Engine Cut Out, speed bump problem

My engine cut out after I hit a giant speed bump going about twenty. I had to push the car to the side of the road then and spent the hour and a half waiting for the AA, looking at leads, etc etc, assuming I had knocked a connection loose. The engine turned on the starter motor but would not fire.

The AA got it going in two seconds - literally - by pressing the fuel cutoff switch which is activated by collisions. I may be v ignorant but I had no idea this even existed. I certainly didn't know that it is the first thing I should try in the event of car not starting after sudden jolt. FYI - it's left of centre in engine comparment towards the back, and is a rubber button in a little metal box.

Interesting, what's your car's spec though?

regards
George

Hi JamieB,

The 2.5TD has the very switch you mention. With the engine idling just tap the side with a screwdriver. The switch will trigger and the engine will stop. As you say, only meant to happen in a crash. What it does suggest however, is that your front spheres are shot and/or your front electrovalve isn't opening. Otherwise the suspension should have been able to absorb enough of the bump not to trigger the switch.

Worth a check. Left alone, the very harsh bumps will accelerate the wear of your strut tops. They are £165 each from Citroen and you can't get them anywhere else.

As George says, what is your model? Why not stick the car details in your signature? That way everyone will know to which model your question pertains.

Cheers.

noz

Hi guys,

do the petrol injection cars have something similar?

I had a prod about and couldn't see one...

Loopy

sorry - been away.

Mine's a 1998 2L hatchback VSX turbo. I think the front spheres are OK - I did wallop this particular bump and normally am careful. Good to have the warning about the strut tops though. Many thanks.

Jamieb

For the record, how do I add details to my signature.

Hi Loopy!!

No no no no S1 cars dont have silly delicate stop switches on them!!!

But seriously, a nice idea to cut fuel in the event of a colision, but if they are that senstive, I'm glad I aint got one!

So no need to worry about it loopy..

If your fuel supply stops it will either be the fuel pump in the tank, or a ruptured fuel line, or a dicky relay that controls the fuel pump, but thats rare!!

Please do not panic...

Regards
citroenxm

Hi Jamieb,

To add anything to your signature click on 'My Controls' at the top right of this screen. Click on 'Edit my signature' at the bottom left of the following page. Type some info into the white box in the middle of the next screen

Hi Citroenxm/Loopy,
The 'Inertia Switch' as its called can be found in the wiring diagrams (item 620)connected to the following ecu/engine combinations:
Bosch MP 5.1.1 ecu XU10J4R (2.0L Petrol) engine
Bosch MP3.2 ecu XU10J4R (2.0L Petrol) engine
Bosch MP3.2 ecu XU10J2TE (2.0L Turbo Petrol) engine
Fenix 3 UFZ ecu ZPJ (3.0L V6 Petrol) engine
Fenix 4 UKZ ecu ZPJ4 (3.0L V6 Petrol) engine
Bosch Motronic MP7.0 ecu ES9J4 (3.0L V6 Petrol) engine
(no ecu) XUD11A (2.1L Diesel) engine
(no ecu) XUD11ATE (2.1L Diesel) engine
Bosch MSA 11 3.6 ecu DK5ATE (2.5L turbo Diesel) engine
EGR ecu XUD11ATE (2.1L Diesel) engine
Bosch MSA 11 7.6 ecu DK5ATE (2.5L Turbo Diesel) engine
Lucas DCUP2 ecu XUD11BTE (2.1L Diesel) engine

Whilst early variants did not have iertia switches it looks like from RP6568 onwards it was included. It must have been some legislation date or something.

Cheers

noz

I had a similar experience to Jamieb. I was driving along our rather rough track to the road when I hit a large stone underneath. Dead stop. The AA had been foolish enough to give me free 'home start' for my 'longer than I care to remember years of membership' after the stautory hour or so the nice man arrived and started peering in his book, "does it have a fuel cut out" he said, "not to my knowledge" said I. But it did and he found it, just by the top of the o/s strut. I must admit though it was a very abrupt stop, I half expected the air bag to have gone off!

Peter.N.

Not to muddy the waters any, but I had a problem with my S1 2.0i where it would randomly cut out when going over harsh particularly bumps or even when the bonnet or doors were slammed (in frustration normally! ).
After weeks of tearing my hair out trying to find the cause (suspected the ignition amplifier box on the back of the distributor), it eventually turned out to be a loose / dirty connector, that was nicely hidden under the LHM tank.

I had an LHM overflow out the top of the reservoir shortly after acquiring the car, thanks to the previous owner overfilling it (didn't check the level with the suspension on high I think), and the wiring below (cracking placement, I must say) was generously coated in the stuff. After a thorough cleanup and firm reassembly of the multiplug, the problem never returned. I suspect that the plug had been loose, and the vibration of the engine and road was causing it to intermittently disconnect, which would also explain how the LHM had penetrated the inside of it.

Not saying its this, but just one more thing to consider if you're experiencing engine death and the inertia switch has been ruled out.

This post has been edited by Ciaran on November 29, 2006 02:41 pm

I am a new member from France with a XM, petrol, from 1993. Old lady who got a new engine blok which now has run about 70.000 km. I have periodical problems to start. The engine is turning, plenty of battery, but no egnition.
I don´t know how to solve the problem. One should think, when pumping the accelerator pedal at the same time as the engine is turning there should be a smel of petrol. But there is nothing. What is the most logical problem ? The pump in the tank?
Looking forward to hear your advise.
Torben

Hi. Torben.

I guess by 1993 your XM is fuel injection rather then carburettor. In which case, pumping the throttle will not (or certainly should not !) produce any smell of petrol.
Have you found out whether the ignition system is producing a spark for the plugs ? If you have a timing (strobe) lamp, connect it to one of the HT leads, turn the engine over and see if it flashes. If you don't have a lamp, take a plug out, attach the plug lead, rest the thread section on a bare metal part of the engine and have someone crank it over while you watch for a spark across the electrode.
If you have a spark, next issue is to check for fuel. The last petrol XM I owned had an intermittent fault in the power feed to the tank pump. Normally you will briefly hear the pump run when you first turn on the ignition. If not, check the feed. Pump is accessed from under the RH back seat. I'm sure one of the other members will be able to give you the correct wires to link to. If there's no 12 volt, rig a temporary feed and see if your problem then disappears. DONT do this with the pump out of the tank, but over the opening --- an odd spark could be catastrophic !! Good luck.

Mike.

Hi everybody,
The engine cutting out due to relay problems seems to be common on S1's. My V6 was cutting out and failing to start. The problem was based around a relay which sits on the front of the control box. This relay has a number of functions one of which is to control the fog lights. The relay had burn marks around the legs. I swapped it for the same unit on my other car. To test that it was the cause of the problem I repeatedly substituted it for the good one. Each time I put the dodgey on back within seconds the engine would die and refuse to start.

If it's the "Bitron" relay mounted on the front curve of thewheel arch in front of the ECU box, it is well known to cause trouble on the S1. Removing and cleaning the contacts MAY cure the pronblem but that is very improbable and the only cure is to replace.

I bought a XM off Ebay that had a strut through the bonnet, this was showing an immobiliser fault. It was the fuel cut off switch. Could have been jorgy9 that put me on to this.

Steve.

2.1TD S2.