Harrop 2300 supercharger to Optimiser 6500

[PeeBee]

Struggling with an on-going issue. I came home on the end of a tow rope maybe 4 weeks ago. The car lost power, would not rev over 1400rpm under load and would rev to 3000 then die. I thought it was dirty fuel o faulty lift pump so changed both. Problem persisted so let me to believe one of the fuel computer flow meters has died so took these out of the circuit. Thought problem was sorted then today it died within 3 minutes, initially low fuel pressure the restarted it and back to 11psi. I have wired a direct jumper cable from battery to the injector pump soledoid, and it is a solid flick, indicating fuel has a pathway to the motor. Glow plugs are fully functional. I am going to bypass everything from the outlet of the lift pump to the downstream side of the fuel heat exchanger. How can I test the solenoid is chattering or failing ? Bit at a loss
I guess I should drop the fuel as a test but it looked pretty good when I pumped it thru

[mudski]

Could you run a temporary test light as such, to the solenoid and run the vehicle. If theres intermittent power to the solenoid the light should go off an on aswell. Dunno. my knowledge is very limited on this stuff.

[PeeBee]

Could you run a temporary test light as such, to the solenoid and run the vehicle. If theres intermittent power to the solenoid the light should go off an on aswell. Dunno. my knowledge is very limited on this stuff.

Good idea Mark, I was going to simply listen to the solenoid and see if its dropping out, however unsure how I would get a signal as the power is direct off the battery, so it wont be dropping out but the solenoid may be failing or chattering - I need some help on this. Is there a filter or strainer on the factory fuel tank level device? I am also probably going to put some compressed air down the line from the lift pump back to the tank - lid off the tank, and see if tat improves the scenario. All just takes time and I am fed up with this issue to be frank. Car was running like a bird, then it started to stutter.

[PeeBee]

I an also considering the sitation where I have been chilling the fuel too low with the interchiller loop and resulting in fuel gelling, which would intermittently or gradually clog the filter - perhaps? The current setup has the fuel sitting anywhere from 2-8degC normally around 12 degC. This is the temp coming back from the tank, as it takes a bit to drop the whole system down, so its conceivable the fuel temp in the heat exchanger is getting well below that - its a hypothesis I guess????

Anyway, I run a very expensive winter additive, and reached for the new can this arvo to dose the tank - only to find the un-opened can was 60% full - thats not great value. Anyway, reached out to the supplier, who I have bought a lot of gear from, and surprised, but whole new can on the way, no qualms - great customer service.

[mudski]

Can you raise the temps for the fuel? Or shut it off completely to test run it so the fuel is at ambient temp? Your theory does sound plausible...

[PeeBee]

I dosed the tank up with a deep cold brew additive. I then ran the car at 1000, 1500, 2500 and finally 3000rpm for maybe 30 minutes. The engine was stuttering and hunting all over the place from 1000, surging to 1800, running very rough. By the end, the fuel temp was at 40 degC and radiator at 93degC. I brought it back to idle and its ticking along like a watch, so from now the fuel cooler only gets used when fuel is above 40 degC and then with moderation to a limit of say 30degC, as I am sure I pushed the limit too far. Will run it again tomorrow and gauge the result.

[mudski]

Im wondering if cooling the fuel affects the injector performance as the fuel surface tension/ thickness/ runnyness is not going to be, normal?

[PeeBee]

Im wondering if cooling the fuel affects the injector performance as the fuel surface tension/ thickness/ runnyness is not going to be, normal?

Cooling the fuel to around zero allows the formation of wax within the fuel. The viscosity no doubt does change, however the symptoms suggest the filter pre the lift pump was plugged as I was getting reduced pump pressure - instead of 10psi I saw 5 then down to zero, like the pump had failed. When I disconnected the fuel hose from the discharge of the pump, at home, with a long fuel hose, open ended the flow was there, however no pressure, fuel sort of pumped out very slowly, instead of at a gushing rate when the fuel normally would shoot 3-4m out of the hose, it was like 5cm at best.
Also, if the fuel was thicker and there was no blinding of the filter, the fuel pressure would rise as its density has increased. The Carter Blacks are rated to 15psi I believe, however they can only produce pressure as to what the system resistance is. Now, funny enough, and this might seem an opposite argument, once I had run the viscosity improver - cold weather ant gel liquid, the system pressure rose to 11.5psi, normally flatlines at 10psi. I put this down to the pump being able to pump more diesel to the injector pump and the increase in vol/vel generates the higher system resistance or pressure.
So, I think the plug formation was forming inside the fuel lines as well, however from yesterdays trial, appears to have now been resolved.
I dont know about injector performance however the Standyne pump is a bit different configuration to most - there is an internal reservoir inside the pump where the injector feed pistons feed from. Any fuel above the nominal feedline is simply pushed out of the pump to return to tank. I guess is the diesel is thicker it wont flow as readily into the piston cavity, hence there could be cavitation occurring or 'short filling' taking place, which might also partially explain why the engine was running so poorly. Once its into the charge piston, I guess it would affect the spray pattern out the nozzles as well, but being a direct displacement, it would have to be pushed out - higher internal pump pressures I guess. Bit of speculation here, but you can follow the process. If the overall reservoir was lower or barely matching demand there could be a cavitation scenario taking place also.

[PeeBee]

Fired the truck up this arvo, runs sweet! Reckon this was the issue all along, fuel gelling - another piece of the puzzle

[BrazilianY60]

This deserves an youtube video of the beast chugging down the road like a road-train. In-cab. No instrument readings. Just the GQ bonnet, the road and the sound!