Volvo 8.1 nightmare

muc

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Test section, relay test, all relay's should run the fuel pump.

Boat tachs are usually off a bit. One of the reasons scan tools are so important.

In the water, in gear, run the idle speed test at the RPM that your having a problem with. Problem still there?
 

muc

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If my memory is correct. The spark plugs should have come pre-gapped at 0.060"
 

jgerardi

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Ok, so here is where i am at with this.
Keeping in mind i only have the EFI repair workbook from Volvo and the Seloc manual. The other manuals are en-route. I also have the ECC manual but it is for the 8.1 Gi-G. (i have the 8.1 Gi-H) . The EGC manual is on its way.
I replaced the wires and it had no effect.
I did a vacuum test as per the service manual and it holds steady at 17 inches. Now according the the manual, "A steady vacuum reading between 14 and 19in. Hg. (47-64 kPa)at idle indicates an engine in good mechanical condition". The vacuum remains pretty steady as i gradually increase the RPM. A hard acceleration drops the vacuum but it recovers in probably less than a second. The manual does talk about a decrease as rpm goes up, but it clearly states a steady increase. So ultimately i think my vacuum test is good.
I tested fuel pressure. My boat the pumps run for 5 seconds when you turn the key on. While they are running, the pressure runs up to about 50 but once they stop, the pressure stabilizes at about 40-41. I cant find the correct fuel pressures in the Volvo manual that i have at the moment, but the seloc manual says 36-44 for the 8.1 (50-60) for the others. The presure holds steady there with the engine and pumps off. According to seloc the pressure should not drop more than 2psi over 10 minutes. It is holding steady.
My compression test was good. 160 was the low and 175 was the high.
As for the DTC's. There were quite a few (attached but based on the amount of engine starts since, they all seemed to happen quite sometime ago. Im thinking they all may have been a result the hull flooding and slinging water all over the place. There was quite a bit of water in there and the engine was not running properly when it happened. When i shut the engine off it took about 20 minutes after pumping the water out to get it started again.
I cleared the engine codes and ran the boat at idle for a bit, then took it out and ran it up and down the intracoastal for about 2-2.5 hours at 700 - 2500 rpm. I checked again and no codes.
So long and short of this, i spent a lot of money on software and some other things and haven't really gotten anywhere. I learned a lot and that certainly has value. Hopefully when the books arrive i might get some more insight. Im going to quadruple test all of my connections again while im waiting on them.
If anyone has any input based on what i have so far, by all means, comment away.

JG
 

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muc

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I think 50psi is too high. Has the pump been replaced? There is a recall on some 8.1 replacement pumps for a bad regulator. Service Bulletin 23-3-134 ver. 2 covers them.
Fuel pressure is 40psi +/- 4psi. You should test with the engine running. Should be 36-44psi with vacuum line to regulator disconnected and drop 3-5psi when connected @ idle. Should also test at all RPMs and loads. Especially at the speed your having a problem.
I think the -G manual will work for you.
Agree that the codes probably don't mean anything, suggest you clear them and see if anything comes back.
 

jgerardi

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I re-did the fuel pressure test. For some reason all of the results were different. Since i dont have access to most of my tools (they are in NY) i borrowed the fuel pressure test kit from AutoZone. The 90 degree adapter i need to clear the throttle link was tough to get on and allow fuel to flow through it. The rubber inserts that seal it are a little deformed and they were hard to get a seal out of. I had to tighten it down quite a bit and I think that restricted the flow a bit. With all of that said.....
With the pumps on and engine off.....51psi
Pumps off, engine off.....45-46 psi
Engine at idle, vacuum line off of regulator....51psi
Engine at idle, vacuum line on . 46psi and not very stable. Appears to be jumping around between 45-48
Boat underway at every speed and load. In other words, accelerating, decelerating, on plane and maintaining speed. The pressure jumps around a bit 45-48. Not slow variations but the gauge is fluttering for lack of a better word.

Clearly the pressures are somewhat high. This fuel cell has the regulator that is on the cell itself, not the one on the fuel rail. I have no way of knowing if this is the original cell or not. I have most of the service records at home which i did look through when i got the boat but don't recall the fuel cell being replaced. I tried to find the recall/SB that was mentioned and couldn't find anything. Im going to get another gauge and double check those readings. If they are correct i'm assuming im looking at a new regulator. If it needs to be replaced, then it is what it is.

I know there have been issues with these fuel pumps, paint chips and alcohol additives to fuel. As i understand it there are two types of additives. Ethenol and Methenol. When i did the motor, i flushed the fuel rail and screened everything that i ran through it. There was no indication of any paint in the fuel rail. I also inspected the screen on the fuel rail with the same result. Point being that i dont think i have an issue with this.

If the fuel cell is original then it has upward of 800 hours on it. As i mentioned in an earlier post, the pump sounded quite loud and i was thinking the LP pump might not be working properly because of a corroded connector. I replaced the connector and the pump stopped making the noise. I can still hear the pump running but i have to get pretty close to hear it. I am assuming it is normal to get some sound from it.

