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Changed engine now won't start
Posted: Wed Mar 13, 2013 9:19 pm
by mattnorman
Hi all,
I unfortunately drove my 2003 406 2.0 S HDI 90BHP peugeot through a small flood and got stuck. After a recovery back to my garage, we managed to get the car started but it had no pull so diagnosed that conrods were probably bent. Now we have swapped the engine and kept all the original ancillierys but we cant get it started. When we turn the ignition, the starter motor turns but the car never starts. We have tried to use a ODB2 diagnostics kit on the car but its not recognising that its connected - but not sure if this was a problem before the engine was swapped. I'm guessing electrics/ECU but if anybody has any pointers where to start it would be great. Thanks
Re: Changed engine now won't start
Posted: Thu Mar 14, 2013 8:08 am
by V6Exec
Did you do a mechanical only swap or did you take the electrics (ecu etc) from the donor?
If you took ECU as well it could be the immobiliser.
Re: Changed engine now won't start
Posted: Thu Mar 14, 2013 9:34 am
by mattnorman
No it was only the bare engine swap. All electrics and ancillieries were kept from the original engine
Re: Changed engine now won't start
Posted: Thu Mar 14, 2013 10:11 am
by steve_earwig
Even the crank and cam sensors? Any chance the cam timing is out?

Re: Changed engine now won't start
Posted: Fri Mar 15, 2013 12:30 pm
by mattnorman
Yes everything was swapped. The cam timing should be ok, it all turns smoothly and the starter is also turning it. Just doesn't seem to want to fire up after that.
Re: Changed engine now won't start
Posted: Fri Mar 15, 2013 5:06 pm
by steve_earwig
Does it have a safety cut out on the suspension top nearest the battery?
Re: Changed engine now won't start
Posted: Fri Mar 15, 2013 8:26 pm
by mattnorman
I have looked for one before and I couldn't see it, not sure if its got one.
Re: Changed engine now won't start
Posted: Sun Mar 17, 2013 4:03 pm
by mattnorman
Still not got it working. Anybody have any ideas where to start looking?
Re: Changed engine now won't start
Posted: Sun Mar 17, 2013 5:03 pm
by Captain Jack
Wasn't there a fuse that can go pop which would stop the car talking via OBD port? Wouldn't stop it from starting though.
Re: Changed engine now won't start
Posted: Sun Mar 17, 2013 7:53 pm
by mattnorman
do you know which fuse that is or what it might be labelled as?
Re: Changed engine now won't start
Posted: Sun Mar 17, 2013 8:00 pm
by lozz
As said above, check the inertia cut off switch
All 406s have them, square red button on the passenger side nr battery
Suspension. Leg area,
Also have you checked the cam and crank sensor,
And double relay in ECU box,
Re: Changed engine now won't start
Posted: Sun Mar 17, 2013 9:29 pm
by mattnorman
i'm not sure mine has an intertia cut off. i have looked at some photos of cars with this switch and mine appears to be missing. could it be located elsewhere? how can i test the cam/crank sensors? all the plugs appear to have some voltage and are connected. is the double relay the extra connector inside the box with the ecu and how can i test/bypass this? thanks
Re: Changed engine now won't start
Posted: Tue Mar 19, 2013 11:32 am
by mattnorman
i've been looking at the car again and i can't see any relays in the ecu box either. if there is an obd fuse, does anybody know what it would be labelled as?
Re: Changed engine now won't start
Posted: Tue Mar 19, 2013 1:53 pm
by womble171
I was having the same symptoms with my 406 110hdi.
I have had, and still am having a nightmare with my car.
Try towing it to start it (unless its an automatic).
Apparently, the cams can go into sleep mode and forget how to start. Towing wakes them up again???
I was a bit sceptical when i got told but i had tried everything else so thought what the hell, I nearly
peed my pants when she started!!!
Still got big problems with the car now but she starts with the key now evertime.......just doesnt stay like that for long

Re: Changed engine now won't start
Posted: Tue Mar 19, 2013 2:00 pm
by lozz
I've never towed a derv even after fitting engines
A bit of easy start ..ahem. brake cleaner, is all I've used
Ithink you may have just built up fuel pressure perhaps by towing yours
Womble,