HELP 2005 5.0 MPI OVER REV

[QBhoy]

Hi. Most have covered what I was going to say…but out with the ecu being wrong and for some reason allowing those rpms…no way you are getting those rpms in reality. I’ve the same engine (all be it, with a cam and exhausts)…it will limit at almost exactly 5130-5150 rpm, verified exactly by the vessel view mobile read out. If you give me details of your gear ratio on the alpha, I could likely compare some of my real world exact recorded data for speed and rpms, from mine.
I’ve a 1.47 ratio and taken lots of exact data from trials with far too many props.
A couple of examples might be useful to you if you’re interested.
Here is one or two.
21” laser 2
5140/5150 on limiter occasionally
67.6 mph gps

20” enertia
5150 on limiter
64/65 mph gps

19” tempest plus
5150 on limiter
61/62 mph

The above is from a fairly specialised hull to be fair. With a apex step and a pad. Not sure if the actual HP…but likely around 300ish.

Anything prop wise from 21” and above is useless though. The 5.0 doesn’t have the guts to make it perform down low in the rpms. I usually run a 19 or 20”.

 

[Regal_2250]

Hi. Most have covered what I was going to say…but out with the ecu being wrong and for some reason allowing those rpms…no way you are getting those rpms in reality. I’ve the same engine (all be it, with a cam and exhausts)…it will limit at almost exactly 5130-5150 rpm, verified exactly by the vessel view mobile read out. If you give me details of your gear ratio on the alpha, I could likely compare some of my real world exact recorded data for speed and rpms, from mine.
I’ve a 1.47 ratio and taken lots of exact data from trials with far too many props.
A couple of examples might be useful to you if you’re interested.
Here is one or two.
21” laser 2
5140/5150 on limiter occasionally
67.6 mph gps

20” enertia
5150 on limiter
64/65 mph gps

19” tempest plus
5150 on limiter
61/62 mph

The above is from a fairly specialised hull to be fair. With a apex step and a pad. Not sure if the actual HP…but likely around 300ish.

Anything prop wise from 21” and above is useless though. The 5.0 doesn’t have the guts to make it perform down low in the rpms. I usually run a 19 or 20”.

How do I determine the ratio, I guessed it's the 1.62 or whatever but I'm uncertain. I checked today and cycle the rpm setting on the back of the Guage and rpm seems to have normalized at 600rpm idle. I guess next step is again put in water. The ECM is new to me I bought online, when I got it my Friend told me it's a ReFlash, so I don't know of that's NEW or not but condition wise looks brand new. My original ECM was an 865926, which was ruled to be dead. My dealer told me the part number I needed was 866189t01, 866189t02, 866189t03, 866189t06. I purchased what was sold to me as a 866189t06 but the part number is no where to be seen on the ecm itself. It does say 5.0 Alpha, 8M2003666, 8M2001111 8M0079860. and it also says ECM 0718 01-13-2019. Then there is a tag that says 24 motoflash 16g. my old one was ECM0501 01-04-2005.so alot going on that I can't reference. I guess to confirm if they sold me the 866189T06 I'll have to pay someone to plug into again to see th Cal#. That said it starts my boat, and it runs. Maybe the tach was the issue. But I am still having an issue when I try to start the boat and the fuel pumps are not coming on and that's where all this problem stated. I hit the relay with screw driver and it starts up. I'm still super sketched out about all this as I spent bow almost 5K getting this far to still have remnants of this same problem. One thing for sure, 5 months ago I wouldn't have half the understanding of all this as I do now lol. Just wish I was a little more mechanically inclined so I could figure this out and wish I knew more about electrical my ability is limited so I am really appreciative of all the advice. I am hoping now that the high rev was a tachometer fluke and praying I just have a sticky relay in addition to the burned out ECM. I'll pick up a new one and try that. If this starting issue persists with no fuel pump we'll than I am f%%%Ed. I won't know what else to do

 

[Scott Danforth]

you turn the input shaft and count the rotations.

or on the alpha, look at the bottom of the stock sticker (if its still there). in small print on the bottom is the gear ratio.

however you need to verify your tach first. no need to perceverate on the cal. just verify RPM's at 3000 and 4500 RPM

 

[Regal_2250]

you turn the input shaft and count the rotations.

or on the alpha, look at the bottom of the stock sticker (if its still there). in small print on the bottom is the gear ratio.

however you need to verify your tach first. no need to perceverate on the cal. just verify RPM's at 3000 and 4500 RPM

So I shouldn't bother paying to see if the calibration is correct ? If she's running ok then don't worry about it ?

