1Hz 4.2 not building prime... sending fuel back down return line (1 Viewer)

[KwaTeebs]

Hi Guys...

I had a fuel issue on my cruiser... I had just completed a 4000km road trip... and then another 1100km road trip on the vehicle with no issues when 7 days later it was struggling to start, and eventually would start only after hand priming or push starting on a hill. This proceeded to get worse over 48hours and eventually would not even hold idle.

Things I have done:
- I found an air leak on the fuel line by the tank & repaired that.
- I replaced the fuel cutoff solenoid a there was a small fuel leak out the top of the old IP solenoid where the power connects. I replaced the solenoid
- Ran an inline hand pump to rule out that fuel filter was not an issue

This did not solve the problem, and it felt like something was wrong with the Injection Pump, as we couldnt find any other air leaks. Pulled the pump and sent it to a shop to be inspected. The shop said the pump was all fine perfect except for a damaged O ring on the solenoid from when I tried to install it while on the vehicle

Anyway today we put the serviced Injection Pump back in, and it will not build prime on the on the fuel filter pump. When I pumped I could hear gurgling on the fuel tank...

I discovered that if I manually block the fuel return line, the pump builds up pressure fine... but if I dont block it, its sending the fuel down the return line instead of building pressure! We pulled the glow plugs and ran the starter a few times, and also cracked some of the injectors... it feels like no fuel is getting to the injectors, and it is all going down the return line. It was a brand new solenoid from Toyota, so I dont think it is the problem, plus the shop did test it I believe.

Am I missing something?

 

[mudgudgeon]

Air in the system.

Try installing a piece of clear pvc hose between fuel filter assembly and fuel pump. A $10 and 10 minutes to swap in a piece of clear hose can save a lot of guessing.

Any air bubbles means you're getting air into the system.

Typical causes have been covered here hundreds of times.

 

[iik00]

Any updates on this one? I'm experiencing something similar.

 

[roscoFJ73]

I discovered that if I manually block the fuel return line, the pump builds up pressure fine...

I'm wondering if it was a pump problem, somehow the fuel is leaking past a valve or something and running back into the fuel return. But do the cheap things first.

 

[KwaTeebs]

Any updates on this one? I'm experiencing something similar.

As per @roscoFJ73 I would start with the simple things first... I had a few air leak issues actually.

The main hidden one was a leak on the fuel tank pickup~ that it was sucking air from a hole in the pickup inside the fuel tank! I dropped the tank and got this welded closed

But I ended up removing the fuel pump to get it checked out. There was nothing wrong with the fuel pump. We reinstalled it, and I got the guy who serviced the IP to give it a once over and he measured the ?distances?. Car started no problems after that, but there was a periodic terrible whining / screaming sound. This settled down after a few days.

The car was actually driving quite well, then one drive about an hour away from my house it just cut out. Managed to get her started again, but there was so much white smoke out the back and I could not get her to idle at all. This was my first breakdown in the entire time of owning the vehicle that I had to get her towed and I could not fix the issue on the side of the road.

I could not figure it out, so took it to a local cruiser mechanic, and he is still trying to figure out where the issue sits. We did test bypassing the fuel tank, then using a hand pump and bypassing the fuel filter... all with the same white smoke and no ability to idle issue. So the engine is turning, and it feels like a problem with the fuel supply.

I fear that whining noise was something that went wrong in the reinstallation of the fuel pump. Still figuring it all out, and she is not driveable right now.

Have you made any progress on your vehicle?

 

[KwaTeebs]

update on my side... I think my initial problem was related to the air leak on the feeder line inside the fuel tank... not sure tbh

Then the second problem was unrelated. It turned out that when I reinstalled the Injection Pump we didnt torque the main bolt properly, and it came loose in the sheath and thats what caused my timing issues and the inability to idle. Shoddy labour on my side