Contaminated Diesel Pump

Toby_HDi · Unread post by **Toby_HDi** » 25 Jan 2009, 21:59

Interesting reading this, keep up the good work Jim

citrojim wrote:I was happily firing jets of Hydraflush across the workshop with it this evening

I just burst out laughing when I read that...images of you firing jets of Hydraflush with a big grin on your face. Big kid...

Unread post by **CitroJim** » 02 Feb 2009, 20:54

I went down on Saturday to see my nephew Wayne to swap the Lucas diesel pump on his 205. This was his second pump on this car and replaced after the original pump died following some sort of (unknown) misfuel. I stripped his original pump and found the metering valve gummed up and stuck fast.

His replacement pump (fitted by the person who originally sold him the car) only lasted a few hundred miles before it too died in a similar way. Very odd.

Last week, Wayne went to his local scrappy and got another pump off a recent arrival that had driven in to the yard. He paid £25 for it

Swapping the pump on Wayne's very tidy N plate (one of the very last) 205 was pretty routine and after the task of bleeding the new pump, always a pain on a Lucas, it started fine but was running far too far advanced.

I reset the timing by ear on this occasion and next time I go to see him, I'll take my Lucas timing tools and do it properly with the dial gauge.

This timing issue is something to watch when swapping a Lucas pump as they are individually timed and can vary massively pump to pump. Each pump will have a grey plastic clip on the throttle arm with a number stamped into it. This is the timing value and between the old and the new, it was nearly 2mm different. It's almost essential to time a Lucas properly with a setting rod and dial gauge when swapping between engines.

Anyway, his car is now running very sweetly and I'm hoping that'll be the last time we have this bother although I'm a bit worried as the fuel still smells a bit "Duluxy" even after a good flusing...

On Sunday, I pulled the failed pump apart to see what had gone wrong and sure enough, the fuel metering valve was again gummed up and stuck. The pump was also contaminated with some brown rubbish similar to the Bosch pump shown in the first posts in this thread.

I'm of the opinion the pump had been standing around a long time before being fitted to the car and had been standing around long enough for the trapped diesel in it to go "off". This pump was suspicious as it was very clean. Too clean in fact. I reckon it was really mucky and given a real good clean to make it look good for Wayne.

I'm hoping all will now be good and it'll be third time lucky for the pump. Wayne is going to put another tank on though, just to be sure. He's also got no confidence in the car just now and will not have until it's done a good few miles on the new pump.

The moral of this tale is if you get a replacement pump from a breaker, especially a Lucas, don't use it until it's been stripped, cleaned and checked. I'd do likewise with a Bosch too although they will not suffer with stuck metering valves in the same way as a Lucas.

Makes me wonder too, just how may Lucas pumps have been scrapped because of this simple fault and how much this may contribute to their bad reputation...

Brigsygtt · Unread post by **Brigsygtt** » 05 Feb 2009, 17:09

Good thread Jim. Ive always wondered if there are any user serviceable parts inside a derv pump.

Unread post by **CitroJim** » 05 Feb 2009, 23:39

Brigsygtt wrote:Ive always wondered if there are any user serviceable parts inside a derv pump.

The only bit that is easy to change is the stop solenoid and then only if the pump is an early un-armoured one. Apart from things like the fuel filter, that's it really but then again, fed a diet of clean diesel, they tend to be very reliable and often outlive the engine.

About the only thing that happens to either a Lucas or a Bosch is that they become leaky as the seals fail, especially the older ones with seals that are not proof against modern diesel.

The Lucas is very easy to re-seal, the Bosch less-so. Both are DIY jobs provided you work very methodically and in very clean conditions.

Unread post by **CitroJim** » 09 Feb 2009, 10:15

Had a brief chat with my nephew last evening and so far, all is looking good on his 205. It's running very sweetly and he's been taking it on ever longer journeys.

Touch-wood, the problem is now resolved...