Changed engine now won't start

[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

[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.

[mattnorman]

No it was only the bare engine swap. All electrics and ancillieries were kept from the original engine

[steve_earwig]

Even the crank and cam sensors? Any chance the cam timing is out?

[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.

[steve_earwig]

Does it have a safety cut out on the suspension top nearest the battery?

[mattnorman]

I have looked for one before and I couldn't see it, not sure if its got one.

[mattnorman]

Still not got it working. Anybody have any ideas where to start looking?

[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.

[mattnorman]

do you know which fuse that is or what it might be labelled as?

[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,

[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

[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?

[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

[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,