XUD start/cutting out issues

[patersom10]

where do I start...

My ZX is taking about 5/10min to start and is cutting out within 5 min of driving or when the revs drop. you can sit revving it for 5 min will still cut out. once hot will start easier although still cuts out when driving for the first 10-15 min.

Have been running 50/50 veg mix all summer, give or take. sometimes when its been a hot week near to 100% veg. doing 500ish miles a week no problems. as I did last summer in my TGD. one cold morning last week wouldn't start so filled it with diesel and changed fuel filter. started and ran eventually but cuts out.

any ideas, pump failing? its the bocsh one. could I be getting air in somewhere? glow plugs shot?

luckily having my xsara has not left me without a car put prefer the ZX, all advise welcomed...

[Kitch]

Air in the fuel.

[themildbunch]

Sounds like air somewhere...

Unless the pump's had new seals they'll all be getting old now and probably stressed from the action of different fuels over time. I have an old Audi which weeped from the pump head seal - running on bio diesel stopped this leak for a couple of years, until the other seals gave out - has done nearly 300,000 though.

I found when air was getting in before the pump the revs would increase as the pump tried to compensate (this was a Lucas though) - On my n/a Bosch BX when the pump's driveshaft seal started letting in air it would drive OK after a hard start, but after idling for 5 mins + would slowly die... This suddenly got much worse recently with a noticeable leak all over the cambelt and almost impossible to drive unless you keep the revs up and don't stop!

Worth plumbing in some clear line between filter and pump to help diagnose... If it's the pump you may get no bubbles when running but a big stream when you stop - if it's before the pump you'll get a stream of bubbles when running.

[patersom10]

Bled system again now running well, maybe an air pocket missed last time.

Will see how it is at 5am Monday morning when it's cold ! Thanks for the advise.

[electrokid]

Could be a build up of crud from the veg. Check the fuel filter and the bottom of the fuel tank by removing the fuel gauge sender.

Could be air: check where the fuel pipes take a 90° bend around the back of the rear passenger footwell and the rubber bulb priming thingy.

[patersom10]

problem not solved, have ordered new primer bulb with non return valve. so hopefully that will work, cant see an actual leak anywhere.

have done around 300 miles with a bottle of redex in half a tank so hopefully that should blast the crud out.

[Philip Chidlow]

Check the fuel filter housing isn't letting in air anywhere.

[Mothman]

Look at your leak off pipes, if one of them is split, that will cause air leaks. An easy fix.

Andy

[Defender110]

Look at your leak off pipes, if one of them is split, that will cause air leaks. An easy fix.

Andy

Not so, leak off pipes are on the return and just cause a fuel leak and not air in the pressurised feed.

[Mothman]

Ok. i had a similar problem. Found a dirty great split in a leak off pipe, changed it. Problem gone. What was that then?

Andy

[citronut]

Look at your leak off pipes, if one of them is split, that will cause air leaks. An easy fix.

Andy

Not so, leak off pipes are on the return and just cause a fuel leak and not air in the pressurised feed.

apparently the Bosch pump dose not like split leak off pipes, but the Lucas pump runs fine, just makes a mess

regards malcolm

[mat_fenwick]

I'll second that, but I can't explain why! I've had a return line split on the (Bosch pumped) van, and it wouldn't even start as it had lost the ability to draw fuel up from the tank. Yet when I had one fail on the BX when it has the Lucas equipped engine, there were no running issues, just a very dieselly smell which alerted me to it!

[citsncycles]

I'd second the filter housing suggestion - the one on Timex has just failed!