"Making" oil

[csleaver]

7 hours ago, amartin said:

Am I good using the unshielded wires?

 

I recently verified with Indmar technical support on a 2014 model 6.0L that the metal shield with the spring should be removed and discarded when installing the spark plug wires.

[csleaver]

4 hours ago, amartin said:

I was expecting a Schrader valve on the fuel rail, but the "stock" fuel rail for this engine doesn't show one.

Any insight on where it would be?  

Many modern Indmar engines have a fuel pressure sender near the inline filter close to the transmission.  The fuel pressure can be checked using Rinda Diacom, or to check the pressure with a mechanical gauge, Indmar has an adaptor with a Schrader valve that installs in place of the fuel pressure sensor.  Another method to connect a mechanical pressure gauge is to use a 3/8 quick connect fuel testing tee fitting between the fuel pump and the supply line at the fuel tank.  Many high end fuel pressure testing kits will have the Tee fitting and a fuel fitting disconnect tool.

[amartin]

7 hours ago, csleaver said:

I recently verified with Indmar technical support on a 2014 model 6.0L that the metal shield with the spring should be removed and discarded when installing the spark plug wires.

Awesome. Thanks for the reassurance.

7 hours ago, csleaver said:

Many modern Indmar engines have a fuel pressure sender near the inline filter close to the transmission.  The fuel pressure can be checked using Rinda Diacom, or to check the pressure with a mechanical gauge, Indmar has an adaptor with a Schrader valve that installs in place of the fuel pressure sensor.  Another method to connect a mechanical pressure gauge is to use a 3/8 quick connect fuel testing tee fitting between the fuel pump and the supply line at the fuel tank.  Many high end fuel pressure testing kits will have the Tee fitting and a fuel fitting disconnect tool.

So likely not just a “rent / borrow  a fuel pressure gauge from Autozone” solution…

[amartin]

Turn out that there is a valve on the fuel rail. I guess the procedure is to hook it up and monitor pressures through entire power on to full throttle and back down sequence?  Should stay constant, right?

[amartin]

So trying to get a step ahead…. I assume that the fuel rail has to come straight up a ways to get the injectors out of the manifold. Everything looks straightforward to clear / move with the exception of the relays / main fuse on the bottom right of this picture. Any insight / experience from the crew?

Also - I went ahead and pulled the a couple of plugs while putting the new wires in. First picture was cylinder “H” from the prior set of plugs.  Second is from “E”. Both look pretty similar, but I was surprised to see the amount of carbon on both at the top of the treads / body. 

[amartin]

I am getting 60 psi after entering the code to energize the fuel pump. It stays there for a few seconds and then starts to drop off. Same behavior after running the engine.   I am alone so didn’t runt at WOT to get that data point, but not sure that it matters at this point?

This points to a leaky injector, right?

[amartin]

I know that I am talking to myself, but…

any tick to getting these electrical connectors off the injectors?  I don’t want to pull too hard and cause new problems, but they won’t budge. With or without the green tab pulled back. 

[amartin]

To finish off my monologue…😁

Got everything out and apart. Will get the injectors tested and cleaned this week. Other than doing the reverse of what I just did, and suggestions for reassembling?  Any oring lubricant needed?  Will the file system prime itself?  Any type of cleaning, other than the injectors, that I should do before reassembly?

Will follow up with an oil change to get any fuel out of it and then hopefully back in action. 

[amartin]

Initial reports from the injector shop are that none of the injectors were leaking when I brought them in.  I am not sure how sensitive these injectors are, but is there any realistic chance that they were leaking when installed in the boat, but not on the bench.   I wont have final results (pre and post cleaning flow mapping) until Thursday.

To recap how we got here:

• Found significant fuel in the oil.
• Performance was not noticeably impacted.
• Compression test on all 8 cylinders was good.
• Changed plugs and wires and can achieve 43 mph @ 5300 RPM.  Idle seemed smoother after new plugs.
• Fuel Pressure goes to 60 psi at "key on".  Also maintains 60 psi at idle.  I did not get a chance to test pressures at WOT.
• Fuel pressures drop off after pump shuts off and bleeds down to about 20 psi after about 2-3 minutes.
• Pulled injectors and am awaiting their return.

If I assume that they were not leaking, any insight on what could be causing the fuel pressure drop after pump shutoff and the fuel getting into the oil symptoms?  I will check fuel pressure again once I have re-assembled, but hoping to get ahead of the curve on the troubleshooting.

[Steve B.]

I am going with no on this one. If there was a bad one they'd know. I think you have something else going on. Obviously follow thru and see where you are after the re-install. Sometimes trying to resolve an issue reveals the real culprit.

Did you end up replacing the pressure regulator ? 

Edited July 25, 2023 by Steve B.
Added thought

[Steve B.]

Still thinking about this amartin, does this fuel injection system have some kind of return to the tank? I wish I knew if that loss of pressure after key off was typical or not. Keep us posted,

Steve B.

[amartin]

11 hours ago, Steve B. said:

I am going with no on this one. If there was a bad one they'd know. I think you have something else going on. Obviously follow thru and see where you are after the re-install. Sometimes trying to resolve an issue reveals the real culprit.

Did you end up replacing the pressure regulator ? 

Had not considered the regulator up to this point.

9 hours ago, Steve B. said:

Still thinking about this amartin, does this fuel injection system have some kind of return to the tank? I wish I knew if that loss of pressure after key off was typical or not. Keep us posted,

Steve B.

