Need 2008 VP 5.7 HELP!!!! PLEASE

[Lou C]

The water issue is curious you should be able to put your muffs on and see water come out of that water transfer hose as long as:
the muffs fit right (and some are too stiff to fit right, I had this problem with the dual inlet Tempo muffs I got a few years ago). I wound up switching to the Merc/Quicksilver ones that are made of softer rubber and fit better.
and, the water tube grommets inside the drive are in good shape.
The fact that the engine does not over heat suggests that the issue you are seeing is due to less that perfect fitting muffs. It runs at normal temp in the water, correct? 160-175?

next I’d be very curious to find out what if any specs are different from the original engine and what MM sold you...

lastly are you SURE there are no vacuum leaks around the intake manifold? Ever hear a hissing sound? The intake gaskets on Vortec engines can be problematic...

sorry I just have no experience with marine EFI engines, only familiar with old school carbs (Quadrajets and Holleys).

 

[Lou C]

PS
another thought,
can you hook up a vacuum gauge to the intake and see what it reads at idle and what happens when it starts surging?

 

[Lou C]

And...just thinking if the EFI system enriches the mixture for cold starts and cold running, but that switched off after it reaches a certain temp (lets say 160) so the mixture leans out as it should, if there is a vacuum leak that could possibly explain it...

 

[Regal1973]

Ok guys, thank you for all the responses! I THINK I HAVE IT FIGURED OUT!
So it was susggested here ( a big thanks to Alldodge!!) to reach out to Bob at Mefiburn.com so I called and left a message.

Well, Bob called me back today. First I'd like to say he is a great guy! Although he doesnt work with my computer, he took the time to make a few suggestions. As we went through many scenarios, he mentioned the adjustable throttle stop screw on the throttle body. I explained that I was told by the VP shop not to mess with the screw because it's set at factory and not designed to be adjusted. Bob said because it's a mechanical throttle body (not fuel injected throttle body), it has to be adjustable. He suggested I very slightly adjust the screw to cause the throttle body butterfly blade to open and see what happens.

Well the slotted screw was stuck like chuck. Even with break free oil it was a no go. I started the motor and for whatever the reason, I decided to press on the butterfly with Very Very Heavy thumb pressure, pushing the blade closed very hard...and bingo! Smooth idle!!!!! Since I couldn't get the throttle stop screw to adjust, I did the next best thing and I took some channel locks and ever so slightly bent the throttle arm to allow the butterfly blade to close completely. It was such a slight difference in blade angle, I couldn't even tell the blade was really moving when I pushed on it. I mean it hurt my thumbs pushing the blade closed to get it to idle smooth.
After I bent the arm, I let it run for 15-20 minutes, it went through several warm & cool phases and the idle never lopped up & down.
I will keep everyone posted on how it does out on the water this coming week. A Huge thumbs up to Bob at Mefiburn!!!!!!! & to everyone here who has offered their time and knowledge! I'm very grateful for all who offered suggestions. If this is the fix for the idle issue, it has been 1 1/2 years of asking, begging & demanding the VP shop who installed it to get it right.....which they never did, but thanks to all here, it might just be solved!!!

 

[muc]

EDIT; Hope that bending the throttle keeps working for you.

Engine serial number. I can usually get this with your hull number, drive or transom serial number.

170-175° on muffs or in the water with no load is too hot. You have a problem.

Right now your symptom is "hunting at idle", there are many things that can cause this. To correct this you should use the process of elimination. Find something wrong and correct it, then retest. It is likely more than one thing that's causing it.

When you inspected the thermostat housing, did you run a wire thru the bypass passage? It is a small passage (a little bigger than a coat hanger) that you can see one end of when looking into where the hose from the circulating pump (largest hose) connects.This would be the first thing I would check.

So you have found a possible problem (175°) now you need to determine, is it a problem? Could just be the gauge reads high? Maybe you could shoot it with a temp gun? Best would be to hook up a scan tool and see what the ECM thinks the temp is, That would also give you the chance to see what the intake air temp is, I think you have a TMAP sensor. Can't be sure without a serial number.

Stop trying to troubleshoot the aeration problem with muffs. Too many variables there for a boat owner. You can use the muffs to check your work after inspecting the bypass passage.

At this point it's possible --- but not likely --- there is an issue with the calibration in your ECM and the new motor. But it's still to early to know. Lets hope not, because it will be very difficult to resolve. Think about this. Volvo could have bought the same motor that Michigan Motorz sold you (probably at a better price) to sell you as a replacement engine and opted to offer a reman instead.

Sorry, but I can't answer your questions about why Michigan Motorz did this. I try to avoid aftermarket sellers because of problems like this. But we still don't know it's their fault.

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[Regal1973]

Okay guys, got the boat all ready to go out Sunday and give it a test run. Started the motor up today just to make sure that everything was good in good order, and it immediately started idling super rough.

Advanced the throttle a few times and when I'd pull it back to neutral it died on me. Eventually got it to run but it just didn't sound right. I looked out the back to find tons of black soot coming out the exhaust. I put a white bucket under exhaust discharge and man, its solid black!

