5.0 OSi-E low power, unable to hit RPM & WOT.

[lonewolf41]

SO I got to looking at the data again last night and the MAP voltage stuck out to me. The manual says it should be 1.0-1.5 at idle. Mine was right at 2.0. So I was thinking maybe a bad MAP sensor or vacuum leak. I checked the vacuum at idle and it was 16.0-16.5 in Hg. Seemed a little low, but the manual says 14-19 is normal.

Today I noticed an odd ticking when I bumped the throttle. It was about 3-4 quick ticks in maybe a tenth of a second. It sounds similar to the injector noise, but I unplugged the 2 injectors closest to where I thought it was coming from, but it didn't go away. I have a video that I think you can hear it. https://drive.google.com/open?id=14pcblhahuYiiE0hRDKoSDN7gaiOY-5bV . It is pretty noticeable at 4-5 seconds and about 14-16 seconds.

I may see about a MAP sensor or at least put mine on a vacuum pump ad see what it reads. The buttlerfly on the throttle body was pretty dirty. I cleaned it off, but I wonder if some of that could have gotten to the MAP sensor and is causing issues. It is easy enough to remove that I will probably do that and just see what it looks like and see if I can clean it.

I talked to the local Volvo shop here and they said I had done everything they would do. He did say to lower the oil level some as there was a bulletin about high oil level causing problems so I have done that. I welcome any other suggestions.

Thanks.

 

[alldodge]

Wow Iboats been down for me for some time

I have the adx definitions for mefi 1 thru 4 and did try 4, but got less info
I'm see the stuff in the pic stay there, and not much of any change

 

[lonewolf41]

AllDodge, I have tweaked it some. Maybe it changed it. I thought it just affected how it was displayed, but maybe not. I know very little about the software...just fumbling my way through it. Try this one. It is the one I have loaded up.

 

[alldodge]

Its an ADX file which I have the mefi 4 adx, I'll need the XDL file to run in scanner pro

 

[lonewolf41]

Its an ADX file which I have the mefi 4 adx, I'll need the XDL file to run in scanner pro

Sorry, I misunderstood. The XDL files are in the zip file on post 18.

 

[alldodge]

Your MAP is staying high even when the TPS goes lower. Injector pulse responds to MAP as it should, so as TPS reduces and MAP stays up until the MAP starts to drop. Ignition voltage is also lower then where it should be at 12.9 to 13.2, and I would like to see closer to 14

 

[lonewolf41]

So do you think there is an issue with the alternator or voltage regulator? I have looked in both the EFI diagnostic manual and the Engine manual and could not find a test procedure for testing the alternator. Is there a procedure for testing it? If so, where would it be?

As far as the MAP and TPI, I noticed that the MAP seemed to stay high even when closing the throttle. The MAP seemed to follow the RPM more than the TPI which seemed wrong to me, but I am not sure how to check it. I did take the MAP out and it looked OK. I also put it on my handheld vacuum pump and as I applied vacuum, the voltage went down as expected. I got it down to about 1V with about 21 in HG vacuum. That tracks with the 2V I was getting at 16 in HG of engine vacuum. So it seems to be reading the manifold pressure correctly based on the vacuum and voltage readings I am getting. It is strange that the manifold pressure stays high even when closing the throttle. I mean the fact that the throttle can go from 50% to 100% (100% increase) and the MAP only changes .6V (18% increase) just seems wrong, but I am not sure what is causing it or where to look. That is part of the reason I thought about a vacuum leak, but the vacuum was in spec.

Thanks for sticking with me.

 

[alldodge]

I don't see you having a vacuum leak, and a leak would be my only thought of the MAP staying high unless its not functioning correctly. Your checking the high and the low of the MAP but not sure of the middle.

The MAP information feeds into the ECM fuel table. The fuel table is the set points for injector pulse width. As the TPS closes, the MAP is keeping the pulse width at about the same amount. So as the TPS closes the mixture should be getting richer

If it was mine I would replace the MAP with what I'm seeing so far

 

[TAEILLO]

What was the outcome I’m having the same problem

 

[TAEILLO]

My issue is exactly the same and change everything and more leaning towards electrical when I trim my drives I hear a static noise, I’m not a mechanic but worked on this boat consistently for four weeks and is becoming very in tune with these engines and I believe it’s an electrical low voltage spikes that is causing the eco to trigger false readings, currently I have the boat to a certified mercury dealer and their mechanic has changed more fuel parts costing $$$ and still no change I will be getting the boat back this week and changing the alternator, let me know if you changed something and it worked.

