Volvo pentas TamD. Wont start in neutral/idle

[mossym]

Hi all. Probably something very simple, but we have a birchwood ts37 with twin volvo pentas. Had some overheating issues recently, impeller gone, that's been addressed now, but now we cannot get the engine to start if it's in neutral it turns over, but wont catch. Almost sounds like it's starved of fuel.

If we give it some revs it starts immediately, and runs fine, until you put it back in neutral and it dies immediately

I didn't think it was supposed to start if it wasn't in neutral,but anyway any ideas what the issue could be? Thanks!!

 

[Bobc]

What bits ha e you removed or tampered with? Almost certain to be to do with one of those.

Air in fuel line?
Injection pump timing?
Glow plugs not working?

 

[Boater Sam]

Have you lost compression on a cylinder? A compression test will prove either way.

 

[PaulRainbow]

Hi all. Probably something very simple, but we have a birchwood ts37 with twin volvo pentas. Had some overheating issues recently, impeller gone, that's been addressed now, but now we cannot get the engine to start if it's in neutral it turns over, but wont catch. Almost sounds like it's starved of fuel.

If we give it some revs it starts immediately, and runs fine, until you put it back in neutral and it dies immediately

I didn't think it was supposed to start if it wasn't in neutral,but anyway any ideas what the issue could be? Thanks!!

Very confusing post.

Can you explain clearly what's happening, it's not clear regarding "neutral", is that out of gear or just with the lever at the idle position.

Also, is it both engines, or just one ?

 

[VicS]

Hi all. Probably something very simple, but we have a birchwood ts37 with twin volvo pentas. Had some overheating issues recently, impeller gone, that's been addressed now, but now we cannot get the engine to start if it's in neutral it turns over, but wont catch. Almost sounds like it's starved of fuel.

If we give it some revs it starts immediately, and runs fine, until you put it back in neutral and it dies immediately

I didn't think it was supposed to start if it wasn't in neutral,but anyway any ideas what the issue could be? Thanks!!

You dont say exactly what engine , TAMD40 ????
As PR says very confusing post re the meanings of idle and neutral.

Are you following the start procedure in the owners manual? It seems you may no be doing so

ITYWF that you should start the engines at about 1/3 throttle with the throttle disengaged from the drive. So in "neutral" but with the throttle position above idle speed.
Are you allowing the specified time for preheating ? (30 secs ?? ) Are the glow plugs working ?

Most worrying is that when you do start the engine it dies when the throttle is returned to idle . What is the rpm at idle. ? Is it the speed specified in the owners manual ?

Maybe some engine damage caused by overheating. As suggested, a compression might be advisable.

.

 

[mossym]

Sorry, let me try to clear the confusion.

have had the boat for several years, starting the engines was always with the throttle in the neutral position, drive engaged.

Engines are TAMD41
admittedly not me doing the work, co-own the both my dad and hes doing the work as he knows a lot more about engines than i do, but i have an account here so posted.

after the overheating he removed the raw water pump,, replaced bearing, seals and the impeller.

now if try to start with the throttle in the neutral position but wiith the drive engaged it won't start, it turns over but won't catch.

if we disengage the drive(pull out the throttle handle) and give it some throttle it starts straight away and runs no problem. until you pull it back to the neutral position. when it dies immediately, so can't tell what is idling at.

its jsut one engine, the one that overheated, other one is fine.

regarding the manual, its an older boat so not sure where the manuals are, startup procedure was picked up from the previous owner

 

[VicS]

Sorry, let me try to clear the confusion.

have had the boat for several years, starting the engines was always with the throttle in the neutral position, drive engaged.

Engines are TAMD41
admittedly not me doing the work, co-own the both my dad and hes doing the work as he knows a lot more about engines than i do, but i have an account here so posted.

OK .
I agree the TAMD41 should be started with the control levers in the idle/neutral position..

If nothing else was touched when the pump impeller was replaced, in particular the idle speed adjustment, it seems likely that some engine damage was caused by overheating unless the engine was shut down as soon as the alarm sounded.

See the troubleshooting guide in the owners manual

Consider bleeding the fuel system ( see the manual )
Have you tried running the engine at a fast idle for a few minutes , or won't it fast idle.