So far, i have run the boat for about 4 hours at various different speeds, loads and RPMs and it still isnt throwing any code.

Thoughts?
 

alldodge

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Im going to get another gauge and double check those readings.

Would be a good move to verify from a rental gauge

Not seeing the fuel pressure giving a stumble spot even high
 

muc

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Would be a good move to verify from a rental gauge

Not seeing the fuel pressure giving a stumble spot even high

Agree to try another gauge, or try gauge you have on a different engine. The regulator is around $200, so it's best to be sure.
A little gauge flutter is fairly normal.

Might be time to do a recording.
Hook up the scan tool, start the engine, hit record and drive the boat for about 20 minutes. Bring the boat back to the dock and stop the recording.
Make sure you spend some time at the speed the issue is happening and get up to top speed for awhile.

You will have to ask a dealer for the service bulletin, I'm not allowed to post them.
 

jgerardi

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is there a test to check if the fuel injectors are firing the correct amount of fuel? Since the drop test shows that they are flowing fuel, im just curious on how to tell of they are flowing the correct amount.
Additionally, when i removed the engine, the coupler looked like the rubber had moved around inside the housing. I replaced it. When i removed the engine for the second time to replace the ring gear on the flywheel, i noticed that the new coupler had done the same thing.
When I put the outdrive on, i had a ***** of time aligning the engine. Eventually i got there. I was able to slide the tool in and out with not much effort. One handed was my bench mark and still, not a lot of effort.
I posted a picture of my old coupler on here and was told it looked fine. I am posting it again to get a second, third opinion. Im just wondering if this could be causing the issue. Im inclined to think that if the coupler was causing this it would get worse and increased speed/rpm.
Both of these pictures are the same coupler from different angles
 

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alldodge

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Injectors can be flow tested by sending to a "marine" injector service. While auto places can do it, most wonludn't normally test to 6000 rpm.

Your coupler looks good
 

muc

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Coupler looks ok, but it’s hard to tell with a picture.

There is a test listed in the manual, if I remember right it’s called injector balance test. Years ago I have done this test many times. Both Volvo and MerCruiser have requested this test as part of warranty diagnosis. I would never recommend this test to a paying customer. It’s a time consuming test that doesn’t provide quality results. Part of the problem is your looking for differences of 1/4 to 1/2 psi. Most gauges don’t have enough resolution to give conclusive results. It is usually more cost efficient to send the injectors out for flow testing and reconditioning. Beware who you pick for this service. I’ve had injectors come back in worse shape than when I sent them in. If you decide to do this (it is a commonly needed service) and would like a recommendation, send me a PM and I can give you the name of the company I use.

When you get the wiring diagram for your engine, use it to make sure the injectors are plugged into the right colors.
 

muc

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Missed the alignment part.
In school they teach us that the tool should slide in and out using only two fingers.
What some people miss when doing this job, you MUST check alignment at 12:00-3:00-6:00 and 9:00 o’clock.
I’ve had more than a few new couplers that had to be returned for this defect. Got so bad in the early 2000’s that we started using a dial indicator to check the coupler before installing the engine back in the boat.
If the coupler is just a little off, you can usually get them to re-center by setting the alignment so it is equally off all around and running for a month or two.
 

jgerardi

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Although i have been told the two finger rule, i did grease the coupler and tool up and since the inside of the coupler is pretty tight against the flywheel, with the grease in the splines that would cause a little bit of pressure and vacuum when sliding the tool in and out. Although i get the need for proper alignment, i'm also inclined to think that the whole design of the coupler is done to account for some very slight misalignment. Lets face it, although they recommend that the alignment be checked periodically, i doubt most people do it.
I have 3 more weeks here in Fla. Once i get home, i am going to pull the injectors and send them out. I will get the name of your guy by PM. If the injectors have ever been serviced, im sure it was many many hours ago so there is probably no harm in doing it.
Also, i went ahead and (dont cringe) bought a Delco 8.1 crankshaft sensor and dropped it in. Seems to have improved the condition considerably. Ill get the Volvo one. The delco was only 23.00 so i figured it was worth a shot. I realize the intrinsically safe parts should only be used, i didnt see the sensor as a concern. As soon as the engine warmed up, I could see the engine was idling more smoothly. Im wondering if this might be a combination of things.

Another question. I have to winterize my boat before i head back. Cant chance anything freezing up if i hit bad weather on the way or if it is below freezing in NY. I was taught to winterize the boat by pumping antifreeze through the motor until the thermostat opened up and that is how i have always done it with no problems. I read in the service manuals that all that is necessary is to level the motor, pull the drain plugs on the motor and manifolds, and take the hoses off the raw water pump and let everything drain fully. Do you feel this is adequate to winterize or do you suggest the antifreeze as well or in addition?
 

alldodge

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VP doesn't make the CPS, Delco, Delphi make them. IMO I wouldn't change it

Muc's injector guy is BUP (John) and is good, and even more so in his own mind. He is good at injector testing just and spends his time on OSO

https://www.boatunlimited.com/

As for winterization, if you drain all the water out, air doesn't freeze.
 

muc

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VP doesn't make the CPS, Delco, Delphi make them. IMO I wouldn't change it

Muc's injector guy is BUP (John) and is good, and even more so in his own mind. He is good at injector testing just and spends his time on OSO

https://www.boatunlimited.com/

As for winterization, if you drain all the water out, air doesn't freeze.