I don't know if this is related to me slightly bending the throttle arm to get it to idle smooth as I described in my earlier message or if this is something that has just come on. My guess is that it's running super rich now but I don't understand why, seeing as I just slightly bent the throttle body arm. I bent it so slightly that it was literally the thickness I'm a larger feeler gauge.

What to do now????? Bent the arm completely back to how it was? Pull the spark plugs? What the heck.....I can't seem to win right now : (
If someone can suggest ideas, I'd appreciate it!

 

[Regal1973]

Pulled one plug and it is solid solid black. The plugs that I have are ACDelco mr43lts. The motor is a 2008 5.7 g i-g.
I seem to remember that when I had the motor shipped to the Volvo Penta shop, they said that the plugs that came with the motor from Michigan Motorz were incorrect and these are the plugs that the VP shop put in it before installing the motor. I wonder if these are the correct plugs? Even with my original idle issue, I've ran it off & on over the last year and never had this type of issue. I'm guessing it's related to me adjusting the throttle arm because this issue just came on but I'm not sure how bending it so so slightly caused this.

 

[Bondo]

Pulled one plug and it is solid solid black. The plugs that I have are ACDelco mr43lts.

Ayuh,..... Right plugs, but it's gettin' to much fuel,...... Black comes from to rich,....

 

[Regal1973]

Bondo, do you think me bending the throttle arm on the throttle body, realistically the thickness of a steak knife blade would cause this issue?
I bent it to allow the throttle plate to close all the way. I figured the IAC valve would make adjustments as needed.....

 

[Regal1973]

There is an adjustment screw to adjust the throttle plate but its frozen & wont budge. I bent the arm of throttle body in lieu of the ajustment screw to accomplish the same thing.

 

[alldodge]

Was not running rich but after bending arm you are, so try to bend it back

Plugs where not black but now they are, so as others, its to much fuel

I'm thinking its either IAC or Temp sensor, or combo of both

 

[Regal1973]

I bent the throttle arm back to basically where it was. Started it up and it still blowing out tons of black soot and haze. Guessing I will need to pull the plugs and replace now huh?
why would allowing the throttle plate to completely close cause this? The IAC still sucks air,,
so I'm completely confused.

 

[Regal1973]

AllDodge, yes I never had this rich issue before.
I thought I had figured out my original idle issue when I allowed the throttle plate to close completely by bending the throttle arm. Tomorrow was going to be my test run day and I thought I better give it a go in the driveway before I headed out in the morning. Good thing I did!
Now my plugs are all black and no local places have them in stock grrrrrrrrr!

 

[alldodge]

Throttle plate should never be completely closed (least what I found). My TB was bent on delivery so I broke the set screw loose, adjusted so it just barely touched, then locked it down and has work fine ever since.

There is nothing wrong with using black (carboned up) plugs. If the motor starts running better the black will disappear, and cleaning plugs with wire brush will do. Need to find out why its rich.

Go back to basics, has pressure changed? Is there a vacuum leak? Need to scan motor to see what the PCM is seeing

 

[Regal1973]

I found eight plugs at a local auto parts store so I'm going to run and pick them up now. Is there a way to reset the computer so that I hopefully dont ruin the new plugs?
trying to get this resolved this evening as tomorrow is my only day to take the boat out.

 

[Regal1973]

AllDodge. I'm going to run and pick up a set of plugs anyway just to have. Probably a good idea to have a set on hand anyways LOL. Nothing was done or changed since the other day when I made that throttle body adjustment. I went back over the top side of the motor that make sure that nothing was just connected, loose, or anything of the sort. The only thing I can contribute it to is adjusting that throttle body arm where the arm makes contact with the adjustable screw.
​​ Should I replace just one of the plugs with a brand new one, start the motor up and run it for a couple minutes then shut it down, pull the plug and see if it's also turning black now that I've set the throttle body arm back to where it was?

 

[alldodge]

Should I replace just one of the plugs with a brand new one, start the motor up and run it for a couple minutes then shut it down, pull the plug and see if it's also turning black now that I've set the throttle body arm back to where it was?

If your blowing black smoke, then no need to check plugs.
No need to use new plug, could just wire brush an old one and stick it back in for the test

 

[Regal1973]

Do you think the plugs will clean up on their own if I don't remove and wire brush them
and just run the motor now that I've got the throttle body arm adjusted back? They are super super black. Or should I just remove them, clean them the best I can and then reinstall ?

 

[Regal1973]

Wondering if the coil could have gone bad? If all the sudden it started having this issue and all the plugs are completely sooty, then maybe it's not putting out the spark needed to burn off the fuel? I dont know if all the plugs are sooty just yet, because I havent pulled them all out yet, but I'm guessing they are with the amount of solid black soot coming out the exhaust.

 

[Wave34]

I bent the throttle arm back to basically where it was. Started it up and it still blowing out tons of black soot and haze. Guessing I will need to pull the plugs and replace now huh?
why would allowing the throttle plate to completely close cause this? The IAC still sucks air,,
so I'm completely confused.

May be with the plate completely closed, the IAC cannot open enough, so, not enough air, and rich mixture...

I know you checked the data value with a scanner, but just for the heck of it, check for corrosion inside the sensor's connector, and on the ground terminal block terminals. Usually located on the transom behind the engine.