Xantia Blocked Injectors?

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davidjgray308
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Xantia Blocked Injectors?

Post by davidjgray308 »

I have a 94 Xantia 1.9D (lucas pump) that is lacking in power even for a 1.9D.Not long after acquiring it, I experimented with vegetable oil refined using a transesterification process. Soon afterwards I began to experience a lack of power and also a situation where the idle speed would drop to around 900rpm on coming to rest and then a second or so later would pop back up to 1000 instead of coming to rest smoothly (anyone familiar with this situation?). I'm told this was down to a blocked injector and have used much injector cleaner and more or less got rid of it although it is not like before I used the veg oil. I have also been through a number of fuel and air filters but power still seems to be lacking and not delivered smoothly. I have tried injector cleaner direct in the fuel filter housing instead of mixed with fuel. I know now that veg oil shouldnt be used with Lucas pumps - is it possible the pump is damaged in some way or is it more likely the injectors are still blocked, despite my zealous cleaning? Many thanks in anticipation, Dave.
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CitroJim
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Post by CitroJim »

Hi Dave,

Welcome to the forum :D

Generally, diesel injectors do not block. There's too much pressure behind them to

Yes, I'm sorry to say the pump is most likely damaged. I've just stripped a Lucas pump that died running bio-diesel and it was in a terrible state. They're delicate little flowers, these Lucas pumps and very intolerant of anything but the finest diesel.

I have no proof it was the bio-diesel that was the the full cause of the failure of the pump in question but the pump was full of corrosion and muck. Have a look at this thread, from post 10 onward where I go into more detail on what I found inside this particular Lucas pump. What I thought was just dirt in some places has turned out to be corrosion as well, suggesting the bio was a bit watery.

The symptoms you have point to a sticky, gummed fuel metering valve and the pump I dismantled exhibited similar symptoms to yours just before it died.

The lack of power may be down to excessive leakage in the distributor rotor through inadequate lubrication; they eventually seize in the rotor sleeve if run on veg for an extended period. Even short spells of veg running will wear the rotor and sleeve.

A golden rule with Lucas pumps is to never run them on anything but diesel. If you really want to run on veg or bio-diesel, do a Bosch pump conversion.
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
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