I have a Volvo Penta 96 7.4L Gi EFI engine. At idle to 1500 RPM's the engine stumbles and then goes back to normal operation. Sometimes it will die, but I am able to restart with no problem. At cruise or wot I have no problem. Engine produces full power and runs smooth. Problem occurs after engine is warmed up.
I bought the boat last year and had to replace the fuel injectors, because the four rear ones were rusting badly and one had cracked and was leaking. I bought after market fuel injectors ( all 8) that were matched to the oem fuel injectors for half the price.
I have replaced the fuel filter. Checked fuel pressures, replaced the sparkplug wires, distrubor cap and rotor. Engine always starts right up and runs smooth. Again only between 800 (idle) and 1500 rpms does it stumble when it's warmed up in or out of gear. I also have a fuel flow gauge installed and when it stumbles the fuel pumps whine and fuel flow increases to about 25gph then right back down to normal.
This has been driving me nuts for a year now. Any ideas would be a great help. Seems like it's a fuel problem but I'm not sure what to do next.
Thanks for any help.
Jim
I bought the boat last year and had to replace the fuel injectors, because the four rear ones were rusting badly and one had cracked and was leaking. I bought after market fuel injectors ( all 8) that were matched to the oem fuel injectors for half the price.
I have replaced the fuel filter. Checked fuel pressures, replaced the sparkplug wires, distrubor cap and rotor. Engine always starts right up and runs smooth. Again only between 800 (idle) and 1500 rpms does it stumble when it's warmed up in or out of gear. I also have a fuel flow gauge installed and when it stumbles the fuel pumps whine and fuel flow increases to about 25gph then right back down to normal.
This has been driving me nuts for a year now. Any ideas would be a great help. Seems like it's a fuel problem but I'm not sure what to do next.
Thanks for any help.
Jim