Yes, John is who I recommend. Very very knowledgeable about injectors, ECMs and 8.1s.

CPS at $28.00 for my personal boat, yup I might try that. As a Volvo dealer tech, that’s not allowed at the shop. If it’s working I would leave it in. You’re correct that some unusual problems have more than one thing going on.

Alignment, yes many people skip this maintenance. Until they have to pay for a coupler job. Like most maintenance. If it’s worth doing, it’s worth doing it correctly.

Winterization, there is more to lay up than just freezing. Volvo put out a service bulletin a few years ago changing their recommendation to use antifreeze for “long term lay up” to a requirement. If you will have the boat back in the water in one or two months, you could probably skip it. Having been in the boat business in Minnesota for over 30 years. I have seen the results of using the proper antifreeze for storage and I highly recommend it.
 

jgerardi

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I received that last shop manual i ordered. The EGC manual. Has considerably more information than the PDF version i had for the Gi-G, My boat has the Gi-H. In any event i have noticed there are many references to the DTC resetting. Is there a point where the DTC will no longer show up in stored DTCs other than when they are cleared? The manuals also make many references to the MIL which i do not have.
Another thing i noticed. The wiring diagram for the injectors shows that the common wire for the port side 1,3,5,7 cylinders should be pink and for the starboard side should be pink/white. Mine are opposite. Now i don't see that it could be physically possible to have the two sides reversed based on the routing and position of injector harness's main plug and where it connects to the main harness. I don't rule out anything but if that were the case, i don't even see how the engine could run. As i said, i just got the EGC manual and it is 400+ pages. I am trying to read though all of the applicable sections but just cheat a little bit, does anyone know if the is a wire routing diagram?
 
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alldodge

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The wiring diagram for the injectors shows that the common wire for the port side 1,3,5,7 cylinders should be pink and for the starboard side should be pink/white.

If the VP is wired like the Merc (probably is) the pink, pink/white are ignition power and injectors are batch fired (4 at a time). Ground is applied by PCM

Could be VP uses 2 different fused feed lines to power each side. Look forward to MUC input

Merc type which uses all pink/white

Click image for larger version  Name:	555 PCM Injector Batch firing.jpg Views:	3 Size:	77.5 KB ID:	10831993
 

jgerardi

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This is not the same as mine. See picture. However mine has the pink/white on the 1,3,5,7 cyl.
 

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JustJason

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You need to be working on the codes. You have codes for overheat, ECT high voltage, IAT high voltage, electronic throttle control lower than the idle validation switch. All of these codes can be caused by a bad ground. You want to check all of the grounds on the engine and then do a voltage drop test on the ground wire at the ECM to the battery negative terminal with the engine running. The meter shouldn't read any higher than .5 a volt during a voltage drop test, if it's higher, you have a bad ground.
 

muc

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I received that last shop manual i ordered. The EGC manual. Has considerably more information than the PDF version i had for the Gi-G, My boat has the Gi-H. In any event i have noticed there are many references to the DTC resetting. Is there a point where the DTC will no longer show up in stored DTCs other than when they are cleared? The manuals also make many references to the MIL which i do not have.
Another thing i noticed. The wiring diagram for the injectors shows that the common wire for the port side 1,3,5,7 cylinders should be pink and for the starboard side should be pink/white. Mine are opposite. Now i don't see that it could be physically possible to have the two sides reversed based on the routing and position of injector harness's main plug and where it connects to the main harness. I don't rule out anything but if that were the case, i don't even see how the engine could run. As i said, i just got the EGC manual and it is 400+ pages. I am trying to read though all of the applicable sections but just cheat a little bit, does anyone know if the is a wire routing diagram?

Codes will clear on their own. Sometimes it's a certain number of key cycles, sometimes the engine has to run up to temp and cool down a set amount of times. I don't remember the exact way that your ECM works. But I'm pretty sure it's over 30. Some codes will stick until cleared. Why are you concerned about this?
Can't remember if your engine is batch fire or sequential. Sometimes this information (like the number of cycles to clear a code) is in the service manual, sometimes they tell us in class. I would have to check my notes. But it really doesn't matter in this situation.

The 2 wires you are worried about don't matter, they supply power to the injectors and they both get tied together and end up connected to the same place. It's the 8 ground wires that you need to trace. Don't get hung up on the wire colors. What is important is that the ground wire for injector #1 ends up at pin #61 on the ECM, Injector #2 goes to pin #62 ect,etc...

I don't agree with JustJason . You have given a pretty good explanation for why they are there. And the fact that they have not come back after clearing them means that you are probably right to disregard them for now.
 
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