GQ Diesel Fuel Issue
Posted: Thu Jan 27, 2011 7:42 pm
Hey guys I have an issue with my GQ 4.2 diesel. It starts, idles and free revs to redline, however under any kind of load it mis-fires blows a f*&% load of white smoke and carries on like a retard.
I have tried everything short of replacing the injector pump, the lift pump works fine, the pick up in the tank is not blocked, the fuel lines have no leaks so it's not sucking air anywhere, I have made it mis-fire badly and stopped the car immediately to check if the glass fuel bowl is empty, which it wasn't so the lift pump is working fine and supplying the IP with enough fuel, none of the injectors leak, I've bled the fuel system countless times to no avail.
The conclusion I have come to is the IP's internal fuel pump cannot keep up with the fuel delivery under load, is this plausible? Has anyone had this drama before? I'm getting sick of it sitting in my yard doing nothing, I cant even go out for a wheel as it won't do any speed above about 40Km/h without pouring a gut full of white smoke out the back which is definitely unburnt fuel as it smells like kerosine.
Another thought I've had is maybe one or two of my injectors may be a little blocked and is not spraying the fuel into the cylinder, dribbling it in instead which is making it not burn.
Another thing I want to also try is putting a high volume low pressure electronic lift pump in between the mechanical lift pump (the top of the fuel filter) and the IP. Where might I find one of these?
This has happened since I put some shitty fuel in which had some water in it, there wasn't much water in the bowl, but none the less there was still water there. Coincidence or not?
it used to do something similar around corners like it was starving for fuel when the body leaned right over, however it would clear up virtually straight away. Now it does it in a straight line VERY FRUSTRATING.
Any help would be greatly appreciated.
Cheers,
Glenn.
I have tried everything short of replacing the injector pump, the lift pump works fine, the pick up in the tank is not blocked, the fuel lines have no leaks so it's not sucking air anywhere, I have made it mis-fire badly and stopped the car immediately to check if the glass fuel bowl is empty, which it wasn't so the lift pump is working fine and supplying the IP with enough fuel, none of the injectors leak, I've bled the fuel system countless times to no avail.
The conclusion I have come to is the IP's internal fuel pump cannot keep up with the fuel delivery under load, is this plausible? Has anyone had this drama before? I'm getting sick of it sitting in my yard doing nothing, I cant even go out for a wheel as it won't do any speed above about 40Km/h without pouring a gut full of white smoke out the back which is definitely unburnt fuel as it smells like kerosine.
Another thought I've had is maybe one or two of my injectors may be a little blocked and is not spraying the fuel into the cylinder, dribbling it in instead which is making it not burn.
Another thing I want to also try is putting a high volume low pressure electronic lift pump in between the mechanical lift pump (the top of the fuel filter) and the IP. Where might I find one of these?
This has happened since I put some shitty fuel in which had some water in it, there wasn't much water in the bowl, but none the less there was still water there. Coincidence or not?
it used to do something similar around corners like it was starving for fuel when the body leaned right over, however it would clear up virtually straight away. Now it does it in a straight line VERY FRUSTRATING.
Any help would be greatly appreciated.
Cheers,
Glenn.