1992 200tdi 90 High Reving Engine on Start Up🤔

Hello
On the search for some suggestions please.
So, progress to date & current challenge.

Engine starts up ok (Sounds Strong) but immediately goes to high revs and I have to shut engine off.

I have drained fuel from tank, cleaned lines, replaced glow plugs, new fuel lift pump, replaced fuel filter.

Sounds like choke is stuck open or could it be injectors ?

Appreciate any information

Mepps said:

Hello
On the search for some suggestions please.
So, progress to date & current challenge.

Engine starts up ok (Sounds Strong) but immediately goes to high revs and I have to shut engine off.

I have drained fuel from tank, cleaned lines, replaced glow plugs, new fuel lift pump, replaced fuel filter.

Sounds like choke is stuck open or could it be injectors ?

Appreciate any information

Click to expand...

Assuming you have wound the accelerator cable all the way off.

Hello, yes, disconnected accelerator cable . Thanks, I should have mentioned on post .

Mepps said:

Hello, yes, disconnected accelerator cable . Thanks, I should have mentioned on post .

Click to expand...

Seized boost pin perhaps, remove the 4 screws on the top plate on the injection pump & remove the boost pin.
Clean & re-fit. Vids on youtube mind an mark/take note on the positioning on the pin.

Sounds interesting, I will definitely try your suggestion re: boost pins
If successful, I will let you know.
Many thanks

I assume it was running normally before and hasn’t always been like this with you?
It does sound like the fuel rack is sticking so definitely worth trying the above.

But this might be an odd suggestion here and only really applicable if someone has been messing with the pump. But could try adjusting the idle screw? If that has been wound all the way in by someone playing with the pump not knowing what they are doing it could do this.

Hello,
I only took ownership of vehicle in March this year.
My First Defender ...
Engine was not running as parts missing. Probably 10 years or so off the road.
It's a low mileage jeep and mechanic did look after when it was in use as I was familiar with jeep before it moved to me.
I did check idle screw & will check again. If I have any success, I will share.
Either way, I am enjoying the process and learning as I go.
Thanks for your help

kevstar said:

Seized boost pin perhaps, remove the 4 screws on the top plate on the injection pump & remove the boost pin.
Clean & re-fit. Vids on youtube mind an mark/take note on the positioning on the pin.

Click to expand...

Hello Kevstar
Your diagnosis was correct & thank you.
Much appreciated
Attached photo , don't laugh, ha ha
All cleaned now & engine is idling & reving nicely.

I replaced clutch cylinders and pipes etc and now after testing, we have a clutch.

Next up is drive shaft & rear diff to be repaired / fitted. Lots to do, making good progress.

Hello,
High Reving on start up is now resolved.
Stuck / Seized boost pin was the issue.
Removed/ cleaned/ lobricated etc .
Seems to have worked. Engine sounding great.
Thank you all for suggestions & your help.
Great Forum

Mepps said:

Hello Kevstar
Your diagnosis was correct & thank you.
Much appreciated
Attached photo , don't laugh, ha ha
All cleaned now & engine is idling & reving nicely.

I replaced clutch cylinders and pipes etc and now after testing, we have a clutch.

Next up is drive shaft & rear diff to be repaired / fitted. Lots to do, making good progress.

Click to expand...

Superb, glad you got it sorted well done mate.