Volvo D4 fast idle

[AllanG]

When I run my Volvo D4 out of gear, the maximum revs appears to be limited to 1500 rpm, so can anyone let me know how to over-ride this limit so I can check the engine at higher rpm.

Many thanks........& Happy New Year to all!!

Allan

 

[volvopaul]

It is set up like that for a reason, most common rail engines are like that. There is no need or reason to rev the engine out of gear on a no load application, if you had a problem it would show up on the edc. Best try under load w o t in gear at sea and check your getting max r p m .

 

[AllanG]

As usual, very many thanks for the advice, Paul!

Cheers, Allan

 

[Latestarter1]

In addition to Volvopauls input high idle test on elactronic engines becomes redundant as diagnostic tools give you % throttle read out.

 

[Momac]

And, I believe, revving an engine under no load is not good for it.

 

[Latestarter1]

And, I believe, revving an engine under no load is not good for it.

Absolutely wrong!

Mechanical diesel engines have no issue running out on the governor droop. Standard test shop practice is to take warm engine to high idle and let governor stabilise and record all the figures letting motor sing to you before applying dyno test load and giving it some real torture.

Very reason why manufacturers spec sheet contains high idle specification. In order for you to test it.......The only time I have ever been afraid was when I had crawled into very tight space between the crankcase and hull plating and a 38 liter V12 to check that one of the exhaust pyrometers was still connected when the guys on the control flat took the motor to high idle, that was the only time I did not find pleasure in an engine singing to me.

 

[Portofino]

It's 1500 rpm because the boat is not moving forward and thus no water forced through the the tiny inlet holes in the front of the leg .
My kamd 300's (not C rail) also will not exceed 1500 rpm in neutral .
As V Paul says faults will show up on the diagnostic codes
VPenta do a workshop manual for keen owners with the intension of encouraging them do home maintenance costs £ 30 from their website explains all

 

[Spud1973]

Hi Portofino, have you a link for the manual?

 

[PCUK]

I don't think water passing through the leg will in any way affect RPM. It's probably the way the control is set up. Open the throttle manually on the engine to get high idle.

 

[spannerman]

I don't think water passing through the leg will in any way affect RPM. It's probably the way the control is set up. Open the throttle manually on the engine to get high idle.

If you can show me the throttle cable on a common rail diesel I'll rev it up manually!

 

[scottie]

It's 1500 rpm because the boat is not moving forward and thus no water forced through the the tiny inlet holes in the front of the leg .ll

water should come up the large vertical hole bottom of leg at front
Always worth checking for nasties growing inside

 

[PCUK]

Still won't affect revs!
Thanks Spannerman, had a senior moment there!

 

[Portofino]

...Hi the link i hope below for the DIY manuals
you will need engine serial no to ID which one .
I get the impression once out of warranty they seem to encourage us to have go at reasonable DIY and take pride in the the introduction of how many units made / sold world wide eg mine KAMD 300 some 160,000 out there i.am told and V Penta understand -"part of the pleasure of boat ownership by some customers is DIY maintanace" Hmm?
www.volvopenta.com/volvopenta/global/en.../publication_search

The ECU will not "allow" it go above 1500RPM at idle , i guess some sort of self protection.

Wife does not trust me to have go ,We actually get a local VP agent (SoF) to service. How ever the book makes good bedtime reading , and i have changed a snapped alternator belt at sea,and check/adjust the other belts (black dust diesease).In 510 hrs thats all i have needed it for over the past 6y (DPG legs stearrng ram is inside nice and dry)

 

[Spud1973]

Many thanks for the link!

 

[ulyden]

Most marine engine controlls have a input for neutral. This is to protekt cluch or whatever you call it. If you whant to run up the speed to listen for sounds, measuring vibrations, or torsjonal vibrations or whatever, you toggle this svich to allow engine speed to go to maximum.

This has nothing to do if its common rail PLD or PD. Just a safety preventing damage on gear/outdrive.

Also remember that demand speed is important on every engine. If your trottles don't ask for 3500rpm you don't get it. Potensiometer can fail.

If you have a clever controll it detects engine power and understand that your propeller don't rotate or does not eksist.

 

[Latestarter1]

Cannot believe that such a simple subject can develop a life of its own? Lets all get down to worrying about subject over which you have some control, and can be life changing. For example charge air cooler servicing.

As Ulyden commented this is not a common rail 'thing' applies to any engine with electronically controlled governor. The poster who has the feature on a KAD engine has a dumb mechanical fuel pump with a smart electronic governor.

No need to test for high idle on electronic engine as the service tool gives you throttle position and I assume with Volvo % engine load.

Simple agorithim is in the control software makes engine Muppet Proof, prevents going to high idle out of gear, manufacturers have to assume some nutty owner will try it on stone cold engine.

