Technical Old Newbie needs help - Stilo won't start

[Blencogo]

Happy New Year everyone - my first visit so please be gentle. I used to understand cars about 30 years ago but things have moved on...........

Anyway, 3 door Fiat Stilo 1.6 16V Aircon 2003. When driving home just before Xmas on a very dark wet night, I hit some standing water in a dip in the road - quite deep, over 1 foot. I drove out of the water slowly and everything seemed OK. The next day on driving to work (18 miles) I started to get a slight missing particularly at low revs. It was nothing alarming but a bit disconcerting. On the way home the missing continued, I filled with petrol, then the engine MIL light came on accompanied by loud warning ding.

Next day OBD scanner reported one fault - Cylinder 1 Miss - so I removed the coils and noticed No 1 plug recess was half full of ice. Hairdryer to the rescue - dried the recess, cleaned all plugs and reassembled. Cleared Error Code.

Now it won't start and I'm not sure what to look for. Tried drying electrical connections in the engine compartment, resetting the fuel isolator. There are no errors showing but when I try to start it almost catches, but not quite. Cannot smell much petrol at the exhaust pipe. Could it be the fuel pump? Could this be damaged by water and ice? Is it easy to check.

Would appreciate your suggestions - not sure I can afford Fiat Dealer's prices!!!

 

[Deckchair5]

You might well have a coil gone or two if it's trying to start but not quite catching. More difficult if the engine isn't actually going at all but obviously coil No 1 is chief suspect.

Might have to find out the bad one/s by comparison when checking resistances at the coil pins


Check them all and you should be able to compare and spot the bad ones. Fiddly but not too difficult. Very easy for a garage with a scope to identify a bad one
Or remove the plugs after an attempted start and see which ones are wet with fuel

Fuel pump is in the fuel tank on yours so not much chance of problems with that through deep water

 

[Blencogo]

Thank you for your detailed reply.

Unfortunately all the coils appear OK with the meter. I can't do without the car so I'll phone the Fiat dealership tomorrow to collect and (hopefully) cure.

Can't help feeling it's not getting fuel.

Thanks again.

 

[Deckchair5]

If the plugs are wet then it's getting fuel and not firing.
Are you sure you replaced the low voltage connectors to the correct coils?
Is the immobiliser warning light showing on the dash gauges as that will prevent ignition?
Any new fault codes?
Rpm sensor might be suspect as that's a bit exposed and without that it won't know when to fire so it won't

 

[Blencogo]

Thanks again for your help.

As it sounded like it wanted to start, I recharged the battery and strapped another on in parrallel and cranked the starter for about two minutes and - miracles of miracles - it started. Obviously a sticky valve and nothing to do with the water bath! Odd how you can be deflected by another fault.

However, I still have a misfire on 1 cylinder and as it is a different cylinder than originally, one coil must be malfunctioning even though it seems OK with a meter. (I forgot which coil came from which cylinder when I merered them).

I've ordered a replacement and a new set of plugs. There are disadvantages to living in the middle of nowhere!

Thank you again.

 

[h2ypr]

Could it have still been water in the system and by continually cranking it eventually cleared/evaporated it?

Ross

 

[Morty Mort]

Pull out the plug you suspect is faulty and try to idle it at 3 cylinders.

M.