1984 Volvo Runs Rich!

[bruceb58]

Re: 1984 Volvo Runs Rich!

Then you have an AQ140.

 

[zvolv]

Re: 1984 Volvo Runs Rich!

AQ140! Fanstastic! Thanks! Now....to get the AQ140 to stop fouling plugs! What is the displacement of the 140?

My buddies just paid a LOT of $$ for the boat so I think I am gonna make them buy the proper Solex for the engine. I am no good at carbs so I would rather have the right one on there than tooling around with a non OEM carb.

This whole thing is funny to me because I have basically the same redblock in my 1991 Volvo 940 Turbo. 2.3L. I have been working on them for years! I just am much better at fuel injectors and turbos than I am at carbs and points!

 

[bruceb58]

Re: 1984 Volvo Runs Rich!

I may be wrong but i thought that the AQ140A engines also had 2 carbs on them.

 

[zvolv]

Re: 1984 Volvo Runs Rich!

It really am not too worried WHICH engine it is. I just want to focus on why the plugs are fouling out.

It looked like plug 2 was covered in oil. All three other plugs were fouled black. I hope its not in internal oil leak. I doubt it. If so, its half off day at the junkyard next week and the boat will get a $60 used block in it! Kidding...

So can a weak or out of tune ignition cause black fouled plugs or can it only be the carb?

 

[Maclin]

Re: 1984 Volvo Runs Rich!

From the scenario you describe, that it runs ok with new spark plugs for a while then starts missing out due to fouled plugs then it is more likely the carburetor. Improper dwell or timing could be a contributor, and it may need a good electrical tuneup as well but for them to be ok for that long it is probably fuel related. A weak ignition would have other symptoms before that 30 minute mark in my opinion.

 

[Don S]

Re: 1984 Volvo Runs Rich!

AQ140! Fanstastic! Thanks!

Don't get all excited, a 125 and 140 are close to the same thing, but I really don't ever remember seeing a 140 in any Bayliners. Determine what you actually have, not what someone on a forum THINKS it might be.

 

[Maclin]

Re: 1984 Volvo Runs Rich!

I think the AQ140 has a side draft carb.

 

[zvolv]

Re: 1984 Volvo Runs Rich!

I was just looking at a Haynes manual for my automobile Volvo and the plugs kinda fit the picture of Oil Deposits. "Oil is leaking past worn valve guides or piston rings into the combustion chamber. Causes hard starting, misfiring, and hesitation."

The number 2 fouled plug had what looks like oil on it. It never evaporated and the paper towel I had them on got kinda oily lookin. And there was smoke coming out the prop during flushing that could have been oil smoke. I also have heard that excessive rich conditions can cause the oil to wash off the side of the cylinder walls.

And the previous owner provided an invoice from Nov 07 complaining of excessive smoke. The headgasket was changed.

 

[Maclin]

Re: 1984 Volvo Runs Rich!

I hope this is relevant...

I was on Doug Russel site looking up stuff for my AQ271 and thought I would look all the 4 cylinder ones up, here is what I can gather from the parts list drawings from that site, looks like all the 4 cylinder offerings are dual carb, either side draft or downdraft.....:

AQ120B dual side draft

AQ125B dual downdraft

AQ130A dual side draft

AQ131A dual downdraft

AQ140A dual sidedraft

AQ145B dual downdraft


Here is a link to the Volvo choices, you can see the configurations for each by clicking the one you want to look up, then click the ALL link, then click the Fuel System link to see the intake configuration and the Carburetor link to see the carb explosion

http://www.dougrussell.com/partscatalog/volvo_omc/index.cfm?fuseaction=group&type=volvo&group=

 

[Don S]

Re: 1984 Volvo Runs Rich!

Looking at a bunch of parts breakdowns isn't going to help. I know how Volvo does it. They use a picture that is close, not exact.
All he has to do is get the number off the engine. No guessing after that.

 

[Maclin]

Re: 1984 Volvo Runs Rich!

Don S, all apologies to you that are due, I did not mean to get in your way.

In any event, a spark plug oil-fouling that fast is extreme and the engine needs work, a carb re-do or replacement won't help that one cylinder.

 

[zvolv]

Re: 1984 Volvo Runs Rich!

Looking at a bunch of parts breakdowns isn't going to help. I know how Volvo does it. They use a picture that is close, not exact.
All he has to do is get the number off the engine. No guessing after that.

Agreed. I have been in the Volvo community for about 10 years and their exploded diagrams dont mean crap.

Now I am all confused. Here is a link to the ebay listing where i got the pics from: http://cgi.ebay.com/ebaymotors/VOLV...003QQitemZ130209545651QQrdZ1QQsspagenameZWDVW

Now how the hell do I find out if its oil fouling? I have my compression guage sitting right next to my car keys right now ready to come with me next time. I guess a leakdown test would help. I dont know how to do that though.

If it needs an engine its getting a B230FT turbo engine and EFI to go with it. Just kidding, kind of, I dont think the car engine has all the proper holes drilled out for all the mounts and accesories. I'll just slap in a marine headgasket and run about 50 wires and call it a day.

 

[Don S]

Re: 1984 Volvo Runs Rich!

Now I am all confused. Here is a link to the ebay listing where i got the pics from:

Obviously the seller doesn't have a clue.

