5.7 MPI Misfires Under Load

tpenfield

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@ksvista - It is best to have a single thread with your engine issue, rather than creating a new threads as you work to resolve the issue.

I have taken a quick look at your engine data. There are trouble codes, but they are not visible in the recording file. Please take a look at the codes and maybe post a screen shot of what they say. I'll look some more at the data, but a best practice is to remedy all of the engine codes and then see if the issue is still present.

Meanwhile I will see about combining your threads into one.
 

tpenfield

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@ksvista

A few quick comments on the engine data . . .

Engine temperature is quite low (120˚F should be in the 160 range)

Timing advance is going up when you throttle up as it should, but then stays up at 24˚ after you throttle down. It would be interesting to see what the codes are. (not sure if you have posted them previously)
 

muc

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Post the numbers from the injector balance test.
Post the engine serial number.
Post a pict of the ECM stickers.
Post the Diacom files, snapshots of the screen doesn’t really show much.
 

tpenfield

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Post the numbers from the injector balance test.
Post the engine serial number.
Post a pict of the ECM stickers.
Post the Diacom files, snapshots of the screen doesn’t really show much.
@muc I have a copy of the Diacom files that I can send you.
 

muc

"Retired" Association of Marine Technicians...
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Post the drive and transom serial numbers along with a pic of the ECM sticker. I can usually link an engine with that.
Post the year make and model of the boat.
I haven't seen any REC files posted. I personally don't know how to post them, I just know it can be done because others have done it. And you might get more help if you post them to this tread rather then PMing them. Maybe someone with greater computer knowledge can help with this?

A note on Diacom, anyone can download the program from the https://www.rinda.com/update.htm website and follow along as we try to diagnose. I have had to do this when a customer dropped my laptop in the lake while I was on a service call. He had a laptop on board and we just downloaded the update ---- worked fine.


Here is my recommendation on how to do the recording.

Start with a cold engine and the boat in the water.

1. Connect Diacom

2. Turn on batt switch, turn on key switch -- but don't start engine

3. Start Diacom recording -- let run for 30 seconds to one minute

4. Start engine

5. Check that Diacom is still recording, it's not uncommon for it to have lost communication during starting. If it did, save that recording and start another one.

6. Run the boat gently at idle to 1500 RPM until up to operating temp

7. Run the boat up to full speed --- take your time, looking to get data here so advance the throttle slowly (spend one to two minutes) now slow back down to minimum wake and idle in neutral for awhile. Use the trim as you normally would.

8. Do a "ski start" -- full throttle all the way to full speed and trimmed out, now back to idle fairly quickly.

9. Drive boat back to the dock/ramp and shut off

10. Stop recording and name the files
 

ksvista

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Mar 1, 2023
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Post the drive and transom serial numbers along with a pic of the ECM sticker. I can usually link an engine with that.
Post the year make and model of the boat.
I haven't seen any REC files posted. I personally don't know how to post them, I just know it can be done because others have done it. And you might get more help if you post them to this tread rather then PMing them. Maybe someone with greater computer knowledge can help with this?

A note on Diacom, anyone can download the program from the https://www.rinda.com/update.htm website and follow along as we try to diagnose. I have had to do this when a customer dropped my laptop in the lake while I was on a service call. He had a laptop on board and we just downloaded the update ---- worked fine.


Here is my recommendation on how to do the recording.

Start with a cold engine and the boat in the water.

1. Connect Diacom

2. Turn on batt switch, turn on key switch -- but don't start engine

3. Start Diacom recording -- let run for 30 seconds to one minute

4. Start engine

5. Check that Diacom is still recording, it's not uncommon for it to have lost communication during starting. If it did, save that recording and start another one.

6. Run the boat gently at idle to 1500 RPM until up to operating temp

7. Run the boat up to full speed --- take your time, looking to get data here so advance the throttle slowly (spend one to two minutes) now slow back down to minimum wake and idle in neutral for awhile. Use the trim as you normally would.

8. Do a "ski start" -- full throttle all the way to full speed and trimmed out, now back to idle fairly quickly.

9. Drive boat back to the dock/ramp and shut off

10. Stop recording and name the files
Thanks. Unfortunately, my Diacom was rented and had to be returned after a week. Currently I only have the (4) recordings and error export
 

muc

"Retired" Association of Marine Technicians...
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Thanks. Unfortunately, my Diacom was rented and had to be returned after a week. Currently I only have the (4) recordings and error export
Post those and the other info and we can try to help.
 

ksvista

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Post those and the other info and we can try to help.
Unfortunately, I think I can only post snips from Diacom IBOATS does not allow .rec file extensions. Unless someone can help there also!
 

tpenfield

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I have the recordings and can forward them to you @muc . PM me your email, if you would like.

I tried to post some Diacom files last year and it wouldn't take them either in a post or a PM.
 

muc

"Retired" Association of Marine Technicians...
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I have the recordings and can forward them to you @muc . PM me your email, if you would like.

I tried to post some Diacom files last year and it wouldn't take them either in a post or a PM.
Thanks for the offer. Would love to look at them once we get the serial number and ECM figured out.
I did notice that you pointed out a low temperature problem. Probably be good for the O.P. To get that resolved.
 

ksvista

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Thanks for the offer. Would love to look at them once we get the serial number and ECM figured out.
I did notice that you pointed out a low temperature problem. Probably be good for the O.P. To get that resolved.
I'll be out there this weekend to get the ecm info. Any luck on reading the diacom files? thanks again
 

muc

"Retired" Association of Marine Technicians...
Joined
Jul 7, 2004
Messages
2,143
I'll be out there this weekend to get the ecm info. Any luck on reading the diacom files? thanks again
Would love to look at them once we get the serial number and ECM figured out.

You can use.
Dropbox
Onedrive
Googledrive
to post these files so we can all see, just upload them and post the link here
 
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