Help with surge in 1hd-ft 80 series Landcruiser motor

[hdj81cruiser]

Hi Fellow 80's series owners,
I have a 1995 80's series with the 1hdft 24 valve diesel turbo engine its a auto......when I first bought It I didnt notice the slight surge it had at around 1600 to 2000 rpm since i've had it the surge has got worse the motor's revs going up and down at the same speed, I've only done 20,000km in it since i've had it and have changed the fuel filter 3 times, the first two changes the surge remained there and seemed to be getting worse, but a couple of months ago I put a new fuel filter on it again and the surge almost completely disapearred but I took it out the other day and it surging as bad as ever I'm wondering if I have a problem or whether i've been getting bad diesel it has seemed to get worse since they completely took the sulphur out of the diesel...I got some advice from a Guy at the local diesel injection specialist who said they had a problem with what he called a power valve causing the motors to surge like mine, but only on the 1hdt 12 valve motor, does anyone know what this power valve is and how to replace it?Also has anyone had a similar problem in there cruiser?

any help would be much appreciated


Cheers
Harley

[Tapage]

I never ear about power valvle .. at least not in mine 1HDT 12V .. did you already check your injectors and spray pathern . ?

Diesel additive for lubircity . ?

[canucksafari]

A very small fuel system air leak can also cause surging. Also, if it is starving for fuel because of a blocked filter, it can surge; but, you would also notice very little power at the higher rpms. Besides your fuel filter, on the denso pumps there is sometimes a small screen strainer at the fitting where the fuel line comes into the pump. There should also be a strainer on the pick-up in your tank. If you have had a poblem with algae blooms, then this could be clogged. I think it is a good bet, considering you have done three filter changes and the last one resulted in an improvement, that your problem is either a dirty fuel system clogging up filters and screen strainers or a small air leak at you fuel filter "o" ring. When you changed the filters did you take a look to see how dirty they were? I'd be careful of diesel injection shops telling you that you need your pump pulled apart.

[roscoFJ73]

Originally Posted by hdj81cruiser

Hi Fellow 80's series owners,
I have a 1995 80's series with the 1hdft 24 valve diesel turbo engine its a auto......when I first bought It I didnt notice the slight surge it had at around 1600 to 2000 rpm since i've had it the surge has got worse the motor's revs going up and down at the same speed, I've only done 20,000km in it since i've had it and have changed the fuel filter 3 times, the first two changes the surge remained there and seemed to be getting worse, but a couple of months ago I put a new fuel filter on it again and the surge almost completely disapearred but I took it out the other day and it surging as bad as ever I'm wondering if I have a problem or whether i've been getting bad diesel it has seemed to get worse since they completely took the sulphur out of the diesel...I got some advice from a Guy at the local diesel injection specialist who said they had a problem with what he called a power valve causing the motors to surge like mine, but only on the 1hdt 12 valve motor, does anyone know what this power valve is and how to replace it?Also has anyone had a similar problem in there cruiser?

any help would be much appreciated


Cheers
Harley

Originally Posted by Tapage

I never ear about power valvle .. at least not in mine 1HDT 12V .. did you already check your injectors and spray pathern . ?

Diesel additive for lubircity . ?

There is only a delivery valve and a regulator valve.Maybe they are talking about one of them??

Harley ,one simple check you can do yourself is check the small mesh filter inside the fuel pump.
Its sits under the banjo bolt where the fuel enters the pump.

They have been known to accumalate crud and cause uneven accelleration.