Electronically controlled engines have a far more tightly controlled governor 'droop' some models close to Isochronous. Enables manufacturer to set engines up in such a way that they can optimise performance, far closer to engine 'critical' speeds than any mechanical motor, but at the same time preventing occasional excursion into 'critical' zone.

Visulise.........We used to have throttlemen on power boats, today we can have power boat driver who is (complete airhead), pulling WOT, max tight wire 95% engine load becomes airborne instantly releasing prop from load. In the blink of an eye ECU has dumped rail pressure and cut back fuel.........Vessel hits the water and props calling for 95% load again which is delivered in an INSTANT. Driver sees slight flick of tacho over perhaps 50 rpm range and never gives it a second thought. Engine is never wanders close to 'critical'. Guys who put this control software together are real stars in my book.

 

[stuartwineberg]

Thread Drift

Cannot believe that such a simple subject can develop a life of its own? Lets all get down to worrying about subject over which you have some control, and can be life changing. For example charge air cooler servicing.

As Ulyden commented this is not a common rail 'thing' applies to any engine with electronically controlled governor. The poster who has the feature on a KAD engine has a dumb mechanical fuel pump with a smart electronic governor.

No need to test for high idle on electronic engine as the service tool gives you throttle position and I assume with Volvo % engine load.

Simple agorithim is in the control software makes engine Muppet Proof, prevents going to high idle out of gear, manufacturers have to assume some nutty owner will try it on stone cold engine.

Electronically controlled engines have a far more tightly controlled governor 'droop' some models close to Isochronous. Enables manufacturer to set engines up in such a way that they can optimise performance, far closer to engine 'critical' speeds than any mechanical motor, but at the same time preventing occasional excursion into 'critical' zone.

Visulise.........We used to have throttlemen on power boats, today we can have power boat driver who is (complete airhead), pulling WOT, max tight wire 95% engine load becomes airborne instantly releasing prop from load. In the blink of an eye ECU has dumped rail pressure and cut back fuel.........Vessel hits the water and props calling for 95% load again which is delivered in an INSTANT. Driver sees slight flick of tacho over perhaps 50 rpm range and never gives it a second thought. Engine is never wanders close to 'critical'. Guys who put this control software together are real stars in my book.

Let me take you up on your offer of thread drift - why is air charge cooler servicing so important? As you know from my other thread on overheating, I did this for the port engine and it was a heavy job with a 45kilo lump of metal to take off. What are the implications of not doing it. Finally - wot is WOT - I see it a lot in your threads

Thanks

 

[andy59]

WOT = wide open throttle

 

[ianj99]

Cannot believe that such a simple subject can develop a life of its own? Lets all get down to worrying about subject over which you have some control, and can be life changing. For example charge air cooler servicing.

As Ulyden commented this is not a common rail 'thing' applies to any engine with electronically controlled governor. The poster who has the feature on a KAD engine has a dumb mechanical fuel pump with a smart electronic governor.

No need to test for high idle on electronic engine as the service tool gives you throttle position and I assume with Volvo % engine load.

Simple agorithim is in the control software makes engine Muppet Proof, prevents going to high idle out of gear, manufacturers have to assume some nutty owner will try it on stone cold engine.

Electronically controlled engines have a far more tightly controlled governor 'droop' some models close to Isochronous. Enables manufacturer to set engines up in such a way that they can optimise performance, far closer to engine 'critical' speeds than any mechanical motor, but at the same time preventing occasional excursion into 'critical' zone.

Visulise.........We used to have throttlemen on power boats, today we can have power boat driver who is (complete airhead), pulling WOT, max tight wire 95% engine load becomes airborne instantly releasing prop from load. In the blink of an eye ECU has dumped rail pressure and cut back fuel.........Vessel hits the water and props calling for 95% load again which is delivered in an INSTANT. Driver sees slight flick of tacho over perhaps 50 rpm range and never gives it a second thought. Engine is never wanders close to 'critical'. Guys who put this control software together are real stars in my book.

Engine management firmware is extremely sophisticated and does take away direct control of the engine form the operator but the guys who 'put this control software together' were doing it to reduce warranty claims.

Motor manufacturers use the same algorithms (or did until VOSA stepped in belatedly) to stop your engine or switch it into limp mode or limited operating strategy as its known, to protect the engine or its components* just when you least want or expect it. Concerns over the occupants safety at such times takes a back seat to reducing warranty claims.

Despite all the technology and sophisicated firmware, engines are less reliable than ever, because in my view, manufacturers skimp on build quality and rely on the ecu to detect and prevent failures...

It didn't stop my Citroen DS3 1.6 petrol turbo from needing a new engine after only 10k miles... I wonder how long the new one will last.

 

[essexboy]

If this is common practice, how do the do "Free acceleration" smoke assesment part of an MOT test ?