1hz won't start - fuel injector pump issue?

[Chazwazza]

I'm working on repairing an 80 series landcruiser with my Dad, but he's out of ideas with this problem. I'm still learning the ropes, so bare with me. Any advice is appreciated.

I recently swapped out my leaking injector pump with one from a wreck that had no previous issues. During this process we've also put in a new primer pump, fuel filter and fuel cut -off solenoid.
I've since been able to start the car on two occasions and have it idling in the driveway for upwards of 15 minutes.
The second time we tried to start the car, it did require some adjustments with the fuel load screw, but still roared to life.

Now we are unable to start the car. We've inspected the injector lines and can see that fuel is not going into them. It looks like fuel enters the pump and the primer pump is getting good pressure, but then it appears that fuel does not leave the pump.

I'm wondering if there is a potential clog or airlock and what else I could try to diagnose and fix the issue?

 

[TheBussman]

first thing to check is the solenoid and circuit. does it click when you turn the key on? is the solenoid getting power when you turn on the key?

 

[mudgudgeon]

Yeah, as above. Check the fuel cut off solenoid is operating. It's on the rear of the injection pump, above where all the injector lines bolt on.

If you pump the fuel primer, does it get firm? Does pumping this get it started?

If you've already had it running, the injector lines and injector pump should be primed.

If you have a small leak in a fuel hose, fuel can drain back to the tank and air gets into fuel lines.
Reusing old, hardened rubber fuel hose is a bad idea. Common for then to leak just enough to cause a problem, but not see any fuel leak.
Air in the fuel lines or injection pump will make it hard to start.

If the fuel cut solenoid is clicking on/off with the key, go back to the fuel screw.
If it was running, and this is the only thing you changed. Try to put it back how it was, see if that helps.

How did you set the timing on the replacement pump?
If you lined up the marks on the pump and engine, this might be close, but not close enough.
The marks are there as a guide for installation only. They aren't accurate enough to get the timing right.
You may need to adjust pump/injection timing by rotating the pump slightly. A small change can make a big difference. Move it literally 1-2mm at a time.
If the replacement pump is timed right you shouldn't really need to change the fuel screw. Maybe adjust idle speed, but that's about it.

Keep asking questions.

Dad's are muppets! Trust me on this I've been one for 22 years

Without joking though, there's heaps of help available here. And if your dad hasn't had much to do with diesels, there is a bit to learn for sure.

 

[Chazwazza]

first thing to check is the solenoid and circuit. does it click when you turn the key on? is the solenoid getting power when you turn on the key?

Yeah I've checked and swapped out three solenoids now, as a bit of a trial and error process, but all them clicked when tested. I had the one off my original pump, the replacement pump and as a last ditch effort I brought a brand new one to try, which is what's currently installed.

 

[Chazwazza]

Yeah, as above. Check the fuel cut off solenoid is operating. It's on the rear of the injection pump, above where all the injector lines bolt on.







If you pump the fuel primer, does it get firm? Does pumping this get it started?







If you've already had it running, the injector lines and injector pump should be primed.







If you have a small leak in a fuel hose, fuel can drain back to the tank and air gets into fuel lines.



Reusing old, hardened rubber fuel hose is a bad idea. Common for then to leak just enough to cause a problem, but not see any fuel leak.



Air in the fuel lines or injection pump will make it hard to start.







If the fuel cut solenoid is clicking on/off with the key, go back to the fuel screw.



If it was running, and this is the only thing you changed. Try to put it back how it was, see if that helps.







How did you set the timing on the replacement pump?



If you lined up the marks on the pump and engine, this might be close, but not close enough.



The marks are there as a guide for installation only. They aren't accurate enough to get the timing right.



You may need to adjust pump/injection timing by rotating the pump slightly. A small change can make a big difference. Move it literally 1-2mm at a time.



If the replacement pump is timed right you shouldn't really need to change the fuel screw. Maybe adjust idle speed, but that's about it.







Keep asking questions.







Dad's are muppets! Trust me on this I've been one for 22 years







Without joking though, there's heaps of help available here. And if your dad hasn't had much to do with diesels, there is a bit to learn for sure.



Hi mate,



I appreciate the lengthy reply! Haha, I gotta appreciate my Dad, he's pulled apart and put back together quite a few cruisers but in the past issues with injector pumps have been referred to a specialist.



My only other experience is working on a 2F petrol engine, so diesel is quite the learning curve!







I have checked the fuel cut off solenoid to make sure it clicks and even put a brand new one to make sure it's not the problem.

Yeah, as above. Check the fuel cut off solenoid is operating. It's on the rear of the injection pump, above where all the injector lines bolt on.

If you pump the fuel primer, does it get firm? Does pumping this get it started?

If you've already had it running, the injector lines and injector pump should be primed.

If you have a small leak in a fuel hose, fuel can drain back to the tank and air gets into fuel lines.
Reusing old, hardened rubber fuel hose is a bad idea. Common for then to leak just enough to cause a problem, but not see any fuel leak.
Air in the fuel lines or injection pump will make it hard to start.

If the fuel cut solenoid is clicking on/off with the key, go back to the fuel screw.
If it was running, and this is the only thing you changed. Try to put it back how it was, see if that helps.

How did you set the timing on the replacement pump?
If you lined up the marks on the pump and engine, this might be close, but not close enough.
The marks are there as a guide for installation only. They aren't accurate enough to get the timing right.
You may need to adjust pump/injection timing by rotating the pump slightly. A small change can make a big difference. Move it literally 1-2mm at a time.
If the replacement pump is timed right you shouldn't really need to change the fuel screw. Maybe adjust idle speed, but that's about it.

Keep asking questions.

Dad's are muppets! Trust me on this I've been one for 22 years

Without joking though, there's heaps of help available here. And if your dad hasn't had much to do with diesels, there is a bit to learn for sure.

Hi mate,
I appreciate the lengthy reply! Haha, I gotta appreciate my Dad, he's pulled apart and put back together quite a few cruisers but in the past issues with injector pumps have been referred to a specialist.
My only other experience is working on a 2F petrol engine, so diesel is quite the learning curve!

I have checked the fuel cut-off solenoid to make sure it clicks and even put a brand new one in to make sure it's not the problem.

The fuel primer does get firm when pumped, and I can feel the pressure building up, but fuel still won't go into the injector lines and the engine won't start up.

Your comment about a small leak in the fuel hose is interesting. I think I'll have to investigate that further. Might be good maintenance to replace some hoses anyway.

I think I'll have to go back and look at the timing again too. As it was running before it might make sense if the pump has shifted slightly....and maybe I was a muppet who didn't tighten it up properly

I won't get a chance to work on the 80 until the weekend, but I appreciate all the advise and will have to report to back

 

[mudgudgeon]

I think I'll have to go back and look at the timing again too. As it was running before it might make sense if the pump has shifted slightly....and maybe I was a muppet who didn't tighten it up properly

The pump shouldn't move.
You might have the timing aaaalllmost right, close enough it started before, but off by enough to not want to start again.

You can tweak it and see what happens. You can always put it back to line up the marks and start over.