306 HDi won't stop

[philt]

Hello,

New to this forum as just become a 306 owner - but have a problem!
The car starts and runs fine but will not stop. Can switch off and remove the keys, even disconnect the battery - car still runs. I have swapped the engine management relay (next to the ECU) still the same. Suspect it's getting a back feed from somewhere - has anyone encountered this problem before?
It makes a change from the usual "HDi won't start" but having to stall the car is a little irritating.
Thanks in advance,
Phil.

[KrisB]

Phil.

Disconnect the multiplugs down by the gearbox which go into the chassis. Big black thing, cant miss em, give them a clean with some electrical contact cleaner and then re-assemble. They often become corroded / dirty /wet. And they're a fire risk.

[philt]

Thanks for the response - have checked the connector this morning, was clean and dry. Gave it a dose of WD40 and re-connected, and it still won't stop!
I have a Haynes manual but am struggling to understand the wiring diagram for the engine management relay (two relays in one). This relay remains energised even when the key is removed. I am more familiar with petrol engined vehicles where normally one relay is used to power ignition (and ecu) and the second for the fuel pump. Is this the same on the HDi?

Thanks again,
Phil.

[philt]

A few more checks - tried disconnecting the alternator small single wire and heavier pair. Separating the two heavy wires will stop the engine which makes sense looking at the manual (removes supply from fuel pump). Re-connected alternator and started looking at ignition switch. With engine running disconnected the ignition switch completely - no effect,engine still running. This should remove supply to coil of ecu relay. The fuel pump relay appears to be switched by the ecu (pin 87) through the inertia switch. So, disconnected inertia switch with engine running, no effect, engine still running! However, with inertia switch disconnected engine now stops on the key, and will re-start ok. The only difference is a noise from the fuel filter housing suggesting that the pump is running while ignition is on (should pulse).
Any thoughts anyone.......................

[Jukie88]

Whitchcraft ??

[Poodle]

This is really weird, been racking my brains on this one since you first posted and i'm struggling to come up with anything definite...

I'd suggest starting by checking and cleaning all your earth points, there's 3(?) on the inside of the wings and one on the gearbox. Have you checked your ignition barrel is working as it should? I'm not great with electrics so can't tell you how it should work, Cully may be able to though. Sounds like you might have a short on the loom between the ign and the ecu maybe..

[aaron_one]

Stall it?

[cully]

have you fitted a radio recently?

check the double fuel relay behind the ECU it may have welded contacts failing that unplug it look for burned loom plug

inertia switch only stops the primming pump

also if the feul pressure reg on the back of the HP pump plays up this can cause engine to run on

[Jonny81191]

he must have ran out of fuel yet....

/troll

[Matt]

Could be dieseling no? Running on its own oil or something? Not too clued up on it myself. Just remember watching a video of Petes ronker estate doing it before he scrapped it

[Poodle]

You'd know from the smoke if it was dieseling.

[rd070707]

Did you ever solve this OP?

[L.J]

i had a problem with a dirty pressure regulator preventing the car from turning off before. worth a try maybe