VP 5.7 gxi E 2003 problems

[GPC]

I have a FW with twin 5.7 GXi-E 2003. We are experiencing the following: when port engine goes over 3,000 rpm suddendly looses power.
Already scanned the ECU: no errors/faults.
Run some test recording the engine parameters under load at certain RPM (3,300 approx) recording the engine parameters before the inconvenience and after.
Engine runs OK with a spark advance of 32.6 deg. When the problem happens the spark advance goes decreases to 28 deg.
Injector Pulse width goes from 6.0 ms to 7.9 ms.
The result is an evident loss of power.
Any help with troubleshooting is welcome!
Thanks in advance
GP

 

[GPC]

Re: VP 5.7 gxi E 2003 problems

Looks like the spark advance is changing the loss of power.
The problem now is to know what sensors/signals are used by the ECU to set the spark advance.
Anyone could help me with this info?
Thanks in advance
GP

 

[rschap1]

Re: VP 5.7 gxi E 2003 problems

I wonder if the controls are seeing a lean condition?
Retarding the timing and leaving injectors open longer...
Possible causes that come to mind are fuel pressure dropping-clogged filter, poor pump maybe.
or water/condesation in the fuel creating the readings telling control that you are running lean.

 

[GPC]

Re: VP 5.7 gxi E 2003 problems

Thank You for the suggestion - I will check.
There is a parameter recorded called Fuel Pressure Volts and Fuel temperature Volts: does anyone knows what they should be at?
Thank You
GP

 

[muc]

Re: VP 5.7 gxi E 2003 problems

might want to check fuel pressure @ 3000 rpm under load.

 

[GPC]

Re: VP 5.7 gxi E 2003 problems

I made a check on the fuel pressure. Boat was stationary - no under load.
Fuel pressure at idle was oscillating between 50-70 psi (specs said 50-60 psi).
Same behavior at any engine speed between 500 - 3,500 rpm.
Pump, regulator or bot?
Any suggestion appreciated

PS :Repeated the same measurement on the other engine: dead on 50 psi - no movement.

 

[dypcdiver]

Re: VP 5.7 gxi E 2003 problems

Quick and simple test would be to swap the fuel pressure regulators and test again.

 

[muc]

Re: VP 5.7 gxi E 2003 problems

Sounds like you might be getting air in the system maybe due to a fuel restriction.

Maybe try this?

http://forums.iboats.com/showthread.php?t=283269