Volvo Penta 2003 Cold Start fuel enrich schematics

[vtomanov]

Does someone have a schematics of the VP 2003 cold start enrichment system (cold start mechanism located in the control box on the right hand side of the engine which can increasing the amount of fuel supplied by the pumps and normally controlled by the governor
) ?


e.g. technical drawings and descriptions how it should work and what can be adjusted ?

/ there are plenty of simple/brief descriptions but nothing in details that I can find/

my enrichment system on my VP 2003 seems to not work properly and I want to make it work hopefully with adjustments from outside , but if needed I will be happy to open it , but will be good to have a detailed schematics before that if possible ?

[sestina]

Are you employing the correct procedure?

Full throttle
Pull out and return stop cable
Throttle to half setting
Crank engine

[vtomanov]

Originally Posted by sestina

Are you employing the correct procedure?

Full throttle
Pull out and return stop cable
Throttle to half setting
Crank engine

Yes - exactly

( just the throttle to 3/4 not half - experimented with 1/2, 4/4 ad 3/4 all the same also )

[sestina]

Is your starter motor turning briskly enough? Are you losing compression?

I'd look into the simple stuff first!

[vtomanov]

Originally Posted by sestina

Is your starter motor turning briskly enough? Are you losing compression?

I'd look into the simple stuff first!

all good with starer and battery

[Pete7]

There is a spring in there which if it breaks stops the cold start procedure from working which is why he is asking and I am following because I might have the same problem.

Pete

[vtomanov]

Originally Posted by Pete7

There is a spring in there which if it breaks stops the cold start procedure from working which is why he is asking and I am following because I might have the same problem.

Pete

btw: the box is on the right side towards the front of the engine and mine also has part of the springs outside of the box ....

I desperately need a schematics before venture to open the box - I found a very generic schematics in the overhaul manual , but is not exact just generic one ..

[Paul L]

I always found with that engine that the exploded view in the parts manual was the best info available. I no longer have the parts manual or I'd scan the page for you.

[DougR]

As far as I know, there was never a schematic produced which dealt with the cold start mechanism on the 2000 series engines. The only thing you can do is check the parts book. Because the throttle and stop lever shafts are supported by the housing cover, it is difficult it see what is actually happening in there without cutting a large hole in the cover....( and that has been done before).

Basically the position of the fuel rack or control rod is controlled by the governor linkage and spring pressure applied by the throttle cable. At full throttle the linkage comes up against the max throttle stop, but when the the cold start is engaged, the stop is moved aside and that allows the linkage to move further than normal. This allows more fuel than normal to be injected, and if I recall correctly it also retards the injection timing so that injection occurs closer to TDC.

You can tell if your cold start mechanism is working by trying the following:
--ENGINE OFF--
Remove the 30 mm hex head plug on the rear surface of the block just to the rear of the last injection pump. Take care not to loose the washer under the plug. When this plug is removed you will see the aft end of the injection pump rack/control rod. With the throttle at idle, activate the stop lever, and the end of the rack will move aft and protrude about 4 mm past the surface of the block. Releasing the stop lever will allow the rack to move back into the block and it should reside about 4 or 5 mm ahead of the block surface. Now, put the throttle at its maximum RPM position and hold it there and then pull the stop lever all the way out and then push it back in again. When you do this stop lever movement, the fuel rack should move forward from its normal position until it is about 10 -12 mm ahead of the block surface. This is the cold start position.

If you get movements similar to these, your cold start is functioning correctly. You might find it easier to disconnect the throttle and stop cables from their attachment points on the engine in order to make it easier for one person to manipulate things and get full travel of the levers.

If you need a PDF of the parts book page, send me a PM and I will send it to you.

DougR

[vtomanov]

Originally Posted by DougR

As far as I know, there was never a schematic produced which dealt with the cold start mechanism on the 2000 series engines. The only thing you can do is check the parts book. Because the throttle and stop lever shafts are supported by the housing cover, it is difficult it see what is actually happening in there without cutting a large hole in the cover....( and that has been done before).

