Technical multipla turns over but wont fire.

[Tigertamer]

Hey all, We really need some help with our multipla elx 1.6. w reg (2000)
Hubby drove it a short distance in the morning, when he tried to start it a couple of hours later it wouldn't start.
It's turning over but not firing....
diagnostics showed a problem with the knock sensor, which we have replaced but nothing else showed..
We have changed the crankshaft sensor..
charged the battery..
Cambelt looks fine and so does the fuel pump, fuels getting to the spark plugs, and the plugs are sparking.
Error 255 shows on the dash. not sure what that means??
Did a compression test and it is low across all 4 cylinders could there be a problem with head gasket? we are running out of ideas what the problem could be. :bang:

 

[Oletimer]

Hi, I can't help you with error codes, but I had a 16v (2 multies ago) and it almost drove me mad, same as you everything there but not starting, mine was finally found to be the fuel tank creating a vacuum and causing a lack of fuel.
I have no idea how this occurred because it is a vented tank (I believe).
Having looked thru your list of tests, I can't imagine it to be anything else.

George

 

[portland_bill]

How short is a short distance? How long was the engine running?

The fuel injection system will overfuel for a cold start, reducing the extra fuel as it warms up. If driven for only a short distance and turned off, the engine is starting to warm, so needs less fuel, but the temp sensor is not yet giving a signal. So for the next start, it assumes cold and overfuels, leading to flooding. As you crank, to avoid flooding it will gradually reduce the fuel, but if the plugs are too wet it won't fire. This is an issue with all fuel injected cars. I've suffered this when removing the car from the drive to the road, then can't get it back again. Needs to run for a few minutes.

Try removing the plugs, wiping them clean and dry and try again. Hopefully all that is needed.

 

[Townsend]

Had a similar problem which had our car off the road for months. Two independent garages and a FIAT main dealer failed to solve it at much expense. Eventually a Polish guy working from a farmyard found a failure on the inside of the fuel line from the tank where part of the interior had disintegrated and partially blocked the line. The car would start and go, only to stop (at a junction or traffic lights for instance) and fail to start until some time later. Utterly infuriating and totally unpredictable. A very feminine car. And I love her!!! I would like to know what your eventual diagnosis is.