volvo 4.3 pre ignition

[johnnybay]

hi
i haver a rinker 192 with a volvo 4.3 gl 2005 model,now and again when i switch it off it seems to have a little pre ignition for a couple of seconds just sort of judders.

doe any one know what could be causing this and if it would damage the engine if it was just left like this.

many thanks johnny

 

[Haut Medoc]

Re: volvo 4.3 pre ignition

I'm not a Volvo guy, but what you are describing is called dieseling & is usually associated with fuel mixture, high idle or timing......
When was your last full tune up?.....
You need to corrrect the symptom as it can possibly lead to water ingestion into the cylinders.....
I'd look for Don S input for your particular engine......​

 

[Bondo]

Re: volvo 4.3 pre ignition

and if it would damage the engine if it was just left like this.

Ayuh,......

If you Don't Fix it,..... You're headed for a Junk Motor.......

When a motor diesels, usually it's last shutter is when it turns Backwards,+ Sucks water into the cylinders....
Hydrolock is the begining of the End of the motor.....

 

[johnnybay]

Re: volvo 4.3 pre ignition

thanks
for th help ,the boat has just had a full service last week,the mechanic
said it did not happen for him ,so he was not aware of it ,so he has suggested i try it out a couple of times to see if it is getting any worse , and then bring it back in .

 

[Haut Medoc]

Re: volvo 4.3 pre ignition

One thing you might try is letting the engine idle for a few minutes to cool down, this can help on some engines....
Is this a carbed or efi engine.....​

 

[johnnybay]

Re: volvo 4.3 pre ignition

thanks

now you mention it ,it does not seem to do it when i iam idling,i imported the
boat from the florida to uk over here ,do you think the octane difference could be doing it ,it still had fuel from the us in the tank ,and i put in some mixed in some from uk?

many thanks
johnny

 

[Silvertip]

Re: volvo 4.3 pre ignition

American engines are designed to run on 87 octane. If the octane rating is less than that you've found the problem. Timing would need to be retarded a bit to compensate. Otherwise, idle speed too high and engine bay heat can cause the problem. Try running with the engine bay open and see if the problem occurs. Also let the engine idle for minute or so before shutting down. Good practice even if dieseling is not an issue.

 

[johnnybay]

Re: volvo 4.3 pre ignition

hi
the octane rating over in uk is about 95 so that might not be the problem.