Volvo Penta 5.0FIPNCSCE SLOW mode

[JTown12345]

Hello!

First off- Replaced impellar, flushed system, tested with IR gun and both engines reading 155 at 3500 RPMS. Cooling doesn't appear to be a problem.

Wondering if it was bad fuel as the culprit (barely used the boat for 2 years) both engines running a little rough after replacing fuel water separator

Port engine running rough at idle and will enter safe mode after being out for awhile.

Wondering if oil pressure/sender switch fooling the ECM. I probably added the wrong sensor and breaker because it's a 96 and parts are EXPENSIVE.

Volvo lists one part as a pressure/sender and the other as a breaker. Which one makes the oil gauges function, which one could possibly trick the ECM?

The pressure/sender is part number 3857532
The breaker is listed as part number 3854181

Thank you in advance!

 

[Horigan]

The SLOW system uses separate temperature and pressure SWITCHES that are independent from the sensors (senders) that go to the gauges. I suspect the breaker is the switch. I believe the switches are normally closed (ECM sees ground) during normal operating conditions, but I'm not sure. If you put a sender in the switch position that would be seen by the ECM as a open circuit and trip the SLOW criteria.

 

[JTown12345]

That's what I was afraid of! The breaker is 170 dollars and there's no Sierra or other aftermarket part. I'll switch the port and starboard breakers to see if it has any effect before purchasing another at that price.

It could still be a cooling issue for all I know in the end but the gauges don't reflect that.


So the RPM's jumping around even at idle. Could that be a faulty switch, bad gas, spark plugs? I've replaced a lot of things, but safe mode leads me to believe it has to do with the oil or cooling system per volvo guidance.

Ty for your input, sir!

 

[JTown12345]

So I disconnected the oil breaker and no change.

Now maybe I'm thinking a bad Air Charge Temp Sensor?
It runs rough at idle and always kind of has since I bought it.

Hardin Marine - Air Charge Temp Sensor Volvo 3854158

Air Charge Temp Sensor Volvo 3854158

www.hardin-marine.com

 

[Horigan]

Try grounding the oil pressure switch (breaker) connector to ground and see if you can get above 2500 rpm smoothly.

It sounds like it's something else. Can you use a portable fuel tank of fresh fuel?

 

[JTown12345]

Try grounding the oil pressure switch (breaker) connector to ground and see if you can get above 2500 rpm smoothly.

It sounds like it's something else. Can you use a portable fuel tank of fresh fuel?

That's a good idea, I read something similar on another post where a boater was having a similar issue. I just ordered the sensor and itll be here next week. I'll go ahead and give that a try.

The boat runs well for a trip around the lake and then it just goes into slow mode. Now it's sitting at the dock running rough idle and the RPMs randomly jumping up briefly.

Now that I've kind of ruled out oil and cooling, maybe next logical steps are fresher gas and the sensor. I mean I have gas in there that's probably 3 years old even though it was properly winterized.

 

[alldodge]

Wondering if it was bad fuel as the culprit (barely used the boat for 2 years, edit: post 6 list 3 yr) both engines running a little rough after replacing fuel water separator

Port engine running rough at idle and will enter safe mode after being out for awhile.

Welcome
Your motor has a ignition module but not a ECM, has carb. Don't see it going into any kind of safe mode, but may retired timing "if" it has a knock sensor. Don't see a knock sensor with the brief look over the parts

My guess is you have a fuel issue, and once fuel goes bad it cannot be fixed with additives

 

[JTown12345]

Welcome
Your motor has a ignition module but not a ECM, has carb. Don't see it going into any kind of safe mode, but may retired timing "if" it has a knock sensor. Don't see a knock sensor with the brief look over the parts

My guess is you have a fuel issue, and once fuel goes bad it cannot be fixed with additives

Thank you, Dodge! I saw you give feedback to another member and was hoping you would weigh in!

I still have half a tank of gas in there in a 75 gal tank. Should I add more fuel or try to have it drained first? Sounds expensive haha!

Did you see my post about the Air Charge Sensor? What are your thoughts on that?

Thank you for your time, I really appreciate this, this has been an issue for a couple years now, although I barely did any boating last year due to wife's surgeries and what not.

 

[alldodge]

Adding good gas to bad gas just makes more bad gas. If it is bad it needs to be drained and maybe used in a lawn more if it's not to terrible

Take the filter off and pour contents into a clear container. The gas should be crystal clear and not smell like anything other then gas

 

[JTown12345]

Side thought- same gas in both engines and the other engine runs fine. The problems w the other engine seem to be intermittent. Not sure if and how that factors into fuel quality.

ty captain!

 

[alldodge]

With other running fine off same gas then look at the carb, probably clogged up a bit

 

[JTown12345]

It's fuel injected, actually 5.0FI Volvo Penta.

 

[alldodge]

It's fuel injected, actually 5.0FI Volvo Penta.

Well, looks like the parts manual shows different
https://www.volvopentastore.com/Mar...on_id.325411975--store_id.366--view_id.765138

If you look at the link it list 5-0FIPNCSCE, then select fuel syatem and it shows a carb

Guess I need to revert to my saved info on my computer
Fuel pressure 31-39 psi
Looking at manual, will get back

 

[JTown12345]

Well, looks like the parts manual shows different
https://www.volvopentastore.com/Mar...on_id.325411975--store_id.366--view_id.765138

If you look at the link it list 5-0FIPNCSCE, then select fuel syatem and it shows a carb

Guess I need to revert to my saved info on my computer
Fuel pressure 31-39 psi
Looking at manual, will get back

Their website is a little confusing. When you look under the picture it has the engine listed under it, if you click the wrong picture it takes you to the wrong place.

For one it shows the engine as having a coolant system but mine clearly doesn't haha!

When you clicked on fuel system, look under the pic, you'll see these engines:

For: 5.0FLPNCA, 5.0FLPNCB, 5.0FLPNCM, 5.0FLPNCS

 

[alldodge]

Looks like Horigan was leading you in the right direction
Without checking for codes we're guessing
The oil and temp switches should be able to be un-plugged. If on of them is grounding out (telling ECM to SLOW) this will show all good to ECM

 

[JTown12345]

I went to the marina and unplugged the breaker today and the rpms still jumped around. In addition the cooling system is all good per the gauges and temp gun.

As I came back to the marina after SLOW mode started, the RPMS were still kind of all over.

I'm wondering if it's that air sensor at this point on the throttle body.

 

[JTown12345]

I didn't even think to check/replace the Ignition coil or the

Amazon.com

https://www.napaonline.com/en/p/SME187492

I just have to figure out if I have both or one of these and where they are ha

 

[alldodge]

It's very rare to have a coil go bad. Folks replace them all the time with no change

With rpm's all over the place maybe the Tach is an issue. Disconnect the gray wire on back of Tach

 

[JTown12345]

It's very rare to have a coil go bad. Folks replace them all the time with no change

With rpm's all over the place maybe the Tach is an issue. Disconnect the gray wire on back of Tach

I hear you, and that's exactly why I'm hesitant to start breaking things down and replacing air sensors, coils, wires, whatever because it could be something else entirely!
I will add it's not just the RPM's all over at idle- After my last outing it first went into SLOW mode, though it also seems there's sluggish acceleration and the RPM's jump around even then. Is it a result of slow mode or something else? Hard to say! We don't have any volvo mechanics around us otherwise I'd get a reading somehow and work with that. I just have to work down the chain of what I THINK is a culprit.

You're not suggesting the tach is affecting the ECM are you?

 

[alldodge]

If the Tach is causing the motor to miss then the ECM might think something else is happening