Owned from new and now 35000 miles. Have lived with problem for over 12 mths.

Starts 1st time when COLD and HOT, but after driving up to temperature and

leaving for between 2 and 3 hours very hard to start. Engine turns ok (new

Varta battery) After numerous attempts it starts with a cloud of white

smoke. The problem is worse in the summer than the winter, so it

seems to be temperature related. Fiat examiner shows no faults and there are

no warning lights on dashboard. I guess this is a sensor problem. Any advice

from technical members about where to start would be appreciated.

Check the egr valve, if it sticks open you gets lots of fuel and very little air which can cause bad starting and white smoke due to the lack of oxygen.
An injector sticking open could also cause this, you need to watch the fuel pressure in the fuel rail on the examiner while cranking when the fault is present. Pressure should be 250Bar minimum.
While it's on the examiner with fault present check crank and cam signal are present, these sensors can fail when hot.

Thanks for your reply, I thought it might be the egr but it is good to get another

opinion. Before replacing or cleaning the egr I will try a blanking plate to see if

that confirms it is the egr causing the problems.

Using examiner or MES: you really need to check the coolant temperature, the air temperature, the map/maf and of course the rail pressure.

You can compare those values with the values you are getting after the car was sitting for 20 minutes after it was working for 20-30 min.
( except the temperatures if everything else is working ok they should be within a very small margin).

I would suspect the rail is loosing pressure, either by leaking injectors (either in the cylinders or on the return ) or a fuel pressure regulator.

Thanks for your input, due to the intermittent fault my local fiat dealer states

the examiner shows no faults.

Thrux said:

Thanks for your input, due to the intermittent fault my local fiat dealer states

the examiner shows no faults.

Click to expand...

You do NOT need to see faults.
the ECU throws errors when the sensors are completely dead or when readings are way out of normal.

You need to read the values and establish by common sense if they are out of a reasonable spec ( a reasonable spec would be when the engine was already running and it easily starts)

Thrux said:

Thanks for your input, due to the intermittent fault my local fiat dealer states

the examiner shows no faults.

Click to expand...

You need to try a different Fiat dealer with a technician that knows how to use the examiner and diagnose faults, not just plug it in and read fault codes.!

Thank you for your input from The Fox and aurick86, unfortunately Fiat dealers

in this part of the UK ( Cornwall) are not very good. They seem to try

to diagnose problems by changing and charging for parts without any regard

to the fault conditions.

I have now fitted a blanking plate to the egr with no change to my starting

problems, except the engine warning light is on. So that rules the egr valve

out,yes.? I have a multimeter where do you suggest I look next.

Your going to struggle with just a multimeter, you need a diagnostic computer that can read live data. You need to view the fuel pressure at the fuel rail when cranking with the fault present. Anything less than 250Bar indicates low fuel pressure. Also look at engine speed when cranking while fault present.
Where abouts in Cornwall are you.?

Cranking speed is good, see 1st post, why do you think it is a fuel supply

problem when it starts 1st time when hot or cold but not, when after being

driven and left for 2-3 hours.

Not sure if Crank sensor has been mentioned, but it seems to fit the symptoms.

They don't throw an error, because as far as the ECU is concerned, the engine isn't turning. The sensor can break down and fail internally.

New ones are relatively cheap, starting around £20, and fitting can be done DIY with a set of ramps and a socket set.

Hi brickfoot,

Thanks for the advice, I have just ordered one and will report back after it

is fitted. Trying to rule out the easiest and cheapest possible causes first.

Have now fitted new crankshaft sensor, no change, next on list is coolant

temperature sender, still starts 1st time when cold or hot but not after 2-3

hours after use. Any qualified advice still most welcome.

You could change half of all the parts in the engine bay and still not get it, this is not an efficient way of troubleshooting an issue.
It would save you a lot of pain, time and money if you would just go see someone who can actually read diagnostics software.
I strongly recommend you stop changing random components and find someone who can tell you what's wrong.

Snails,
I agree with you,but you are just stating the obvious. Considering the hourly rate of main dealers and the retail price they charge for the replaced parts that are not always needed, it seemed a good idea to try and sort it myself. Also as a learning curve with modern sensors.
To recap I have blocked the EGR to rule that out, replaced the crankcase sensor and the coolant temperature sensor without any improvement. My next thoughts are towards the MAP and MAF sensors.
As stated before starts 1st time when cold and hot but struggles to start after being driven and left for 2 to 3 hours,but does start eventually with a cloud of white smoke. Any knowledgeable techs that can point me in the right direction.

Starting problem still exists, the problem only seems to happen when the engine is just warm with the temp gauge hardly moving. As stated before starting when hot or cold is perfect. I thought a tech. could point me in the right direction for these symptoms. If you advise going to main dealer for examiner diagnosis just look at Vospers complaints web page.

Hi, sorry to jump in on your post but I have this exact fault with my Punto, starts perfect when cold and when hot but not when warm. Has been into Fiats three times and has had the heater plugs control replaced, then the plugs and wiring, they then did a leak past test and said the injectors were the problem and it would cost £1400. Took it to an injection specialist and they gave the injectors the all clear. I am now trying to sort it myself, I have checked the power to the heater plugs and found that it's all good cold but when slightly warm they are not coming on, strange thing is they do come on when it starts?? so assuming they should be coming on is it the control at fault which is new or is it the ECU not telling the control unit to power up the heaters??

Hi Marcus,
You are welcome to join in on this post. Two heads are better than one.
Fiat dealers seem unable to diagnose the fault or are just incompetent. I did think there would be some knowledgeable techs. on here that could point me in the right direction. I still live in hope. Surely there can't be many faulty components that can cause these symptoms. Starts 1st time hot or cold but not when just warm.

Thrux said:

Hi Marcus,
You are welcome to join in on this post. Two heads are better than one.
Fiat dealers seem unable to diagnose the fault or are just incompetent. I did think there would be some knowledgeable techs. on here that could point me in the right direction. I still live in hope. Surely there can't be many faulty components that can cause these symptoms. Starts 1st time hot or cold but not when just warm.

Click to expand...

Hi,
If it was a petrol car I'd say vapour lock. (bear with me on this). Some cars wit Bosch K-jet injection suffered from it. When the car was stopped there would be heat build-up under the bonnet causing fuel in the injector lines to vaporise and cause starting issues. I wonder if you have a heat soak (electronics, not fuel) issue. Try a run but lift the bonnet as soon as you stop and see if it makes any difference.
You do really need to get a copy of MES www.multiecuscan.net and a USB ELM327 interface (ebay 271275445368 or 161715574389) and start looking at signals like Temp, MAF, fuel pressure, voltage etc. (MES will draw a graph of several parameters at once that you can store and compare later) and see what is different between a hot and warm start.
MES is only 50 Euros fully registered (you can try it for free) and it does so much more than a code reader.


Robert G8RPI.

Hi Robert,
Thanks for your input. I will try the bonnet lift but I don't think it will help as the fault still occurs if the engine is just warmed up and left to cool.
Fuel vapour lock more likely on petrol than diesel but worth a try.
I have ordered a USB ELM327 interface cable to use with Multiecuscan so will give that a try. Will update after trying it unless anyone else has any bright ideas as to the cause of the problem.