Volvo Penta GXi-E Low Power and 2 DTCs

[alldodge]

Edit: delete this, wrong thread

 

[swalker80020]

Clocking the HVS (not hsv) can be done in a couple ways.

Perfect thank you! Apparently I'm unable to call it correctly. I will refer to it as the flux capacitor from now on.

 

[tpenfield]

Have you been able to get rid of the "41" codes for good? As stated, I'd start there and work your way forward.

 

[QBhoy]

Hi. Despite the ecu controlling the timing on these. You can defo make a fine adjustment to the running of the boat by a tiny tiny movement of the cap either way. I managed to get a boat back to the dock this way, one time it had water in the fuel. Was running lean and popping. Turned the cap a tiny amount to overcome. Otherwise I was towing it with my boat all the way.

 

[Tail_Gunner]

Mecruiser 5.0L MPI distibutor proper clocking?

5.0L MPI Engine Serial OM618927. read a service bulletin on my issue of a miss fire at higher loads. It also stated to rotate the distibutor 1-2degrees if the issue persisted. I did this and the problem got so bad that at about 2500 RPM it misses so bad it sounds like the ECU is reducing...

forums.iboats.com

 

[swalker80020]

Have you been able to get rid of the "41" codes for good? As stated, I'd start there and work your way forward.

Hey tpenfield et al! So after a long winter I finally got the boat back in the water. I went through the diagnostic procedure for clearing the DTC 41 codes with a test lamp this time and sure enough what was reading 12 volts with DMM did not light the test lamp which lead to "replace ICM" (thank you wrench 3). I had already replaced this with an aftermarket, but this time I spent the extra $ and bought OEM. The codes went away! Unfortunately, the power problem did not. In fact, the boat started fluctuating RPMs/power under load like it did when I first started troubleshooting and it is still slow to get up on plane (and impossible with more than 6 people on boat). I recorded the readings while this was happening at WOT and calm lake (see attached). Does anyone know what the manifold absolute pressure should be at WOT?

 

[swalker80020]

Hi. Despite the ecu controlling the timing on these. You can defo make a fine adjustment to the running of the boat by a tiny tiny movement of the cap either way. I managed to get a boat back to the dock this way, one time it had water in the fuel. Was running lean and popping. Turned the cap a tiny amount to overcome. Otherwise I was towing it with my boat all the way.

Hey QBhoy, I did try moving the distributor 1/8-1/4" clockwise and counter clockwise which did not seem to make things better, in fact they seemed a little worse, but hard to say exactly. I did record scan tool readings for both directions which I can send if you think it would be helpful.

 

[ripjmk]

My MAP voltage at WOT is 4.5V. Have you cleaned the spark arrestor lately?

 

[ripjmk]

Correct my last (misread my own notes) MY Voltage at WOT is 4.1V

 

[swalker80020]

My MAP voltage at WOT is 4.5V. Have you cleaned the spark arrestor lately?

I haven’t looked at the exhaust at all but good idea. I will check it out, thanks!

 

[swalker80020]

My MAP voltage at WOT is 4.5V. Have you cleaned the spark arrestor lately?

Ah, you are talking about the intake. Yes, I have cleaned the intake spark arrestor (multiple times), but you do have me looking into the exhaust now. I am going to see if the flapper (which apparently isn't needed) might be causing the problem.

 

[ripjmk]

I think you will find that the flappers were never installed in the 5.0 GXi-E.

 

[ripjmk]

What is your MAP voltage with key on engine off? I just checked mine and it is 4.12 Volts.

 

[swalker80020]

I think you will find that the flappers were never installed in the 5.0 GXi-E.

You are probably right as the flapper parts are not listed in the exhaust diagram for the gxi-e.

 

[swalker80020]

What is your MAP voltage with key on engine off? I just checked mine and it is 4.12 Volts.

I didn't make any recordings with engine off. I will have to check when get up to the boat again. I was curious what the pressure readings of the manifold should be at WOT because my recording is showing readings close to atmospheric. Wondering if there supposed to be high vacuum at WOT

 

[ripjmk]

I looked at your recording and it showed a barometric pressure of 25.0 in hg.
Where are you? To get that pressure you'd need to be at 5,000 Ft.! If you are not I'd look at the MAP sensor.

 

[swalker80020]

I looked at your recording and it showed a barometric pressure of 25.0 in hg.
Where are you? To get that pressure you'd need to be at 5,000 Ft.! If you are not I'd look at the MAP sensor.

Yep, I live in Colorado. This was recorded at Horsetooth Reservoir at 5,430'

 

[ripjmk]

You might be chasing the unobtainable (without a super charger or turbo)
25 / 30 =.83 this is the reduction in air mole weight and also available power as the ECU reduces fuel to match air !

 

[swalker80020]

Finally got boat working well! Replaced cap and rotor AGAIN and now jumps up to plane with 10 people in the boat (and at altitude too, btw). This was the first thing I replaced (with OEM) when problems started a little over a year ago. Must've had multiple issues when I first replaced, but went bad by the time I fixed other issue(s). Guessing either ICM (which eliminated DTCs after I replaced) and/or fuel injectors (two of which tested bad before they were cleaned). Can't believe a brand new OEM cap and rotor only lasted a year! Thank you all for your help and expert advice...I learned a lot!

 

[ripjmk]

Thank you for closing the thread, it's always good to find out what the fix to the problem was.