Air leak into fuel supply on XUD ZX

bmw_slayer · Unread post by **bmw_slayer** » 23 Oct 2005, 15:03

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

Unread post by **Peter.N.** » 23 Oct 2005, 15:16

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.

Unread post by **philhoward** » 24 Oct 2005, 10:07

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) · Unread post by **Stewart(oily)** » 24 Oct 2005, 14:27

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