Low voltage to glow plugs?

[Agile]

I would have expected a clogged fuel filter to give Ok driving round town and at low throttle opening but to run out of power at full throttle opening and to give a lower max speed on motorways,

But driving on the motorway seems reasonable but just the general lack of power/accelleration.

Its very marked between the two cars !

No obvious sign of black smoke as I would expect from a clogged air filter . Was also OK on the MOT exhaust test recently too.

 

[Belle427]

pretty inexpensive to change it and maybe run a can of forte treatment through it too to help clean the system out

 

[Agile]

I have now checked and replaced the air filter although it was not very dirty.

If there was any difference then it was not noticeable.

I have not replaced the fuel filter yet but will try to do that soon as its about the only thing left that I can easily check.

However, to recap, the car drives pretty normally apart from the obvious lack of power at all revs. It also does a healthy 56 mpg !

The cam belt was replaced not too long ago so I would be surprised if that was not done at the same time but obviously it may not have been.

What detailed effect does a blocked fuel filter have when driving?

Tony

 

[AlanE]

Tony logic would say if it blocked to any degree it would probably suffer in similar way to an under-gassed gas boiler.

After all both would be running whilst suffering fuel starvation and certainly not give their full output.

 

[Burnerman]

The effect is the same as what you are experiencing Tony - but I'd be most surprised (and very happy) if the performance is restored!
It remains a fact that some engines are better than others....maybe due to the tolerances regarding valve timing etc when they were built.
Its also a fact on earlier diesels that Bosch injection pumps performed better than Lucas ones - and to an extent I can vouch for that.
One small point - when the accellerator pedal is fully pressed to its stop, do make sure the injector pump is also on full bore....the adjustment is on the throttle cable, pump end.
John

 

[Agile]

Yes John I have checked the throttle movement is to the full extent.

My now retired M reg was rather average in performance, the T reg is the problem one and the X reg is what I think of as the sports car performance!

As soon as I get the exhaust on the X reg repaired then I will do my performance test. Thats the time taken to go from 40-50 at full throttle!

I will also see about replacing the fuel filter.

 

[Agile]

I have not replaced the fuel filter yet but have been thinking about this loss of power!

Now its a general loss of power and seems to apply to all speeds and engine revs.

Now perhaps I am wrong but this is what I have been thinking:-

The fuel is squirted into each cylinder according to the throttle setting!

At full throttle the maximum ( set ) volume is injected! One volume per rev!

Now surely the total volume injected per minute at 1000 rpm will be 1000 X X where "X" is the volume per injection?

But at 4000 rpm the volume used will be FOUR times that at 1000 rpm.

So if it is a blocked fuel filter then why is the problem present at all engine speeds INSTEAD of just at 4000 rpm?