Is my fuel pump too limp?

I've got a 1991 200Tdi and the fuel pump lever is a bit spindly: in fact, there is no spring on it and it has to be pumped up and down. On my old series 3 the pump was like a spring button and when pressed would return to the start. Should my 200 TDI be like this?

Also, I've got ice in my fuel filter. Any ideas how water could get into my fuel system in this weather?

notlight said:

I've got a 1991 200Tdi and the fuel pump lever is a bit spindly: in fact, there is no spring on it and it has to be pumped up and down. On my old series 3 the pump was like a spring button and when pressed would return to the start. Should my 200 TDI be like this?

Also, I've got ice in my fuel filter. Any ideas how water could get into my fuel system in this weather?

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Hello,

You are referring to your fuel lift pump bolted to the right hand side of the engine, at the back towards the bulkhead. This pump works on the principle of a mechanical lever (seperate to the manual priming lever you describe) which is lifted by a lobe on the camshaft. Once the lever has reached the extent of it's travel and the lobe has passed the end of the lever, the lever is then returned to its resting position by a spring inside the pump ready for the next revolution of the cam. The manual priming lever (on the outside of the pump) will only feel like it is working (springiness / resistance) if the engine stops with the cam lobe pointing out towards or slightly higher up than the internal pump lever. (or is it the other way around I can never remember). If you flick the engine over on the starter, you may find that it makes a difference to the manual priming lever. A lot of it comes down to hit and miss as to where the engine stops and the relevant position of the cam.

The manual priming lever however, is no way to test whether or not the pump is working. What you need to do here, is remove the 12v feed wire to the stop solenoid on your injection pump (this will prevent the engine from firing up) and then remove the pipe between the lift pump and the fuel filter housing. Have someone turn the engine over on the starter whilst you watch the opening on the lift pump. If it throws diesel straight up at your bonnet and all over your engine bay, you can assume that it is working fine. If it spits / coughs out diesel but it doesn't get any higher than the top of your rocker cover, or if it is inconsistent, you can assume that the pump is weak and is best replaced. Obviously, if it pumps through no fuel at all, it's knackered.

As for your water problem, well that could be a few things. Water does (unfortunately) collect in your fuel tank and it will increase in volume over time. It usually finds its way into the fuel filter and then into your injection pump where it ultimately ends up in your engine as a finely atomised spray. I'd suggest that you drain your fuel tank completely using the drain plug at the back end of the fuel tank (usually below the filler pipe on the underside corner of the tank) and then fill it back up with fresh diesel. It might be worth checking that your jubilee clips on the filler pipes are all nice and tight, and that the filler neck where the filler pipe meets the filler cap has not rotten through. The last thing that you want is a nice salty brine from our winter roads finding its way into your fuel tank because it will destroy your injectors and injection pump. The fuel filter does have a small plastic drain tap on the bottom which can be unwound, to expel any water that has collected in the fuel filter from the fuel tank as it passes through. I bleed mine every three weeks or so. Keeping your fuel tank full to the brim with diesel will also prevent future water build up because there is less surface area to condensate inside the tank.

-Pos

Fuel pump lever should have some resistance to it, but not be spring loaded. As long as the cam shaft is in the right position it should return to centre but not feel spring loaded.

Can help on your second question

I dont think the fuel pump lever ever has a spring,my 2.5td lift pump is also quite tinny and cheap looking!
The water comes from condensation in fuel tanks,fuel station tanks and your vehicle tank.Using the best diesel you can find and keeping the tank full will help! There should be a little tap on the bottom of your fuel filter to drain water out from time to time.

Thanks guys,

Really good advice as always. When I drain the fuel filter, should I get fuel after the water? i.e. if after the water I get no fuel, is it blocked with ice?

Cheers Ed.

notlight said:

Thanks guys,

Really good advice as always. When I drain the fuel filter, should I get fuel after the water? i.e. if after the water I get no fuel, is it blocked with ice?

Cheers Ed.

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Yes, there should be clean diesel after the water. The drain plug is tapped directly into the central chamber (clean side) of the filter medium, so if there is any muck / particles in the fluid that you drain out, you need a new fuel filter pronto. If there is no fuel flow through to the filter and there are no blockages along the fuel line, or in the steel gauze (if you have one fitted) braised onto the end of the fuel pickup pipe, then yes it could be ice or waxed diesel that is clogging things up. If it turns out to be water, do not attempt to run your engine until you have expelled all traces of water from the fuel system. Modern day diesel is supposed to have additives to prevent it from waxing or gelling in cold weather but I've heard reports of shell diesel waxing up in this cold spell.

-Pos

Cheers Pos. I'll start by changing the filter and fuel, and wait till it's a bit warmer!