 

[Scott Danforth]

So I shouldn't bother paying to see if the calibration is correct ? If she's running ok then don't worry about it ?

I wouldnt waste the beer tolkens

 

[QBhoy]

So I shouldn't bother paying to see if the calibration is correct ? If she's running ok then don't worry about it ?

I’d buy a VesselView mobile for sure. That will tell you what rpm you are really doing. Among lots of other things.
See if you can get details about the new ecu and what’s been done to it. Probably not the case that you’re seeing genuine high rpms like that I’d say. But make sure. It won’t last long if it is doing that.
About the not starting thing. My relays can play up on mine…but when they do…the fuel pump always comes on and not affected. It just doesn’t turn over and clicks when they do. Pump is never affected. Yours sounds more like a in gear or kill switch issue

 

[Scott Danforth]

remember, the VF-4 relays you guys are talking about are $1.34 each or less. both Merc and Volvo spend actually less than $.40 each at volume

they are a mechanical device that is made by the cheapest Thailand citizens in the world and then sold globally.

 

[Regal_2250]

I’d buy a VesselView mobile for sure. That will tell you what rpm you are really doing. Among lots of other things.
See if you can get details about the new ecu and what’s been done to it. Probably not the case that you’re seeing genuine high rpms like that I’d say. But make sure. It won’t last long if it is doing that.
About the not starting thing. My relays can play up on mine…but when they do…the fuel pump always comes on and not affected. It just doesn’t turn over and clicks when they do. Pump is never affected. Yours sounds more like a in gear or kill switch issue

I have already isolated the kill switc, and the gear select no issues at all there

 

[Regal_2250]

remember, the VF-4 relays you guys are talking about are $1.34 each or less. both Merc and Volvo spend actually less than $.40 each at volume

they are a mechanical device that is made by the cheapest Thailand citizens in the world and then sold globally.

Can I get these on Amazon?

 

[Regal_2250]

Can I get these on Amazon?

I was told they are 60 bucks

 

[Scott06]

How do I determine the ratio, I guessed it's the 1.62 or whatever but I'm uncertain. I checked today and cycle the rpm setting on the back of the Guage and rpm seems to have normalized at 600rpm idle. I guess next step is again put in water. The ECM is new to me I bought online, when I got it my Friend told me it's a ReFlash, so I don't know of that's NEW or not but condition wise looks brand new. My original ECM was an 865926, which was ruled to be dead. My dealer told me the part number I needed was 866189t01, 866189t02, 866189t03, 866189t06. I purchased what was sold to me as a 866189t06 but the part number is no where to be seen on the ecm itself. It does say 5.0 Alpha, 8M2003666, 8M2001111 8M0079860. and it also says ECM 0718 01-13-2019. Then there is a tag that says 24 motoflash 16g. my old one was ECM0501 01-04-2005.so alot going on that I can't reference. I guess to confirm if they sold me the 866189T06 I'll have to pay someone to plug into again to see th Cal#. That said it starts my boat, and it runs. Maybe the tach was the issue. But I am still having an issue when I try to start the boat and the fuel pumps are not coming on and that's where all this problem stated. I hit the relay with screw driver and it starts up. I'm still super sketched out about all this as I spent bow almost 5K getting this far to still have remnants of this same problem. One thing for sure, 5 months ago I wouldn't have half the understanding of all this as I do now lol. Just wish I was a little more mechanically inclined so I could figure this out and wish I knew more about electrical my ability is limited so I am really appreciative of all the advice. I am hoping now that the high rev was a tachometer fluke and praying I just have a sticky relay in addition to the burned out ECM. I'll pick up a new one and try that. If this starting issue persists with no fuel pump we'll than I am f%%%Ed. I won't know what else to do

There is nothing wrong with a properly done reflash. If it wasn‘t done right you need to go back to who you got it from, but from everything shown here it looks fine.

if you have to tap a relay to get to to work replace it or clean the connections feeding power to it. Have you taken it out and looked at the connections?
other than an inaccurate tach it seems like past issues are making you nervous. Put the boat in the water and verify wot with your friends tach on it…

ratio is on port side of drive near upper lube plug. Its in sticker and stamped in drive underneath.

 

[Scott Danforth]

Can I get these on Amazon?

