Thread: 3.5 v8 from a disco in my rangie. revs high then stops

I've just put a disco 3.5 v8 in my rrc. It starts but revs to 4-5000 rpm by its self then sits there for 3 or so seconds then shuts off. It will rev higher but still wont run any longer

any ideas on why this might happen ???

Originally Posted by Zacs

it helped it alittle bit but didn't fix. There seems to be a blockage somewhere in the fuel rail i think. Its building alot of pressure. To the point its leaking where the pressure reg joins the rail

The only blockage in the fuel rail will be the fuel pressure regulator itself. With the fuel pump energised there should be fuel flowing out of the regulator outlet back to the tank. Check that the line to the tank isn't blocked or the regulator itself isn't stuffed. Little mud wasps can build nests inside uncapped hoses and sometimes people plug the hoses to prevent this, and forget to remove the plug.