Fiat Coupe 16vt starting issue

[AJ]

Hi all, it's been a while :)

I am having problems starting the Fiat 16vt (in an Alfa 145). I haven't started the car for just over a month, and I went to start it on Saturday - the battery was flat so I charged it the night before and it came up to 14v OK.
When the car has been stood for a while I usually pull the connectors from the coils and crank it to get the oil round before reconnecting and firing. I did exactly this on Saturday, but it woouldn't start when I reconnected them. Sometimes it does a little cough and splutter after 2-3 seconds of cranking, but it won't catch properly. Normally it fires and runs after about half a second.

- I have a spark on all 4 plugs
- The fuel rail is pressurised (I can hear the pump prime and can feel the fuel flowing in both pipes).

I guess this is likely to be a sensor issue, but I have reseated all of the connectors I can find and checked for corrosion etc, but I can't get a code reader on it until next weekend. Can anyone think of anything else to try in the mean time?

Thanks

[AlfaJack]

Do you know if fuel is entering the bores?
Strong sparks?

I found I would get some sparks when the crank sensor died. Perhaps measure the resistance on the sensor plug.

Has it got an immobiliser?

[AJ]

Hi Jack,

It hasn't got an immobiliser. I took out each plug and they were all the same - slightly black from previous use, slightly damp because of the fuel - so yes it looks like fuel is being injected.

I suspect crank or cam sensor as I'm sure I have read these will stop it starting, but I also assumed it wouldn't spark either. Is there a guide to testing for each one?

[AJ]

Update - she runs :hyper:
It was a faulty spark plug in cylinder 3 (open citcuit) :huh: Of the numerous tests they had on Sunday, last night and again this evening to confirm a spark on all 4 leads, I used a plug I had on the shelf in the garage - of course this worked. I even removed the plug from number 1 cylinder to test on all 4 leads, great. One thing I didn't do was remove and test each plug independently. School boy error! :blush:

I guess I got thrown as it hardly even attempted to fire I didn't suspect just one plug to be down. I even tried my spare ECU but with the same result. Now to re-fit everything I've removed unnecessarily..

[AlfaJack]

Ah well, alls well in the end!

[Steve Webb]

Just goes to show that the smallest thing can really throw you. I guess the dead plug was causing more problems than just not firing.