no starting

[ssc1]

took the car out yesterday after fitting its new gearbox , that went well till the car broke down , no sparks at all , then i tried operating the airflow meter flap in the hope that the fuel pump would run no luck there either , should the fuel pump run with the afm flap moved , i'm thinking that the imobiliser is playing up as there is no sparks at all and no fuel pump running , would this be right, car is 400se , how do i check that the ignition module is ok , seems strange as it stopped twice and i had to get it towed home , just cut out completly .

[wedg1e]

Yes, moving the AFM flap would normally start the pump (ignition on, of course).

There are a few resistance tests you can do on the ignition module and the pickup coil but substitution of the module would be a more definite test.
Certainly if it isn't firing the sparks, it won't fire the fuel either.
I presume you've done the HT lead on the engine block test?

[grahamw48]

If you've been playing with earth straps, worth checking them all. Are they all re-connected properly ?

[ssc1]

yes done the lead on the block bit and no spark and also moved the air flow meter flap and no fuel pump noise , now i know this bit should work as it did on my 350i , but for some reason its stopped working on here. the earth straps are ok as i have done a bonding check on them. so i am wondering if the imobiliser is at fault some how . i went for a run of about 11 miles not fast then stopped for 1 hour then started and ran for i mile when it just cut out no warning no missfire just cut , and checked the spark which was not there, got it running again but dont know what i did , moved a few wires checked the leads l/t and h/t , it ran for about 5 miles and then thats it total failure , engine spins over ok just no spark or fuel pump running , what sort of volts should there be at the ignition module as its gettig about .25v at present .....these things are sent to try us yes .

[SEvans]

Have you checked all the relays has one come loose?

[ssc1]

have not checked relays yet , is there a fuel cutout fitted to these or not , but you may be right about the relays as its some thing which seems to affect the fuel and sparks together , not sure if i heard a small pop or tick when it failed , i could have been hearing things . why dont they fit a nice big computor like on the 747-400 to tell you whats gone tits up..

[wedg1e]

I've been pondering on how you could lose so may bits at once, and one thing that springs to mind is (or are) the two relays marked 'ignition' on the relay board.
Allowing for differences between cars, mine has two relays in the centre of the bottom row, wired in parallel, that energise with the ignition switch to supply all the switched rails.... including the injection and sparks.
On my car the relay bases have melted and the ignition relays have been replaced with separate relays, with the cabling hard-wired to each relay.
It could be you have a problem there.

[ssc1]

isnt it amazing how things happen on here , the relay area is were the problem was . main feed from ign switch ( white cable )goes to a fuse holder with a 30 amp fuse in it and then from there to the relays that you mentioned which supply sparks and fuel , the conections at the fuse holder were very loose , i had got the AFM flapper just open and moved every wire untill i got to this area and then the fuel pump ran and on spinning the engine there was also sparks when i waggled the connector , so thanks chaps and wedg1e got it bang on , very good , and what crap electrics on these cars.

>> Edited by ssc1 on Monday 31st October 17:32

>> Edited by ssc1 on Monday 31st October 17:34