Saturday, Mar 12, 2016 at 17:28
With reference to what Bob has posted, I guess it depends on what year Troopy we are talking about.
My 1991 HZJ75 (ute but same fuel system) has the 1HZ diesel. I am pretty sure the first year Toyota went to that engine as a replacement for the 2H in the 70 series. It has the standard factory long range tank with 4 total solinoids. 2 inlet and 2 return. Also the extra gauge and push button selector switch in a binacle (pod) in the center top of the dash. I have owned a couple of earlier 70 series diesels but none had the extra tank so no switches or solinoids.
I guess if the earlier models only had 1 solinoid the return fuel volume wasn't enough to make much difference. The 2H engines had an in line fuel pump and from memory the only fuel returning from the engine was from the injector bypass lines. Maybe some from the fuel pump but I can't remember.A very small quantity unless one or more injectors were absolutely stuffed. Once again from memory, the fuel from the bypass line was actually fed back into the inlet side of the standard fuel filter so no return to tank required even if the standard Toyota long range tank was fitted.
With the rotary (VE) style fuel pump which had just 1 high pressure plunger element and an integral transfer pump as used on the later 1HZ and the turbo engines they probably needed to circulate a much higher volume of fuel for lubricating and cooling. Hence the necessity to return fuel to the same tank as is being drawn from.
A far as the extra switch and gauges mounted under the
seat????? No idea, but maybe as Bob suggested more to do with adjusting air pressures for some after market
suspension?????
Cheers
Pop
FollowupID:
866322