Occasional long crank time from cold start.

[ScaniaPBman]

The car.

Focus Mk2.5 1.6 petrol auto 10 plate 103,000 miles fully serviced. Bog standard, no mods at all. No check engine light.

The problem.

Every so often when I come to start from cold it takes much longer to crank and start the engine.

Details.

Most times the start is good with the engine running well on what sounds like the 3rd or 4th compression.

At random hard starts there is always the sound of the fuel pump prime and a good healthy cranking speed. The crank time is extended to over 5 seconds, then it fires up cleanly and runs well at the regular idle speed. So far there has not been a failure to start, but next time....?

I have put my basic OBD code reader on and found no stored faults.

Action.

Before I start a random parts replacement exercise starting with the crank position sensor, has anyone got any experience with this type of problem and could point me in the correct direction.

ScaniaPBman.

 

[james1089]

Worth checking the crank sensor isn't loose or bad connection.

[ScaniaPBman]

I've just been out and inspected the crank position sensor as you advised.The cable looked fine and intact. With the connector removed the terminals are clean showing no corrosion.

I removed the sensor itself, a bit fiddley to get the retaining screw out but never mind. There was no obvious damage or visible deterioration.

I am open to further advice.

ScaniaPBman.

[Guest]

I have a 2009 model, it did it on the first day I had it and 3 more times in 2 years. One Ford dealer said it was a software glitch. Another said it was fuel backing out of the engine feed.

Probably still does it but I can live with 4 times in 2 years.

+ it always starts.

[artscot79]

mk1 did this I was told by an old ford tech 30 yrs experience he believed it was an occasional glitch in that the ecu stored the external temp etc which in return effects how much extra throttle to give on start up so if it was reasonably warm and you switch off the engine leave overnight you get in and for a few secs the ecu is still using the parameters from the day before since its a lot colder theres not enough extra choke to start the car

[stef123]

He must have 30 years experience if he's still banging on about chokes lol. 

[iantt]

Chokes, I know a few I could choke. Lol

[ScaniaPBman]

On 23/03/2016 at 11:51 PM, artscot79 said:

mk1 did this I was told by an old ford tech 30 yrs experience he believed it was an occasional glitch in that the ecu stored the external temp etc which in return effects how much extra throttle to give on start up so if it was reasonably warm and you switch off the engine leave overnight you get in and for a few secs the ecu is still using the parameters from the day before since its a lot colder theres not enough extra choke to start the car

Well, Art, I will try to make some connection between the shut down conditions and when it does a hard start the next day. You might just hope that the Ford calibration engineers would have this sorted out by now since there is a fair time between the release of the mk1 software and the mk2.5 software. But there again...........!

All constructive suggestions welcomed.

ScaniaPBman.

[ScaniaPBman]

The random parts replacement exercise has started. I went out purchased a new crank position sensor and replaced the old one.

I will just have to wait and see if the problem has gone away. If I make 2 months without a hard start then the source of the problem has been located.

As always I an open to any other suggestions. Next on my list wil be the camshaft position sensors.

ScaniaPBman.