Hello all,

I'm new here so forgive me if this topic has already been covered elsewhere, but I have searched and it doesnt appear that my exact circumstances have been covered anywhere else, unless somewhere I missed.

I have an 02 Punto Mk2 1.2 8v active sport and have only had it for about 4 weeks. A week ago it began to not start. Engine turns over fine but will nto spark. However it only does it intermittently it will start 1 minute and then not the next. Most recently I went out in the morning and started it first time at 07:30 but at 08:15, after being left for 30 mins or so, it would not start. When it does start there are no engine warning lights at all.

Took it to a local garage who were not much use, apart from their electrician stating that there was a fault in the ECU. Whether that means a faulty ECU or a fault in the ECU I dont know.

I currently have the car unplugged from the battery and am going to give it some time to see if it will reset the ECU. I have already changed the spark plugs and the Crankshaft Position Sensor and this has not fixed it.

Can anyone help me diagnose what this is? Would I be best off getting a virgin ECU off ebay or somewhere else and replacing my current one.

Thanks in advance.

Nick

The ECU should reset almost instantly.

The ECUs used on the Mk2 Puntos were rubbish, but they usually fail in predictable ways. This doesn't sound like an ECU fault to me. See the guides for tests.

You can send your original ECU off for testing and get it repaired. This, assuming it is faulty, is a better course of action.

is it low on fuel?
ive had this with some puntos because of this

Is the crank sensor postitioned correctly?

too close or too far away it cant see the timing reference on the phlonic wheel

Have you tried using an Easy start spray? will it start then?

Ziggy

s and b said:

is it low on fuel?
ive had this with some puntos because of this

Click to expand...

Nope got plenty of fuel in there. I did wonder that myself.

Thanks anyway

Nick

Ziggy122 said:

Is the crank sensor postitioned correctly?

too close or too far away it cant see the timing reference on the phlonic wheel

Have you tried using an Easy start spray? will it start then?

Ziggy

Click to expand...

I'm afraid that's going way over my head. The crank sensor bolted into its mount and then plugged into the port at the top. I dont know anything about positioning it.

I've not tried easy start spray but that is something I can look into.

Nick

Air gap between the wheel and TDC sensor should be 0.5mm to 1.5mm (measure with a feeler guage).

OK well I checked that and it is fine. Trouble is it started this morning and last night absolutely fine. And ran fine too. It was a bit stuttery on startup and needed some revs. I wondered if these things had auto chokes and that was maybe the problem?

Nick

Not as such. (Autochokes)

Next time it conks, check for spark and fuel past the injectors. If the TDC sensor fails (and they can fail intermittently) the ECU thinks that the engine isn't turning over, so won't fire the plugs or injectors.

fingers99 said:

Not as such. (Autochokes)

Next time it conks, check for spark and fuel past the injectors. If the TDC sensor fails (and they can fail intermittently) the ECU thinks that the engine isn't turning over, so won't fire the plugs or injectors.

Click to expand...

That's good advice thanks I will. Would the TDC sensor fail though as I've only a week ago replaced it with a brand new one.

It's possible. Unlikely, though. Worth taking a quick look at the connector and the bit of harness to it.

Try also -- if/when conks, a single jump lead from the battery negative to as near to the coilpack as you can.

I have just posted a thread as my wifes car is suffering from what sounds like the same problem.

My thoughts were:

Starter motor
Lambda sensor
ECU

But I dont want to replace all those as it will cost a fair whack!

Have you had any more luck in solving the issues OP?

Rule out lambda sensor immediately. As yours struggles to turn over, I'd also rule out the ECU at this stage.

OK well after a week has gone by where the car was starting every time I got in it and tried it, I have run into problems again.

I tried an experiment and didnt use the car for a week, but went out and started it up periodically to see what would happen. I turned the ignition on, waited for all the warning lights to go off and then started it. It would fire fine, despite struggling a little, if I gave it some revs (to about 2000 RPM or so) within about 5 seconds the revs would pick up and then taking my foot off the accelerator it would settle at 1200 RPM.

Today however I went out to it about 4PM and it started fine, but I thought I'd take it for a quick drive. Came back about 10 minutes later and parked up. Then went out at 8PM and it wouldnt start despite me following the same procedure.

Someone please help I'm about to chuck the thing over a cliff.

Nick

Additional to this I tried the trick of attaching a jumplead to the battery negative to check that it was earthing correctly and this had no effect. Car still wouldnt start.

Nick

its quite possible you have a coolant temperature switch fault
an emissions test would prove or disprove,im sure fiatecuscan would also show if its faulty
other thing is is the car chocking on its own fumes due to piston rings being worn/breather blocked?
can you do a compression test or better a vacuum test on tickover and at 2500 revs once you get it to go again
dont go back to garage with fitters who have big red noses and size 20 boots though

Well those are all things I am not able to do really as I'm not anywhere near good enough with engines or have the tools to do so. Is this something that would display faulty codes though?

Nick

nickblack423 said:

Well those are all things I am not able to do really as I'm not anywhere near good enough with engines or have the tools to do so. Is this something that would display faulty codes though?

Nick

Click to expand...

i cant remember if cts shows as fault code
im suspecting not but to be honest its been a long day ive just finished and my brains fried so logic isnt strong here at the mo
soz

Check again for fuel and spark.

But not hot starting could be engine temperature sensor.

Engine Temperature sensor? Would this cause the engine not to start about 45 minutes after it has ceased being used? If I go out to the shops or something it starts when I get back into it a few minutes later. It seems to be very flippant about when it starts.