Newark or digikey or direct from TE or Hella

 

[Regal_2250]

There is nothing wrong with a properly done reflash. If it wasn‘t done right you need to go back to who you got it from, but from everything shown here it looks fine.

if you have to tap a relay to get to to work replace it or clean the connections feeding power to it. Have you taken it out and looked at the connections?
other than an inaccurate tach it seems like past issues are making you nervous. Put the boat in the water and verify wot with your friends tach on it…

ratio is on port side of drive near upper lube plug. Its in sticker and stamped in drive underneath.

Relay and plug seem clean. I'll definitely put in water for another go, and yes she's made me super nervous. 28K and I got 1 ride in it. Near another 5 K and still not quite clear lol.

 

[Regal_2250]

So today I went our to the boat, turned the key and age started up fine. Cycle the key and fuel pump coming on and off no problem. I decided to bench test the fuel pump relay and it's opening and closing no problem, showing 77OHm resistance and has continuity. I reinstalled the relay and then she would not start the fuel pump. Jiggle some wires around and she starts. Remove the relay and reinstall it and she won't start. I applied a little pressure where the fuel pump relay wires went into the main harness loom and the fuel pump started so I was hoping there was an issue there. I pulled back a bunch of tape and went on the hunt, bending and wiggling anything and everything at this point for the life of me I couldn't get her to restart. Figured I was down right up **** creek again. Decided to put it all back together put the relays in their holders etc, turn the key and the pos starts. Don't know what to do...do I have an electrical problem? Is there a chance I can do damage do a brand new 3400$ ECM?

 

[Scott06]

So today I went our to the boat, turned the key and age started up fine. Cycle the key and fuel pump coming on and off no problem. I decided to bench test the fuel pump relay and it's opening and closing no problem, showing 77OHm resistance and has continuity. I reinstalled the relay and then she would not start the fuel pump. Jiggle some wires around and she starts. Remove the relay and reinstall it and she won't start. I applied a little pressure where the fuel pump relay wires went into the main harness loom and the fuel pump started so I was hoping there was an issue there. I pulled back a bunch of tape and went on the hunt, bending and wiggling anything and everything at this point for the life of me I couldn't get her to restart. Figured I was down right up **** creek again. Decided to put it all back together put the relays in their holders etc, turn the key and the pos starts. Don't know what to do...do I have an electrical problem? Is there a chance I can do damage do a brand new 3400$ ECM?

LFW... Loose F... Wire. In machines at work I have seen where we have to zip tie the cube relays into the socket.. Also could be a weak or corroded engine ground. I doubt you did anything to the ecu that would likely work or not. Intermittent is likely corrosion in wiring connections and resultant voltage loss.

Are you sure it is getting a good 12 v from the key? I would think dash and key, possibly cannon plug on engine would be likely spots for voltage loss.
Really need to start at battery checking all connections for tightness corrosion and voltage drop with voltmeter or test light...in a marine environment these are common problems as long as you can do the work yourself its just a PITA

 

[Scott Danforth]

My guess bad terminal in the relay socket

 

[Regal_2250]

LFW... Loose F... Wire. In machines at work I have seen where we have to zip tie the cube relays into the socket.. Also could be a weak or corroded engine ground. I doubt you did anything to the ecu that would likely work or not. Intermittent is likely corrosion in wiring connections and resultant voltage loss.

Are you sure it is getting a good 12 v from the key? I would think dash and key, possibly cannon plug on engine would be likely spots for voltage loss.
Really need to start at battery checking all connections for tightness corrosion and voltage drop with voltmeter or test light...in a marine environment these are common problems as long as you can do the work yourself its just a PITA

What is the cannon plug

 

[Scott Danforth]

What is the cannon plug

big round plug made by cannon industries

 

[Regal_2250]

Oh, the one on the back left of the motor round pin, I assume provides power to the harness?

 

[Regal_2250]

Yesterday I started tearing tape away from the relays back into the harness and checking wires after successfully bench testing the relays and determined they were good. Today I put all the relays out of the way and made them static so I could move things around without moving the harness. When I remove the fuel pump relay and put it back in, the pump won't start. I take a flat head screw driver and just wedge in between the relay and the socket base, just enough to see the green weather seal and the pump starts every time. I presume the issue is in the connection between the relay teeth and the receiving points on the female side. For now it appears that I have determined a way to replicate and rectify the issue. I will re tape and put the loom back around, ensure the female receptacles are tighter and send this baby for another sea trial. Hoping I'm on the other side of it. Also a qualified pal offered me to send him my harness and he will rebuild it and check it for free 100 percent check through. Maybe something I'll consider. Thanks everyone.