Car not starting on first couple of turns of the key

[Dom9]

Got in the car this morning and it took, literally, 6 long turns of the key before it fired!

It has only ever done that once before (recently) and that took 3 long turns.

The battery is new and in good condition (thankfully) and the car has just been serviced and is generally running well.

When it did finally catch, it settled straight down to a good idle and ran fine... No problems through the rev range etc...

Could it just be that it was a bit damp, having been left in the rain overnight...?

Or could there be something more sinister afoot?

The fact that it runs fine suggests to me that the spark/ coils are fine, so perhaps it could be a sensor? TDC maybe?

Any thoughts?

Thanks!

Edited for dreadful spelling/ grammar!

 

[Greeny.]

Plugs? Did they get changed at the service?

 

[Geddes]

Could be the alternator not putting enough charge in the battery. even though it's a new battery it could of been standing on the shelf for a long time and lost abit of juice, could be worth putting on charge again just in case

 

[fosbrook6695]

Starter motor? Give it a GENTLE tap while turning the key, worked for me so i just got a new one. Starts perfectly every time nw! Only 98 quid all in

 

[MikeyK18]

TDC Sensor?

 

[Nickharding]

TDC Sensor?

 

[MikeyK18]

Echo in here?? :rasp:

 

[Nickharding]

Woops, must have posted at the same time

 

[Dom9]

LOL - Thanks chaps.

Sorry for the slow reply, been away for our anniversary.

The starter turns over fine, so I am pretty sure that and the battery/ alternator are fine.

I have been listening out for the fuel pump to prime and that has been ok (having said that, the last 4 times we have used it, it has started first time except for once, when it was secind time) so I think it must be a sensor.

It's just weird that as soon as it does fire, it seems to run fine and not be a little more temporamental. Having said that, the Airbag and Service lights do tend to make regular appearances now, so it's not all good!

Spark plugs weren't changed and the last service but were about 10k ago. I didn't own the car back then, so I will change them and the leads next time (this year) for peace of mind. They could be Bosch ones or something in there, I guess?!

Will keep an eye on it over the next few days and see if it gets any better/ worse. As I understood it, 172's are usually pretty good at not having starting problems etc, right!?

 

[Sean6545]

Sounds like the Crank sensor to me, (TDC sensor) Get it replaces with the new blue type along with the new loom.

 

[Just Bob]

Sounds like the Crank sensor to me, (TDC sensor) Get it replaces with the new blue type along with the new loom.

+1

When and if you do replace the TDC sensor and loom, make sure you get the wires connected correctly. The wire colours are going to be different. Read the code on the old plug A & B and make sure you connect the wires to the new plug A & B, just dont join a yellow to yellow THEY WILL BE DIFFERENT!!
If you don't it WILL not start!

 

[Sean6545]

^^ knows it

 

[Dom9]

Good info - Thanks chaps!