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GQ Diesel Fuel Issue

Posted: Thu Jan 27, 2011 7:42 pm
by thelux
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.

Re: GQ Diesel Fuel Issue

Posted: Fri Jan 28, 2011 4:44 pm
by thelux
Anyone??

Re: GQ Diesel Fuel Issue

Posted: Fri Jan 28, 2011 6:21 pm
by nissannewby
could be pump timing

Re: GQ Diesel Fuel Issue

Posted: Fri Jan 28, 2011 7:14 pm
by thelux
The pump timing has never been touched, and it starts and free revs way to easy for the pump timing to be out.

Re: GQ Diesel Fuel Issue

Posted: Fri Jan 28, 2011 9:52 pm
by REV_310
maybe it caught wind i just turbo'd mine. now it has its tail between its legs. its getting plenty fuel has to be ip

Re: GQ Diesel Fuel Issue

Posted: Fri Jan 28, 2011 9:59 pm
by thelux
REV_310 wrote:maybe it caught wind i just turbo'd mine. now it has its tail between its legs. its getting plenty fuel has to be ip
Go away with your shitty series one! Come back to me when you have the spectacular options mine has.

Re: GQ Diesel Fuel Issue

Posted: Sun Jan 30, 2011 8:46 am
by GaryP
I had a similar problem when I changed over to a CAV fuel filter, you wont see any air in the glass bowl all you will see there is any water. The only way to tell if you have an air leak in the system is to turn the filter upside down and the air bubbles will be pretty obvious. Using the primer built in will only get some of the air out I had to invert the filter and pump the last of the air out of the drain valve at the bottom.

Re: GQ Diesel Fuel Issue

Posted: Sun Jan 30, 2011 9:51 am
by GutSquisher Media
Your not going to like this, it sounds as your injector pump is stuffed.

White smoke is the result of the fuel not having enough heat to burn, this is the cause either due to the motor been way way down on compression (but if this was the case you would have would find the motor hard to start and it would blow white smoke at idle as well). The other is the pump is flooding the chamber with that much fuel it is cooling the combustion chamber.

Either way sounds like a trip to the diesel mech is on the cards for you.

P.S I would recomend puting a electric pump in any TD42 that has work done that has increased power output. I use a Carter Rotary vane design pump which delivers a max 7 psi.

Re: GQ Diesel Fuel Issue

Posted: Sun Jan 30, 2011 5:46 pm
by REV_310
FIXED!!! pissed the glass bowl type filter one off for oem one