed the batteries. To know avail.

The mechanic came out and advised it was a fuel related problem. The engines sound like they are starving for fuel. When he pulled the starboard fuel filter it was only half full.

I blew out the fuel tank vent hose and found no problem. I double checked the fuel tank and it is half full. The only thing left is to blow out the pick up tubes to see if they are clogged. Any other suggestions are certainly welcome.
 
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