Probably a job for a professional who has the equipment to carry out a compression test although you can hire them.

BTW the owners manual can be downloaded from Manuals & Handbooks | Volvo Penta UK & Ireland (Type TAMD41 in the product designation box and pick the correct variant from the drop down list)
.

 

[Plum]

Sorry, let me try to clear the confusion.

have had the boat for several years, starting the engines was always with the throttle in the neutral position, drive engaged.

Engines are TAMD41
admittedly not me doing the work, co-own the both my dad and hes doing the work as he knows a lot more about engines than i do, but i have an account here so posted.

after the overheating he removed the raw water pump,, replaced bearing, seals and the impeller.

now if try to start with the throttle in the neutral position but wiith the drive engaged it won't start, it turns over but won't catch.

if we disengage the drive(pull out the throttle handle) and give it some throttle it starts straight away and runs no problem. until you pull it back to the neutral position. when it dies immediately, so can't tell what is idling at.

its jsut one engine, the one that overheated, other one is fine.

regarding the manual, its an older boat so not sure where the manuals are, startup procedure was picked up from the previous owner

" if try to start with the throttle in the neutral position but wiith the drive engaged it won't start, it turns over but won't catch." Some engine control levers have a built in isolator switch that prevents the engine starting with the drive engaged to stop owners starting with the drive engaged.

 

[PaulRainbow]

" if try to start with the throttle in the neutral position but wiith the drive engaged it won't start, it turns over but won't catch." Some engine control levers have a built in isolator switch that prevents the engine starting with the drive engaged to stop owners starting with the drive engaged.

Some do, but they usually stop the engine from turning over, the OP says his turns over.

 

[Bobc]

Oh dear.

Sorry, let me try to clear the confusion.

have had the boat for several years, starting the engines was always with the throttle in the neutral position, drive engaged.

Engines are TAMD41
admittedly not me doing the work, co-own the both my dad and hes doing the work as he knows a lot more about engines than i do, but i have an account here so posted.

after the overheating he removed the raw water pump,, replaced bearing, seals and the impeller.

now if try to start with the throttle in the neutral position but wiith the drive engaged it won't start, it turns over but won't catch.

if we disengage the drive(pull out the throttle handle) and give it some throttle it starts straight away and runs no problem. until you pull it back to the neutral position. when it dies immediately, so can't tell what is idling at.

its jsut one engine, the one that overheated, other one is fine.

regarding the manual, its an older boat so not sure where the manuals are, startup procedure was picked up from the previous owner

It's beginning to sound like you might have done something like blown the head gasket or warped the head by overheating it.

 

[westernman]

Sorry, let me try to clear the confusion.

have had the boat for several years, starting the engines was always with the throttle in the neutral position, drive engaged.

Engines are TAMD41
admittedly not me doing the work, co-own the both my dad and hes doing the work as he knows a lot more about engines than i do, but i have an account here so posted.

after the overheating he removed the raw water pump,, replaced bearing, seals and the impeller.

now if try to start with the throttle in the neutral position but wiith the drive engaged it won't start, it turns over but won't catch.

if we disengage the drive(pull out the throttle handle) and give it some throttle it starts straight away and runs no problem. until you pull it back to the neutral position. when it dies immediately, so can't tell what is idling at.

its jsut one engine, the one that overheated, other one is fine.

regarding the manual, its an older boat so not sure where the manuals are, startup procedure was picked up from the previous owner

Sounds like the idle adjustment is way off.
Should be an easy fix.

Is the throttle cable properly connected? I.e. there is not something somewhere it should pass through which it is not doing now?
Is it properly connected to the throttle lever (and not out of the slot/connecting thing)?
Ditto at the other end.

 

[mossym]

my thanks to all for taking the time to reply on the discussion here.
fortunately it turned out not to be any damage to the engine due to the overheating, and was down to the impeller replacement and a mix up when the new one was replaced(more down on the rubber seals around it than the impeller itself. thats been addressed, and the engine is now running again as expected. need to take it for a test run to make sure its 10% resolved, but the issues i described very badly above at least seem to be rectified.

thanks again

 

[VicS]

I do not see how anything about the pump impeller or any seals can affect the starting