Air leak into fuel supply on XUD ZX

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bmw_slayer
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Air leak into fuel supply on XUD ZX

Post by bmw_slayer »

Hello,

I'm now certain I've narrowed down the starting problems on my ZX to a air leak into the fuel supply.

As long as the primer is pumped a few times before starting, the car states very quickly on all 4 cylinders with little or no smoke. After 15 minutes the primer bulb has softened again and you need to repeat the process to ensure a smooth start.

I'm sure it's got worse since I started using the primer (perhaps I've put more pressure on the leakage point). I've read up on previous posts on this topic, but I'm not haing much luck finding the source of the leak... even if I pump the primer repeatedly beyond it hardening up I can't see or smell any diesel.

Can anyone suggest any tricks to find the source of the leak? Is it likely to be before or after the pump (Lucas), bearing in mind that it's causing starting problems?

Thanks for your help,

Mark
97 ZX Turbo Diesel - " This is exactly the car that all New Zealanders should be driving"

AUTONEWS, New Zealand, March 1993
Peter.N.
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Post by Peter.N. »

Try disconnecting the fuel feed pipe at available points and inserting a piece of clear plastic tube, you can then watch the fuel flow for bubbles. If there are some the leak is further back, if not its obviously further forward.

The most likely place is the filter, if it has been changed lately, check that it is sealing correctly, if it hasn't, change it as when it becomes clogged it increases the ammount of suction needed thus making a leak more likely.
philhoward

Post by philhoward »

I'd tried the clear pipe trick, new feed hoses, the lot. It turned out to be the leak-off hoses (the ones which loop from one injector to the next). They still appeared to be flexible, but had started to go hard where they actually sealed (pushed on) to the injector stubs.

I had similar symptoms - once I started to use the primer bulb, it needed it more. It started needing it after a week of non-use. It became after 2 hours of non-use before I finally cracked it.

If you get a length of hose, make sure you also get the litle rubber bung for the last injector...
Stewart(oily)
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Post by Stewart(oily) »

When my ZX was a poor starter first thing in the mornings it needed the priming bulb squeezing about twenty times, the fault was one of the blank stopper plugs on the injector bleed off pipes, a tiny split which could only be seen when the thing was off, a short length of the right braided pipe with a self tapper to blank it off means its a first time starter every time now.
Stewart
BXs since 1993 built 1.9 TZD turbo, got a S2 Xantia estate, brilliant car! 2013, Xantia HDI LX 110 2000 new car with 122,000, l C2 HDI Rusty rocket, C3 Picasso HDI new to me.
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