Volvo Penta 2.3L AQ131 runs better with timing advanced

[sctbirdguy]

I have been fighting an overheating problem and have given up, just going to run it until melt down. However, I noticed tonight that the boat runs way better with the timing advanced a bit. It’s starts easier both cold and hot, idles much smoother, comes out of the hole without hesitation, runs up to 4800 rpm like a champ (redline). I also do not detect any pinging at WOT.

I have replaced almost everything on the engine including the timing belt and tensioner. Also, I cleaned and lapped the valves while it was apart. I triple checked all three pulleys and timing belt and everything is aligned correctly.

The factory settings are 6 degrees btdc at 850 rpm and 36 degrees at 4000 rpm with 62 degrees of dwell + - 3 degrees.

My current set up is 13 degrees btdc at 850 rpm and about 42 degrees at 4000 rpm and 61 degrees of dwell. It has the stock points.

Does anyone see a problem with this? My dad tells me a story about a mechanic that tuned by ear and hecompletely changed his cars performance and gas mileage etc. and the mechanic said sometimes the stampings are off.

Looking for opinions.

Thanks.

 

[Scott Danforth]

you would not hear pining

I would not run that far advanced

is your dwell set right?

 

[Bondo]

you would not hear pining

I would not run that far advanced

is your dwell set right?

Ayuh,..... Welcome Aboard,...... Sounds like a great way to hole a piston,.....

 

[sctbirdguy]

Ayuh,..... Welcome Aboard,...... Sounds like a great way to hole a piston,...

 

[sctbirdguy]

I know when I was messing with the distributor when I forgot my timing light I could definitely hear ping then I backed it off and it went away. I can hear my Buell ping on hot days. Plus you lose a ton of power.

The dwell is perfect at 61 degrees….which I think is high personally.

The thing has tractor style copper spark plugs. I have never seen a hole like that. Now I kinda want to see it happen….if it was a funny car I can see it but this 600 lbs turd with 110hp and 5:1 compression..I don’t know. Now I am interested for science! I am only out an engine that overheats!

 

[QBhoy]

Is your belt a tooth out ?
Do those engines not often tend to suffer cylinder head issues ? You think there is any chance you may be compensating for an issue, by means of timing advance ?

 

[kenny nunez]

If you turn the engine over eventually the marks on the belt will Aline with the marks on the respective sprockets. Quite often whenever I changed a belt when the tensioner was released the belt would jump 1 tooth. It is worth double checking .
The electronic ignition conversion kit for your engine is Sierra # 18-5292.

 

[sctbirdguy]

Not sure about the cylinder heads being a common problem. Mine was resurfaced just last week because it was a bit out of shape from a severe overheat from the person I bought it from. I am sure I am not off by a tooth. I triple checked. Only noticing because when I got the boat it was running the timing advanced as well so I put the timing back to factory but I was almost out of adjustment. I found this strange. Well when I reassembled the engine last week (replaced the timing belt and tensioner too) I didn’t adjust the timing because it ran when I took it apart. It wouldn’t even pop. Adjusted the timing and if fired right up. Now the adjuster has room both directions like it should, advanced as I have it now or stock. Still lots of adjustment. Long story short the intermediate shaft that spins the distributor must have been off by a tooth and was being compensated by more adjustment of the distributor now it’s not.

I don’t see what else I am missing. It’s possible something is being compensated for but I am at a loss.

The other odd thing is the in-laws have the exact same boat and I have it set to factory timing and it starts hard too like mine when I have the timing set to factory. This is also why I put the old fashioned factory recommended spark plugs in it. I laughed because the temp range for the factory plugs just showed a penquin with an arrow pointing down..

Is the timing and smoother running engine in response to our disastrous ethanol fuel that didn’t exist in 1992?

I don’t know. This has me stumped. Which I suppose is not too hard.

 

[sctbirdguy]

If you turn the engine over eventually the marks on the belt will Aline with the marks on the respective sprockets. Quite often whenever I changed a belt when the tensioner was released the belt would jump 1 tooth. It is worth double checking .
The electronic ignition conversion kit for your engine is Sierra # 18-5292.

I triple checked. I was responding while this post appeared and explained it below. I didn’t line up the marks on the belt because well rules are for others and not for me!

Thank you for the electronic ignition part number. I was looking to do that next year. Just trying to make sure the boat is reliable enough for the kids to take out while at the cabin.

 

[kenny nunez]

One other thing that helps with starting. Take a look at the solenoid and there should be a male spade on the outboard side. If you run a wire from it to the + or bat side of the coil it will provide 12 volts when the starter is engaged. Check it with a test light or a volt meter first to check it is working.
Genuine Volvo Ignition switches have the circuit but most boat manufactures use generic instrument panels which do not have the Volvo switch.

 

[sctbirdguy]

One other thing that helps with starting. Take a look at the solenoid and there should be a male spade on the outboard side. If you run a wire from it to the + or bat side of the coil it will provide 12 volts when the starter is engaged. Check it with a test light or a volt meter first to check it is working.
Genuine Volvo Ignition switches have the circuit but most boat manufactures use generic instrument panels which do not have the Volvo switch.

Good idea. I will check that. I did think this was a full 12v to the coil system all the time but that is from memory and that only gets worse each day!

 

[Scott06]

Good idea. I will check that. I did think this was a full 12v to the coil system all the time but that is from memory and that only gets worse each day!

Any pints system will go through a resistor to drop voltage to around 9 V to improve point life.

When you crank the voltage in the system is going to drop so the 9 bolts would go even lower creating a weak spark. So they wire a full 12 v to coil that is only powered during cranking, usually done off a starter lug as suggested.

A couple years ago I converted my 65 Pontiac to electronic ignition. Single biggest improvement was in starting. Fires right up vs points.