 

[lonewolf41]

I have not fixed it yet. I am still working on it...although I am getting close to throwing in the towel. My next move is to install a new MAP sensor. I am also going to look into the lowish voltage if I can find a test procedure. Definitely interested in hearing if you find something that works. I will post back if I ever get this thing working correctly. Makes me sad I sold my last boat with the carb setup. So easy to work on and troubleshoot...not that I ever had a single problem with it.

 

[Saline Marina]

So when you go out to the water can you see a live data display as shown in post #19?

I can't see the scans nor replay the data but I would look at knock retard to see if there's any activity.

Make sure the TPS can read the entire range of 0 to 100%.

Make sure the MAP sensor responds to all throttle inputs.

When you reach the point where you are mechanically out of engine power, do the MAP and TPS respond and is it calling out a larger pulsewidth as you go deeper into the throttle?

 

[alldodge]

lowish voltage if I can find a test procedure

Measure voltage at the 50 amp breaker on the motor. You should see 14.5V with it running about 1500 rpm

 

[lonewolf41]

I finally was able to take the boat out to see what, if any, difference the changes I made had on the motor. I removed some oil to where the level was about half way between the add and full marks. I also replaced the MAP sensor. I can't tell that there is much if any change in performance. I may have gained 200 more RPM (now maxes out about 4450), but it still seems to behave similarly where I can close the throttle and nothing really changes in the motor until it goes down to about 50% open. I recorded some more runs and they are zipped and attached to this post.

I can say definitively that the throttle/TPS is reading correctly. I can sit there (in the driveway, key on, motor off) and watch the throttle angle track right along as I open and close the throttle by hand and it also matches what I am doing while recording out on the water. There are not many other sensors left. I have not tried resetting the distributor, but it starts and runs OK so I don't think that will help, but I can try it. I don't know if the lowish voltage would affect anything or not, but I am not sure what to do about that except replace the alternator. I need to reread some of the comments to see if anything mentioned has not been tried.

Just wanted to give an update with the latest.

Thanks.

 

[alldodge]

Everything is moving like it should, but your voltage not exceeding 13.2 and stays closer to 12.6 needs to be addressed.

 

[QBhoy]

Never rule out that diz cap. All 5 of my cap failures have never stopped it running and starting. I’m aware they can do that, but not with the 5 I’ve replaced in 5 years. One of them was right out the box.
Still leaning towards a power issue somewhere other than that.

 

[lonewolf41]

OK, so here is the latest. I replaced the alternator and now am getting high 13 Volts to low 14 Volts...definitely closer to where I thought it should be. I was hopeful that it might be causing the issue, but alas, it made no difference. I made 3 runs today and attached them to this post. The last one (9-21-19c) is probably the best to look at as I tried to vary the throttle to different values and hold it to get good data. I feel the throttle position sensor is working correctly. In fact, I took a video of me opening the throttle while recording the value seen by the ECM. and you can see the values changing in step with the butterfly as it opens and closes. That video is linked.

I am not sure what else to check or do at this point. Timing is the only thing that I have not really looked at, but I don't see much about it in the manual. If you look at the data in the files, the engine has run up to 4990 RPM at some point. Should I see if I can get it above 4500 RPM with the drive in neutral? I have not done that, but I assume that would not be an issue.

 

[alldodge]

I don't know. Sent the link to the files to another on OSO with hope he can look at it

The MAP is staying above 100, TPS can go up and down but RPM stays up.

Assuming in other post, 14V is high and low is 13V. Going to 13V if accurate, this is still a problem. This is why mentioned it needs to be investigated (measured with good meter).

You may have an ECM issue and something has been reprogramed and the reason for the issue. Right now I don't know, just things don't add up

 

[lonewolf41]

I don't know. Sent the link to the files to another on OSO with hope he can look at it

The MAP is staying above 100, TPS can go up and down but RPM stays up.

Assuming in other post, 14V is high and low is 13V. Going to 13V if accurate, this is still a problem. This is why mentioned it needs to be investigated (measured with good meter).

You may have an ECM issue and something has been reprogramed and the reason for the issue. Right now I don't know, just things don't add up

I may not have been real clear on my description. So the running voltage is now ~13.8 to 14.3 (staying above 14 most of the time) where it used to be 12.8 to 13.3 or so. I am thinking this is adequate. The only time it would dip much is when I would hit the trim. I think the data in the files show this. Maybe I am wrong. I have a craftsman and Amprobe voltmeters that I can use. I have a couple of others, but those are probably the best.

I would definitely welcome any other input on what is going on. There has to be someone who can look at the data and see something. I just don't know who that is and I am starting to doubt whether a volvo shop that can diagnose it as this seems so bizarre.

Thanks again for the help.