Basically the position of the fuel rack or control rod is controlled by the governor linkage and spring pressure applied by the throttle cable. At full throttle the linkage comes up against the max throttle stop, but when the the cold start is engaged, the stop is moved aside and that allows the linkage to move further than normal. This allows more fuel than normal to be injected, and if I recall correctly it also retards the injection timing so that injection occurs closer to TDC.

You can tell if your cold start mechanism is working by trying the following:
--ENGINE OFF--
Remove the 30 mm hex head plug on the rear surface of the block just to the rear of the last injection pump. Take care not to loose the washer under the plug. When this plug is removed you will see the aft end of the injection pump rack/control rod. With the throttle at idle, activate the stop lever, and the end of the rack will move aft and protrude about 4 mm past the surface of the block. Releasing the stop lever will allow the rack to move back into the block and it should reside about 4 or 5 mm ahead of the block surface. Now, put the throttle at its maximum RPM position and hold it there and then pull the stop lever all the way out and then push it back in again. When you do this stop lever movement, the fuel rack should move forward from its normal position until it is about 10 -12 mm ahead of the block surface. This is the cold start position.

If you get movements similar to these, your cold start is functioning correctly. You might find it easier to disconnect the throttle and stop cables from their attachment points on the engine in order to make it easier for one person to manipulate things and get full travel of the levers.

If you need a PDF of the parts book page, send me a PM and I will send it to you.

DougR

Hi DougR,

Done the test but not sure about the result to be honest:

1. if I pull the stop lever the control rod move aft

2. When I do the full procedure the result is :

- put throttle at max forward - the rod moves forward and stay there
- pull the stop lever - the rod move aft
- return the stop lever - the rod return to its previous position ( same as - before pulling the stop lever) - e.g. no difference if I have pulled and return the stop lever or not

does this mean that my cold start is not working ?

[DougR]

It sounds like the mechanism is not allowing the fuel rack to move to the cold start position. The fuel rack must move further forward than the normal full throttle position for the cold start to function.

DougR

[vtomanov]

Originally Posted by DougR

It sounds like the mechanism is not allowing the fuel rack to move to the cold start position. The fuel rack must move further forward than the normal full throttle position for the cold start to function.

DougR

btw: if the throttle is left on idle and when the stop lever is pulled up at the end a "click" can be heard well, but if the throttle is full forward there is no click sound to be heard...

I also opened the control box cover about 1/2 inch and all is visible but still trying to understend what pushes what

btw: if i push a little arm in the upper lefr corner with finger and leave the throttle on idle the engine starts in half turn from cold....

from the parts schematics is little bit dificult to understed the mechanics of movements inside - I'm still trying ... there is also a basic schematics of the box in the volvo penta serries 2000 service manual in the description how to dismounts the parts...

[vtomanov]

After long time of mingling about and talks from engineers to measure compression, injectors, filters, air in pipes, bad diesel and tons of suggestions for extremely expensive things to fix that are working well now is clear that the cold start procedure is the issue - opening the cap switching it on manually closing the cap and start the engine is working like charm from half a turn starts ...

the issue now is why the latch is not moved by pulling the stop cord... and find the actual problem and fix it..

[vtomanov]

Finally !

after a 4 try and give up over the last months... two days ago after 5_+ hours of adjusting, turning some metal parts, open, close, try, again open, close try endless times all is working as it should...

I have no idea why the hell volvo have designed so precise mechanics for a boat engine which should just work stable and forever

the whole thing is clever piece of engineering, but who need it as with simply adding one more lever to deal with cold start enrichment will sole all the issues and will be rock solid...

[Pete7]

What was the final solution? looks like I am going to print off this thread and take it down to the boat to see what is going on as I am sure I have the same problem.

Pete