I guess a leakdown test would help.

Along with your compression test, absolutely.
http://vmaxoutlaw.com/tech/leakdown_tester.htm

If it needs an engine its getting a B230FT turbo engine and EFI to go with it. Just kidding, kind of, I dont think the car engine has all the proper holes drilled out for all the mounts and accesories.

And along way from being setup for marine use which is completely different from automotive.

 

[Maclin]

Re: 1984 Volvo Runs Rich!

I think your description of the #2 plug after the second run describes oil-fouling....:

"The number 2 fouled plug had what looks like oil on it. It never evaporated and the paper towel I had them on got kinda oily lookin. And there was smoke coming out the prop during flushing that could have been oil smoke."


It would definitely be smoking a lot if it oil-fouls that fast.

The 2 main culprits for oil-fouling to the extreme you described:

• Worn or broken piston rings
• Valve seals

Compression test should show noticeably low compression on #2 if it is rings.

 

[zvolv]

Re: 1984 Volvo Runs Rich!

Thanks for all your help today Don.

I appreciate all the advice from you guys. This is what forums are for, discussion. I love it! I dont expect somebody 4000 or more miles away to fix the problem over the internet. Just throw some ideas out there and leave it up to me.

Anyways...I posted this on a Volvo forum and one member asked me to let the plugs sit in the air for a while and see if the wetness evaporates. Well, 2 days later the OILY wetness is still on plug 2. No evaporation. I am starting to get worried.

But why are all 4 plugs black? Am I running rich and getting oil on me plugs. Related?

And I know it is blasphemy to run car parts in marine apps. Ask me what happened when I ran a $20 junkyard Chevy Astrovan oil pan in my $2000 rebuilt Mercruiser 4.3L Rusted through and cost me an engine rebuild.

 

[zvolv]

Re: 1984 Volvo Runs Rich!

I think your description of the #2 plug after the second run describes oil-fouling....:


It would definitely be smoking a lot if it oil-fouls that fast.

The 2 main culprits for oil-fouling to the extreme you described:

• Worn or broken piston rings
• Valve seals

Compression test should show noticeably low compression on #2 if it is rings.

OH NOO! Maybe you're right. It very well could be. Good thing its not my boat. I kinda wonder why the seller got rid of it after putting $2500 into it less than 6 months ago...I just feel sorry for my buddies who were dumb enough to pay $8000 for a boat and never put it in the water. The seller isnt returning phonecalls either.

 

[Maclin]

Re: 1984 Volvo Runs Rich!

I believe you have both things going on. The carb is rich, like WAY rich, and the #2 cylinder has a problem with sealing as well, more than the other cylinders. The #2 will probably be noticeably lower psi reading in the compression test.

 

[Maclin]

Re: 1984 Volvo Runs Rich!

Wow, I just read your last post, we posted at the same time...that is a bad deal for them.

Oh, one thing I have noticed with some well-worn automotive engines I have dealt with, if the timing chain is well worn as well they will foul plugs faster than you would think. I put new timing sets on a couple of them and they were able to run much better and longer between spark plug foulings, not really sure why.

Their engine probably needs a refurb, really sad. That certainly was a lot of money to pay for a boat that does not run any longer than that at a time.

 

[mcleaves]

Re: 1984 Volvo Runs Rich!

It really am not too worried WHICH engine it is. I just want to focus on why the plugs are fouling out.

It looked like plug 2 was covered in oil. All three other plugs were fouled black. I hope its not in internal oil leak. I doubt it. If so, its half off day at the junkyard next week and the boat will get a $60 used block in it! Kidding...

So can a weak or out of tune ignition cause black fouled plugs or can it only be the carb?

It matters if someone replaced a factory dual carb setup with a single. Since the carb setup is suspect it would be good to know what you have.

The Volvo 4 OHC's are all basically the same. Volvo essentially created the line by varying the engines with bore and single vs dual carbs or both. So all the intake/carb parts fit and are easily swapped, but can cause problems if they aren't the right ones.

For instance, I upgraded my single carb AQ125A to a dual carb from an AQ 140A or 145A (I can't recall - some were side Solex side draft's). It was a bolt-on solution.

M

 

[zvolv]

Re: 1984 Volvo Runs Rich!

The cam belt is timed correctly. I lined up the marks and confirmed piston 1 was at TDC thru the spark plug hole.

Mcleaves, thanks for the carb info. I believe the manifold is correct for the engine. The single downdraft carb setup. It sounds like I have the AQ125 engine.

Damn, and I cant run a turbo because there is no such thing as a marine turbo manifold for the engine. Oh well. It's half off day next week at the yard and a short block is $60. It would be a 2.3L auto engine though. I think the AQ125 engine is a 2.5L though...

I will do a compression test and see what I can find out. Under the engine cover there are numbers written, 150, 130, 150, 150. I THINK. I am not sure on the order of the numbers but I specifically remember seing 150 written a few times. The ink looks pretty fresh. Not that this means anything. I will put the guage on there and see what happens.

Here is a pic from my favorite Volvo auto engine I have built:



And the old engine:



The Volvo car nuts drool over the AQ171 engine because its is a DOHC 2.5L engine. Our cars come with a 2.3L SOHC