2004 8.1 GI has no throttle response above 2600rpms under load
I was running well at 3800rpms the other day and the motor just started to loose power. It now will not go over 2600rpms under load. It is acting like it is fuel starved. So far I have eliminated all tank and line issues by running brand new gas straight from a portable tank to the fuel pump. I changed the filter and checked the contents and it was clean. Having eliminated most other things I replaced the pump and the symptoms are the same.
Both pumps were reading 37-40 lbs on the high pressure side. The only spec I could find was for the 5.7GI which appears to use the same pump, and it specifies 50 to 60 lbs which is why I thought the pump was bad.
Oil pressure and temperature are normal, and it does not seem to be running rough before it hits 2400 to 2600rpms. At that point there is no additional throttle response.
At this point I am not sure what to do. I don't have a code reader to see if there are issues with the EFI. Does anyone know what the pressure spec should be? Are the LED readers such as the codeMate advertised for volvo engines useful in trying to diagnose this?
Any help in diagnosing this would be helpful.
Re: 2004 8.1 GI has no throttle response above 2600rpms under load
Thanks for the reply.
The symptoms were a bit different in that the high pressure fuel reading does not drop under load. It stays at 40 psi. I did pull the original pump apart, and while there was some pitting on the inner jacket, the pump screens were clean. I wire brushed the inner and outer water jacket walls as much as possible, painted it being careful not to get any paint in the fuel cell itself, and put it back together. This would not have been an enduring repair, but at this point it does not matter since I put a new fuel cell on it.
I still am not sure if that is the correct pressure. I even checked with a volvo dealer. He had the repair manuals for both the 5.7 and the 8.1, and the pressure specs were listed in the 5.7 manual, but the 8.1 manual was missing the tune up specifications completely.
At this point I think the next logical thing to do is to see if there are any error codes set in the ECM.
Would the "CodeMate" reader with just an led be sufficient for diagnosis?
If not, can anyone recommend someone in central NJ that can run an analysis on the engine?