Car Not Starting 1st Time

[panthro]

Hi All

My 172 is not starting in the mornings 1st time. It used to start first time, but now the starter motor will just keep going and it will cough and splutter trying to start. But after I turn the key a second time it starts with no problems! Any idea whats causing this? I had the key turned this morning till it spluttered to a very rough start and all the warning lights came on! They turned off after about 2 mins, but it got my slightly worried. Its due a service in 3000 miles....maybe it has something to do with the oil and filter needing to be changed.

[Tripps]

panthro said:

My 172 is not starting in the mornings 1st time. It used to start first time, but now the starter motor will just keep going and it will cough and splutter trying to start. But after I turn the key a second time it starts with no problems! Any idea whats causing this? I had the key turned this morning till it spluttered to a very rough start and all the warning lights came on! They turned off after about 2 mins, but it got my slightly worried. Its due a service in 3000 miles....maybe it has something to do with the oil and filter needing to be changed.

Doesnt sound oil or filter related, unless the oil was so thick that the engine is struggling to catch - in which case you would be very worried.

Sounds spark, coil or injection related to me, but I could well be wrong.

[r5gttgaz]

Whats it like firing up when its warm? Could be a faulty coolant temp sensor.

[trickywoo]

Its not anything to do with the oil....could be the plugs but most of the time its the oxygen sensor.

Its there to stop unburnt fuel going through the cat. If its dicky or the last time the engine was run you shut it off before the cold start cycle was over the ecu could be supplying too little fuel on the next cold start.

[panthro]

r5gttgaz said:

Whats it like firing up when its warm? Could be a faulty coolant temp sensor.

absoloutely fine. no problems at all.

[rpla102]

Having similar problems with my 172, Won't start first time, fires up, then dies. Then it will go fine. Just had its 72000 mile service so shouldn't have thought it would be anything to do with that!
When its warm its worse, takes a good few attempts to get it to go.
Going to the garage tomorrow morning so will let you know!

To be honest I thought I bought a lovely car, but its just proving totally troublesome, and its not from a lack of money/time being spent on it! Love the car hate the reliability issues!!

[rpla102]

Been to Garage, Immobilser crocked, going in for repair in the week.

Fairly simple really!

[Mr Jenks]

panthro said:

Hi All

My 172 is not starting in the mornings 1st time.

172's have always suffered with coolant temp sensor problems. They give incorrect infomation to the injection computer, making it think that it is warm and reducing the injector opening duration, therefore the ammount of fuel going in. Like trying to start a carburated engine with no choke. Less likely but also a fairly unreliable part is the crank sensor on the clutch housing.