I don't really know much either!  The only part of the fuel system that I have looked at is the fuel rail / injectors up to this point.

[justgary]

2 hours ago, amartin said:

Had not considered the regulator up to this point.

Leakdown after power down is expected.  I'm not sure if the regulator or the pump itself is to blame, but the pressure won't hold indefinitely.  Perhaps @csleaver can help pinpoint a time range for the pressure change.

[amartin]

6 minutes ago, justgary said:

Leakdown after power down is expected.  I'm not sure if the regulator or the pump itself is to blame, but the pressure won't hold indefinitely.  Perhaps @csleaver can help pinpoint a time range for the pressure change.

I was struggling with that.  The system cant stay pressurized forever.  The leak down after power down seemed to match the leak down after pump shutoff several seconds after "key on" (entering the code n the lock screen.  I should have videoed it to get a better perspective of the time / rate of drop.

[csleaver]

I don't know if there is a hard rule or specification (I would have to look into it), but a pressure loss at key off of more than 80% within two minutes would make me concerned and pressure loss of less than 20% within 5 minutes seems pretty normal. 

Two pressure gauges can be used with a shutoff valve between them to see if pressure loss is associated with the injectors or with the fuel pump regulator, assuming there are no external fuel leaks.

Edited July 26, 2023 by csleaver

[amartin]

8 minutes ago, csleaver said:

I don't know if there is a hard rule or specification (I would have to look into it), but a pressure loss at key off of more than 80% within two minutes would make me concerned and pressure loss of less than 20% within 5 minutes seems pretty normal. 

Two pressure gauges can be used with a shutoff valve between them to see if pressure loss is associated with the injectors or with the fuel pump regulator, assuming there are no external fuel leaks.

This is good guidance.  I don't believe that it ever lost 80% within 2 minutes, as the pressure seemed to stabilize about 25 psi for a long time.  Less than 20% within 5 minutes was certainly not achieved though.  I wonder if I can "dead head" the pressure gauge into the fuel line off of the pump before I hook up the fuel rail to isolate the behavior of the regulator vs the injectors... 

If the leak back is through the regulator, would that have any impact on fuel getting into the oil? 

[oldjeep]

That is the weird thing.  There are only 2 ways that I can think of to get fuel in oil with a port injected engine.  Leaky injectors or cylinders that are not firing.

 

[Steve B.]

Thinking about it some more, I'm wondering how much fuel is getting in there and how quickly. Is there more fuel in the oil than just one injector could leak after shut-off?

Like mentioned about there can really only be 2 ways to get fuel in the oil.

[Woodski]

@amartin - Quickly scrolling the thread,  you've done a compression test, did you do a leak down test?  A compression test can be deceiving.  Have you looked at the PVC tube to see if there is much / any blow by when the engine is running?  Plug H is certainly questionable, and may not be firing (as noted above).  Another possible path could be a bad intake manifold gasket.  Question - how many hours did it take to end up with 10 qts in the pan (is it 50 hours based on post #1?).

[oldjeep]

How could an intake gasket result in fuel in oil?

[amartin]

1 hour ago, Woodski said:

@amartin - Quickly scrolling the thread,  you've done a compression test, did you do a leak down test?  A compression test can be deceiving.  Have you looked at the PVC tube to see if there is much / any blow by when the engine is running?  Plug H is certainly questionable, and may not be firing (as noted above).  Another possible path could be a bad intake manifold gasket.  Question - how many hours did it take to end up with 10 qts in the pan (is it 50 hours based on post #1?).

I did a compression test, but no leak down test. 10 qts of fuel/oil came out of the oil pan after about 39 hrs since the previous fluid change.  I noticed lower oil pressures and higher oil levels so I changed before the normal 50 hr interval.  I have not touched the pcv tube prior to removing it to get the fuel rail / injectors out. 

[amartin]

Injector test results are pretty mundane to my untrained eye, but this is my first experience with testing / cleaning injectors. Looks like the flow rates went up a bit after cleaning, but there certainly does it appear to be a smoking gun here…

 

sorry - can’t seem to figure out how to rotate the picture…

[oldjeep]

Yeah - nothing there

[amartin]

On 7/26/2023 at 10:32 AM, csleaver said:

I don't know if there is a hard rule or specification (I would have to look into it), but a pressure loss at key off of more than 80% within two minutes would make me concerned and pressure loss of less than 20% within 5 minutes seems pretty normal. 

Two pressure gauges can be used with a shutoff valve between them to see if pressure loss is associated with the injectors or with the fuel pump regulator, assuming there are no external fuel leaks.

Refreshed injectors re-installed and tested.  Here are my pressure results after shutoff:

Minutes since shutoff   Pressure

• 0                                     60
• 1                                     38
• 2                                     32
• 3                                     28
• 4                                     26
• 5                                     24
• 6                                     22
• 7                                     20
• 8                                     19
• 9                                     18
• 10                                    18
• 20                                    12
• 30.                                   10

While I don't have evidence of the results prior to removing the injectors, these "feel" similar.  The first key on held pressure a bit better, but that is likely the result of the trapped air in the system.

To frame it in @csleaver's parameters, 47% drop in 2 minutes and 60% drop in 5 minutes.

Any thoughts?  Seems to me that I just did some preventative maintenance, which is fine, but still have or had the mystery of the fuel in the oil.

Edited July 28, 2023 by amartin

[amartin]

Here is a video sf a start / stop sequence...

https://www.instagram.com/stories/hfialum/3157165684882991435/?hl=en

(I hope that I dd that right - I am not much of an instagramer...)