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Goanna
01-27-2019, 01:14
Hi guys
New here and hoping for some thoughts and solutions.
My 6.5 has been running as a mechanical motor for ten years.
12 months ago it had a electrical fire in the engine bay and the motor was dusted with a powder fire extinguisher. It was rebuilt and running well with 2500 kilometers on the new motor when the oil cooler line split and cooked the crank. A strip down, regrind of the crank and line bore of the block were required. The engine was reassembled and fitted. After bleeding the fuel system an attempt to start was made. The engine fired and reved to about 3500 rpm and shut down. The fuel supply and return lines have all been cleared and air removed. The engine continues to start run to a high idle of around 3500 rpm and shuts down.
Any thoughts or help would be appreciated rembering that I am using a mechanical injection pump. If it was an electrical pump with a pmd I would look there.
This is my work vehicle and I am struggling with it off the road so all help ans suggestions will be looked at and checked. It was running so well befor the oil line split so I am at a loss.

Robyn
01-27-2019, 07:21
Hi

This scenario acts like an air in fuel issue.

Does the truck still have the electric fuel lift pump ?????

If so the pump needs to be running to prime the system and then be powered any time the engine is running.

The lift pump must produce about 4 psi and a good flow to the filter/injection pump.

Let us know

Yukon6.2
01-27-2019, 10:38
Hi Goanna

Was there any work done on the injection pump when the engine was rebuilt?

Goanna
01-27-2019, 17:02
Hi
Yes it is running an electric fuel pump with a constant 6 psi at the pump. There dosen't appear to be any air in the system. My main concern is that the engine starts and immediately goes to hi idle without any acceleration. There has been no work on the injection pump and it was running well before the oil line split and cooked the crank.
Again thanks for you thoughts

Goanna
01-27-2019, 17:12
Hi
My concern is if the governor inside the pump could be sticking as it was working before the engine was repaired. The fuel system has a lift pump to a surge tank 2lt capacity which is a 16psi hiflow pump with return to tank and holds 4psi. The engine is feed by a pump off the surge tank with a 10psi pump regulated to 6 psi and has pressure gauges on both sides of the system. My last 6.5 ran the same system for 10 years without problem and was running 6 to 9 psi on a variable regulator regulated by boost pressure. The regulator on this motor is a constant 6psi. I am showing a reasonable flow from the injection pump return.
Again thanks for you thoughts

Goanna
01-28-2019, 07:43
For some reason the governor was sticky holding full fuel then flicking to no fuel and sticking again. I have not found a reason for it to stick but now seems to be working and holding idle. Runs well to about 2500 rpm and then starts to miss. It also seems to be over fueling as it is blowing lots of black smoke and puffs white then black until warm then just runs black smoke.

Robyn
01-28-2019, 09:48
This has got to be an injector pump issue for the sticky governor.

The missing and black smoke are another call.

Turbo working ????
A stuck open waste gate will make it smoke like a coal chimney..
A plugged air filter ???

The miss is a question though.

Timing ???
Possible bad injector or is related to the IP itself.

When was the IP last in the shop and checked/rebuilt