Closed Cooling System on Port Engine Running Hot(ter)

tpenfield

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Sorry to hear your having the issues, but more tools makes me giddy :D :D :D

I know . . . I am really excited about the Diacom software. :glee: :glee: :glee: That should be way cool, even though it is only an MEFI 1 and quite Neanderthal as compared to later versions of ECM's.
 

achris

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If you need help with the software, let me know. Been running is for a few years now. It's quite easy, but there are a few 'gotcha's....
 

tpenfield

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I got a package today :) :) :)
IMG_7950.jpg


Got to load it up to my laptop and get ready to test it out. It came with the special cable for Windows 10, which is extra long and I have a USB extender cable.

My hopes are that I can have the laptop reach the helm so I can 'record' some of the stats while the engines are under load. I believe it will record about 50 seconds of info from the ECM.
 
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alldodge

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Look forward to seeing what it finds. Might tell me I should have bought what you did instead of the scanner a couple years back
 

tpenfield

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Interesting thing is that the product information does not mention the cable, but it is good that they provide it.

AD - I looked at the pricing of the code reader and thought the full computer software was a better deal, even though more $$$.
 

tpenfield

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Chris -

I ran the engines and recorded some data Not sure if I can send them in a PM or if I will have to send a regular email. I'll try a PM first.

Nothing earth shattering, but the 2 engines generally have the same stats for MAP, Injector pulse, etc. They both say "Lean" on the fuel Mixture, but I am not sure with the MEFI-1 controllers it is a valid indication, even though I know the engines are running lean.

Here are samples of the screen display from the controllers.

Port

PortEngine.png

Starboard Engine

StarboardEngine.png


also, I could not find a Schrader valve on the fuel rail. I found a fitting and plug that looks like it would be able to take a Schrader valve, but not valve . I assume the Schrader valve would be a male, as the pressure gauge I have has the female fitting to go into a male Schrader.
:noidea:

So, I was able to check the engine parameters, but not the fuel system pressure (VST system)

BTW - NO CODES on either MEFI
 

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alldodge

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There isn't much resolution on the MEFI 1, I had similar results with my scanner and I was running rich.

Mine had a Shrader valve in it where your probably seeing the plug. My guess is the previous owner may have installed one there. Mine came from a twin engine scarab out of NY which was going to blowers
 

tpenfield

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I sent the files off to Chris for his input. The data did not show anything major (too me), but we'll see.

I'm thinking at this point that the VST is getting tired.

FWIW - I also ran a wicked high concentration of fuel injector cleaner through the port engine today.
 

tpenfield

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Just catching everyone up from yesterday . . . based on the recordings from the Diacom software, Chris thinks that I should check the IAC's. (Thanks, Chris :thumb: )

So, that will be on today's list of things to do (in addition to boat, beach and beer) :)
 

tpenfield

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OK, I removed, cleaned and reinstalled the IAC. It did not look bad at all. A bit of crud was in the breather tube leading to the IAC, but not bad.

The boat runs the same - about a 20 F degree difference at idle speeds and a 10 F degree difference at cruising speeds. Still need to verify the fuel rail pressure.

Next weekend, I'll have some more time to mess with it. My biggest concern is the lean condition as evidenced by the spark plugs.
 

achris

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Thanks for looking at the Diacom recordings. Swap the spark plugs? :noidea: not sure if that is what you are referring to . . .

:laugh::laugh::laugh::lol::lol: No, not the spark plugs, the IACs. I still don't like that the timing at idle was jumping around so much. When my IAC failed, it froze in one position, and the ECU used the timing to control the idle speed. The engine idle also sounded 'weaker', just slightly 'off' from it's normal sound. When I put the Diacom on it, the idle timing was jumping around just like yours. I pulled the IAC and fixed it, and the idle timing went back to a solid 8?BTDC and the engine sounded more steady, stronger.

Just a thought, that's all.

Chris......
 

tpenfield

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Yea, I eventually realized that is what you meant :) My bad :facepalm:

Since both engines seem to have the spark advance jumping around, I am wondering if both IAC's are going bad. :noidea:

When the engines were warming up the IAC count only got into the single digits (like 7 or 8) not sure if that is indicative of the IAC wearing out / freezing up.

Another question though, once the engine is above idle speeds does the IAC even matter?
 

achris

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...Another question though, once the engine is above idle speeds does the IAC even matter?

That's part of what I was alluding to. Once the TPS shows above the defined 'idle range' parameter, the IAC is closed off and the throttle body and injection pulse waves take control of engine speed. The important part is that the IAC is closed. Now, if the IAC is sticky/stuck it will allow extra (unmetered) air into the intake manifold, and that makes the mixture leaner than the ECU has been claibrated for. You already have the mixture set in the ECU to 'Lean'. More air will make the mixture 'Too lean'... Too lean or not too lean, that is the question.

:behindsofa:

Sorry, couldn't let it pass.

:D Chris...........
 

tpenfield

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Lean on me . . . Actually, I am leaning on you :D . . . for advice :)

I am wondering if there is a way to set the ECU to not be 'Lean' :noidea:

I was also reading in some other forums, etc., that if there is a vacuum leak somewhere, than you can get similar symptoms.
 
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