2H fuel problem (1 Viewer)

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Sweden
Hi guys!
First thread for me on this absolutely fantastic forum :) Have found a lot of answers to questions here but this time i have to ask. I have a 1988 HJ60 with a 2H, manual, here in Sweden. Runs great and i love it. But, it has an issue that i dont love so much - the reason for my question - When driving slow, 40-50 km/h in 4th gear, around 1400-1500 rpm on a level road (light load) just cruising along the engine starts to oscillate (right word?) It starts gently and increases fast. It is like moving the accelerator pedal up and down fast and it gets worse by itself. If i press the accelerator pedal down more or let it up i stops but comes back when return to just trying to maintain speed. Will not happen on slightly higer rpm or under more load. It feels like something that delivers fuel is moving back and forth by itself. The engine is serviced, new filters. New vacuum hoses from the intake to injection pump, no leaks. There is no lack of power, it revs fine. What do you guys think?
Have a great day!
 
Its not a typical symptom of a broken leather diaphragm in the injection pump.. but I think I'd be going ahead and changing it at this point. I'd also change the fuel filter if you dont know when it was last done.. and I'd consider pre-emptively bypassing the sedimenter.

Do one thing at a time though.
 
You could be lugging the engine at those RPM's, does it feel like you're been bounced around back & forth?
Welcome to IH8mud!
 
Thank you for your answers! Since i am swedish - what means with lugging the engine? Rpm's too low? But yes, it feels like that. Engine is "on and off" when this happens. Have looked at detailed pictures of the pumps internals trying to understand what can cause something like this. Is it not the diaphragm that controls something witch manages the fuel? I am thinking it is either a vacuum problem fooling the pump that i am being stupid with the accelerator pedal or there is an internal problem inside the pump.
 
If the engine really is going OFF and ON and not gently surging up and down then its just the classic EDIC cycling issue.. pull the EDIC rod off and go for a drive.. your first description was not as descriptive as your subsequent post in this regard.

This is a common problem with 2Hs. The EDIC may be cycling to STOP briefly. Its usually poor engine or body earths and it usually happens more when there's a heavier electrical load on the alternator (eg headlights on). To fix it remake all your earth points (new terminals, wirewheel on the attachment points, new cables if necessary).. mostly this solves the problem. In the meantime you can pop the EDIC rod off and it'll stop the problem, but you'll have to stall the vehicle to stop it.

The EDIC rod is shown below, it pops off at both ends.

1596144282848.png
 
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Thank you! Will try removing the EDIC and go for a drive. I find it a bit difficult to explain this in a good way, also in a different language o_O I am really happy for the help!
 
I had the same issues with a HJ47, cleaning the grounds sorted it as it was the EDIC acting up
 
If it's the electrical contacts of the EDIC system, would it be acting up at all times and not just at a specific rpm? I've never encountered the EDIC symptoms mentioned and I could be way off base :rolleyes: Another test to do is rev the engine at 1500RPM in neutral and observe!
 
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Thanks again for your replies!
EDIC is not responsible in this case. It is completely still, electrical connections are ok. I tried removing the arm and to, no difference. I'm ordering a new diaphragm from Toyota, replace it and see what happens. Will let you know the result!
 
Check the state of the two hoses that come down from the throttle body to the injection pump, make sure they're in good order as well. I'd also consider bypassing the sedimenter as a test prior to changing the diaphragm.
 

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