2.5 Na diesel high RPM

Hello all, I have an 89 127 with a 2.5 na diesel. I can start it just fine and drive it around for a little bit but once it heats up the engine starts to rev at high rpm’s very sporadically.

You can get it to go back down to normal if you cover the intake for half a second but then the Rpm’s will take off again.

Anyone have any clue on what problem I have here? Thanks in advance

Justin

Throttle cable free play?

Is it eating it's own oil through the breather system? Does it have heaps of blowby from being worn out?

- if it's runs away, it can destroy itself! If it's running on it's own oil, none of the speed control mechanisms apply and it will just rev to whatever it can get too, which may be well past the governor speed.

lynall said:

Throttle cable free play?

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Hey thanks for reply. No, throttle cable is new and it happens even if you just let it sit and run awhile.

AllanWorms said:

Is it eating it's own oil through the breather system? Does it have heaps of blowby from being worn out?

- if it's runs away, it can destroy itself! If it's running on it's own oil, none of the speed control mechanisms apply and it will just rev to whatever it can get too, which may be well past the governor speed.

Click to expand...

It’s not running away. It will just rev up to a certain point then it’ll come back down. It continues and gets worse the longer you run it. When I turn the ignition off, it runs for a few more seconds then cuts off.