Calling all 8.1 Gurus (running rich)

SeadawgVB

SeadawgVB

Active Member
Jul 8, 2013
411
Tidewater Virginia
Boat Info
2004 480DB
Engines
QSM11
Hi guys! I got two of these 8.1s in my 360DA. Port engine is running rich. So rich that I am concerned about oil dilution (changed oil in both motors ~4 hours back on the engine clock). Actually I can see a few small droplets of rainbow producing petroleum product coming out with the exhaust / cooling water when at idle.

I've searched through this site and read the info about plugs / wires / injectors and obviously suspect one (or more) of those to be the culprit.

So I have a couple of questions that some of you may have run into and most likely resolved.

Since these motors seem to eat the recommended plugs (Delco AC 41-983, Mercury Bulletin 2006-03) like potato chips, what are you folks running as an alternative, Champion, NGKs?

What order would you tackle chasing the symptoms (I'm not getting the rattle from the flex plate / transmission)? Plugs, then wires, then injectors? I do have the Volvo Crusader wires on order as of yesterday.

So is there a way to isolate an injector problem (Since it seems to be a "richness" issue and not an obvious "miss" issue, my money is on the injectors.) short of the Rinda system or yank 'em all out and send them off?

P.S. I have not yet run the engines at night with the lights out, down in the engine room, but the thought has occurred to me.

P.P.S. I have considered picking up one of those Rinda tech or Diacom systems since I do most of the work down below.
 
scoflaw said:
Check your fuel pressure. If it's high you probable have the paint chip problem associated with the CF3
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Thank you, but I'm able to be thankful I have the cool fuel II on this year 8.1. When I first read about those issues I made a bee line to my engine room to check! What a nightmare!
 
So you checked the pressure ? The pressure regulator on that system can fail also, and I believe there is a small filter there as well.
 
Seadawg - one morning after starting mine, my wife smelled raw fuel - i went to the port side and it was burning my eyes - it was idling so rich. Turned out to be the Delcos! Plug changed fixed it for me...glad you have CF2 - I had that as well - trouble free.
 
Rut Row, Shaggy.....


41656736865_89882f6b5d_z.jpg
 
KevinC said:
Are we missing something here ?? Was that even attached ??

-Kevin
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Yes, there is something missing. It is no longer attached to the plug, it is now currently attached to the cylinder head. This is how a simple tune up can go south in a real hurry....

The above spark plug was in port engine, cylinder #6. Using only a ratchet handle, it broke apart leaving the lower half of the shell behind. It is with great trepidation that I take the next step......
 
Dave, don't turn the engine until you are 100% sure there is no spark plug pieces inside the cylinder. There was a similar problem with early Ford Tritons 5.4 V-8. Some spark plugs are made of two peaces together. Carbon build up around the plug. When you try to unscrew they split. Most of the time the other part drops inside. You have to remove the head to clean the cylinder. New designed plugs are one solid pieces. But some mechanics still decarbonize the engine before changing plugs. If you google it you'll find a lot of information about this problem on Ford engines.
 
SeadawgVB said:
Yes, there is something missing. It is no longer attached to the plug, it is now currently attached to the cylinder head. This is how a simple tune up can go south in a real hurry....

The above spark plug was in port engine, cylinder #6. Using only a ratchet handle, it broke apart leaving the lower half of the shell behind. It is with great trepidation that I take the next step......
Click to expand...

Maybe a very large screw extractor bit will bite into the threaded collar.

-Kevin
 
A trick the jet ski mechanics use is to spray down with penetrating oil, take a torx bit slightly larger than the opening where the insulator was and drive it in the opening and then back it out with a rachet. The extractors specifically for removing plugs in this situation are very hard (read brittle) and if you break one of those off there is no going back, head needs to be removed.
 
That looks rusty. Might be water in that cylinder. #6 is under the elbow. Are there any signs of water outside the joints btwn riser and elbow or riser and manifold.
 
Follow up. There was no water in the cylinder, this started out as a simple tune up..... There had been some raw water weeping out of the exhaust manifold (Less than a teaspoon over a long weekend trip.), but enough to cause corrosion on #6 plug.

I was able to get two types of extractors in the plug hole, a Snap On bolt extractor and a German made easy out. With my 3/8 inch electric impact wrench, no joy. Broke out the big gun. 1/2 inch drive air impact wrench that I use to pull lug nuts of my cars and trucks and can whip them off like no tomorrow. Anyhow, all it did was to sing the bit into the spark plug remainder even deeper. After hammering the easy out for over ten minutes without breaking it, that piece is completely seized up in that cylinder head.
Time to pull the head and hopefully don't break any head bolts...
 
Wow. Sorry to hear that. There is an old rule of thumb...if water is leaking on the outside you have to assume it's leaking inside too. I sure hope not but you'll be able to see what it looks like in there once the head is off. Good luck!
 
That is a first for me. I have seen thousands of plugs missing parts but never one that broke off that way. Are those the original plugs and how did the other plugs look? I'm curious if the original rich issue is on this plug or somewhere else.

I feel your pain on this. Tearing down an engine at the beginning of the boating season for a spark plug is heartbreaking. If the base of the plug is seized in the head....it probably is best to have a machine shop handle it or get a new head.
 
You may have already started pulling the head, but here’s a suggestion:

Can you find a left hand dill bit slightly smaller than the threads on the plug?

Maybe a few days of spraying it with penetrating oil (Kroil is good stuff) and drilling it out, it may break free. The heat from drilling and the resulting thin plug material remaining could possibly be enough to break down the rust on the threads.

Set the motor so the #6 intake valve is open and hook up a low pressure high/volume Fan to the throttle body.
This will blow any debris and metal shavings out of the cylinder as you drill it out.
 
Espos4 said:
Set the motor so the #6 intake valve is open and hook up a low pressure high/volume Fan to the throttle body.
This will blow any debris and metal shavings out of the cylinder as you drill it out.
Click to expand...

the exhaust of a wet/dry vac is a good source of high volume/low pressure air flow......I used this to blow water out of my engine block and exhaust components when I winterized a previous boat....

cliff
 
I would pull the head. The risk is far too great getting a single shaving that scores the cylinder wall and takes a $2k problem and turns it into a $20k problem. Right now he has two days of work and $1,200 for a new head. If the machine shop can fix it for a $200, he is ahead of the game. The manifold leak is the other issue to resolve. Then we can get back to the original issue of what caused the engine to run rich.

I would take the time to look closely at the injectors since he has to pull the intake manifold. That said, the spark plugs would definitely show a "rich" issue and point him to the injector to look at.
 
+1
PlayDate said:
I would pull the head. The risk is far too great getting a single shaving that scores the cylinder wall and takes a $2k problem and turns it into a $20k problem. .
Click to expand...
+1 I don't know if I would not risk it turning into a $20K job hoping a short cut worked either.

-Kevin
 
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