Synergie fuel leak problems (again)

[Ianhw77k]

I'm having trouble with air in my diesel system again and I can't get to the bottom of it. It's a 1995 citroen synergie with the 1.9td lump in it. I'll take you through what's happening and what I've done already.
Yesterday we rebuilt the rear brakes as I'm having some issues in that department, we finished up and my dad decided to go speeding up the road to check them. That's a whole other story but he parked it up and we all went in to get washed up. Then I went to go home and the engine wouldn't start. It turned over but wouldn't fire. We pumped the priming bulb and found the system had no pressure but we could get it started with the right amount of pumping at the right time. It would run for about a minute then stall.

I've come back to it today armed with some hoses and clips. I've replaced the flexible hose from the feed to the priming bulb, then from the priming bulb to the right angle piece that connects to a harder plastic hose that runs to the filter. I also had the filter housing apart, cleaned it and checked it. Put it all back together and still have the same problem.

One thing to note, when I pressurise the system with the priming bulb, I can hear a faint, high pitched noise coming from somewhere but I can't see any leaks. Does anyone have any ideas?

[Ianhw77k]

OK, it won't even start after priming today, even when I took the cut off solenoid out of the equation.
Does anyone know where the lift pump is located on this car?

[Xantidote]

I'm not sure what system the Synergy has, but the 1.9TD in my Xantia, 4 years older than your vehicle, has the Bosch system, and it doesn't have a lift pump. Instead, the injector pump provides the suction to lift the fuel into the pump. This is why on systems such as mine, any air leak into the fuel line allows fuel to run back to the tank.

If your system's like mine, I'd suggest you check the injector leak-off pipes. They harden with age, and would always be on my check list.

Does your engine have an injector with a wire to the top of it? Later TDs had this, which links into the electronics. If the wire's loose/broken, then the ECU may not allow the engine to fire up. Other members should be along shortly who'll know more about this later version.

[Ianhw77k]

That could explain a lot. I can't see any connectors to the injectors and I do have the bosch system. I changed the return pipe so apart from the feed pipe that runs across the top of the engine, and the leak off pipes, everything has been changed. I also wonder if the large O ring seal on the bottom of the fuel filter housing might be defectiv. I'm giving up and getting it towed to a professional, I've been on it for two days straight now and it's getting disheartening. I need it to get me to Plymouth and back in a few days and I'm running out of time.

[Ianhw77k]

I cracked the injectors as well, a few times and nothing is getting through

[Xantidote]

Sorry, I mis-read your first post - your car must have virtually same Bosch system to mine.

I still think you should cast eye over the short small diameter injector leak-off pipes.

I assume you are having difficulty generating any sort of pressure when squeezing the bulb? If you were to crack the 4 screws securing the top of the fuel filter, do you get fuel flooding out when the bulb's squeezed? (put rags around to soak spillage). Just thinking this would help trace how far the fuel's getting. Of course, it is always possible injector pump needs attention. Have you tried bleeding the low pressure fuel line at the banjo joint where it connects to the injector pump, by just cracking the bolt?

How many miles has the car/system done? Have you been running it on any fuel other than diesel?

Another possibility could be that the (gauze?) filter in the fuel tank is blocked up, and restricting flow of fuel. This is accessed after removal of offside rear seat squab. Have always run my car on road diesel, and never had to check fuel tank filter on my car, now on 190k.

Let us know how you get on, and what you or your mechanic discover is at fault. Always frustrating until you pin it down

[Ianhw77k]

I'm getting fuel through right up to the pump but nothing to.speak of at the injectors. I could replace the leak off hoses myself but if that isn't the problem then I've just wasted another day. I still haven't got the brakes sorted yet so maybe I can get the mechanic to sort them as well, I just couldn't get the air out of the system. At least I know I can trust this guy, he specialises in citroens. His prices are reasonable as well.

[Ianhw77k]

Oh yes, the mileage is around 187k, and the only way to access the tank is to drop it, there's no inspection hatch and it's got about 60litres in it, I don't fancy that job on the roadside.

[ekjdm14]

stop solenoid/immobiliser fault then IMO if there's fuel at low pressure side but nothing on high side on cranking.

[Ianhw77k]

Thanks for that but I checked the stop solenoid, even removed the plunger and tried it without and the immobiliser has been disconnected for about two years now.
I really hope it's not the injector pump.

[Xantidote]

I keep thinking yours is a Xantia, rather than a Synergie, so my comments re fuel tank probably irrelevant. And as you say, with 60 litres in the tank, it would in any case make it much more difficult to remove tank.

With getting fuel right up to the injection pump, it does suggest the pump is where you should be looking. Just cross fingers that your mechanic finds something we've all missed. Good luck.

[Ianhw77k]

Just had a call from the garage. They say they had it running for about 10 minutes but then it cut out again. They suspect the immobiliser gubbins on the injector pump and reckon it could need another pump. It has the old style, keypad immobiliser which I disconnected about two years ago. Now I'm wondering if there's any way of removing this without having to replace or remove the pump?
The worst thing is, I need to get to Plymouth tomorrow for a camping trip, looks like I'm going to have to hire something as there's other people relying on me for a lift en-route.

[Jaf]

Er. When I changed my leaky pump I had to change the stop solenoid over from the old pump to the second hand one. So if you've a problem with the electrics you might be better off bypassing the lot. Have you already got the armour off?

[Ianhw77k]

Sorry for the late reply, I've been camping for the past few days.
There's no armour on this one, it's too old for all that. There is some sort of little black box of tricks on the end of the injector pump which has a wire going into (or out of) it. Nobody seems to know what its purpose is. I had to hire a van for my trip which I will be returning tomorrow morning and the garage is a short walk from there so I'm going to have another crack at it. I just remembered another thing that, at the time, I didn't think worth mentioning as I thought it was just another coincidence. When I had it running before, twice it conked out as I slammed the bonnet shut. I think there is an electrical socket and plug that is corroded and causing problems, I'm just not entirely sure if it is connected with this problem.

I just wish the car was here so I could post some pictures up.

[Ianhw77k]

I will attempt to upload some pictures of the injector pump with its little black box. I'm on mobile at the moment so this could all go horribly wrong. The main thing that bothers me about the solenoid being suspect is that I removed the plunger from the solenoid housing to allow free flow of fuel and I still had the same problem. Is there any chance that the immobiliser on this one doesn't work on the solenoid but on a different part of the pump?