V8 Crankcase Breather blocked?? Fuel Pump always on??

Hi Guys

I have been checking round my 1998 RRC 3.5 EFi SE Vogue to try to trace the source of my idle problems when hot. It starts and runs sweet as a nut apart from this.

Two things I have discovered which may or may not have anything to do with it, but are puzzling me are:--

Crankcase Breathers

When I checked the crankcase breathers, the flame trap on the left as you look at the engine was fine.

When I looked at the one on the right (under the throttle linkages - see picture) the foam was as clean as new, and when I checked there was no hole down through the middle of the base (item 7 in the picture). So the breather has been blocked from new.

Three questions:-
(a) is this a machining error, or intentional? But if it was supposed to be blocked why put the filter element and cage on top of the base plate?
(b) Should I drill a hole through? Will it out make any difference to the running of the engine?
(c) If so, does the base unscrew from the valve cover? I don't want to drill it in situ and drop swarf on the valvegear, and if there is going to be little or no difference to the running of the engine I don't want to go to the trouble of removing the valve cover.

Fuel Pump Always On

The Fuel pump always comes on with the ignition, whereas I understand it should only come on when the engine is cranked or running, controlled by 5deg plus of movement in the flapper in the Air Flow Meter.

It looks like someone has been in the AFM before me (top cover sealed down with mastic and a cable tie round it) so maybe it has been bodged to cure a fault in the AFM switch?

Is this worth worrying about?



As always I will be very grateful for any comments or suggestions you may have, as I haven't found any answers by the usual searches.

Cheers

Pete

Fuel pump should come on with ignition for a few seconds to pressurise fuel rail. 3.5 bar ready for start up. It is the diesel lift pump that comes on when glow plugs are active or when engine is cranked or running. Not much point in a breather that can't breath.

wammers said:

Fuel pump should come on with ignition for a few seconds to pressurise fuel rail

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Thanks Wammers.

The pump comes on with the ignition (without starting the engine) and stays on - it just gets quieter after the initial surge to pressurise.

The Haynes manual says "... it is only energised when the ignition is switched on and the engine is running or when the starter is cranking." So this is different from your description. Maybe there were different versions?

Pete

Pete The Biker said:

Thanks Wammers.

The pump comes on with the ignition (without starting the engine) and stays on - it just gets quieter after the initial surge to pressurise.

The Haynes manual says "... it is only energised when the ignition is switched on and the engine is running or when the starter is cranking." So this is different from your description. Maybe there were different versions?

Pete

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Haynes manuals are not my favourite reading. Are you sure you were not reading the description of the diesel lift pump sequence, it sounds about right for that. I would get a copy of RAVE and look at that. I am not too well up on the petrol version. The copy of RAVE i have only covers the 4.6 litre engine. The description of the operation of the later 99 on system says, when engine is cranked pump is activated until 3.5 bar is achieved then turned off, until engine starts. Maybe your earlier version is different.

all the efis come on for 4 sec then go off until you try and start

jamesmartin said:

all the efis come on for 4 sec then go off until you try and start

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Yes that's what i thought, comes on to pressure rail then cuts out until engine cranked or is running and power feed is supplied by alternator.

Thanks James and Wammers.

Irrespective of what should happen, do I need worry about the pump being on all the time the ignition is on?

Also is it worth doing anything about the breather, bearing in mind it has presumably been blocked off for the last 22 years?

Pete

Pete The Biker said:

Thanks James and Wammers.

Irrespective of what should happen, do I need worry about the pump being on all the time the ignition is on?

Also is it worth doing anything about the breather, bearing in mind it has presumably been blocked off for the last 22 years?

Pete

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You can if you want to, personally i would. But just think how much it's saved you in gauze filters. The filters look to me like inlet filters, were crankcase air is sucked out to the inlet and through the engine and fresh air is drawn in through them. Don't know about pump to be honest, pressure control is located in pump according to RAVE whether it is supposed to switch pump off after initial pressurising or just unload pump i don't know. Certainly later versions appear to switch pump off after pressurising, your rearlier version maybe different. Someone on here must know the answer your after.