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Technical Punto MK1 ELX Convertible 1.6 88hp help!

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Technical Punto MK1 ELX Convertible 1.6 88hp help!

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chkto1000

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Hi all!

I am new in writing at this truely great forum, but I have been reading here a lot in the last couple of months, since I got my little Punto, so I would truely appreciate any help offered.

I wrote long becaue I wanted to describe my problems thorughly, so please be patient with me and read till the end.

1st question: can you please point me exactly to the location of the engine ECU? I am breaking my head and not sure where it is.

2nd question: does anyone have a PDF of the manual of this model (Garage / mechanic booj)? I got other books but I could not find anything fot this model.

and now comes the reason for my frustration and troubles since I got the car:

3rd question - big problem:

Since the beginning, the car would light the "check engine" light after driving a few km ans stay constant (the red light that looks like an injector) and after that it would hesitate (I guess this is the correct word: lose power and do "kangaroo jumping" - like there is some problem with electric current cutting, or fuel block). I could turn the motor off (simply while driving) and on again and it would go away for a few km, and than come again - and again restart.

What I noticed is that the car will not reach work-temperatue - worked cold (by looking at the dashboard). So I changed Thermostat and temperature sensor (attached to the Thermostat) - after that the temperature was working fine, but: I would start the car cold, and in the moment it reaches work-temperature the check engine light would come on and after a couple of minutes the problems would begin.

in the last 2 weeks it became worse: the kangaroo jumping is worse, the car will not rev (reach about 1500 rpm and will not drive: the accelerator will n ot react - just like there is a blocking on the gas and something is stopping it). by idle, mostly it idles fine and quiet (800 rpm) but the problems begin when driving, and then when trying to rev up also while standing, it will not be ok - no rev up. The car drives bad since the beginning of the ride.

I tried several things over the last 2 months:

I changed: oil & filter, spark plugs and Leads (cables), air filter, Lambda sensor (2 days ago), changed MAP sensor (I believe it is called that name: black square sensor with one small rubber pipe attached, located almost in the back of the engine compartment, behind and over the enging block. I also tried cleaning EGR valve. I tried several times ECU reset (after reading instructions: Battery cables disconnected, switch on/off, starting and letting warm up for about 15 minutes)

Plkease note the Lambda sensor: after changing it, I started from cold engine, drove about 10km beautifuly - very quiet, NO warning light and NO problems. The next day (yesterday) it was the same: about 10 km beautifuly, BUT - after stopping for 5 minutes I started driving again, and after a few hundred meters hell broke loose - it started again (but without warning light). After that it started again to drive in the worst situation with warning light comes on sometimes for a few seconds and dissapears. Will not go over 30mkh and will not rev up. Also, I heard small backfires coming from underneath.

This is it. Could any of you experts here please please help me? I am lost, but I really love this small convertible - would hate to give up on it because of something that in the end will be probably as easy as... :eek:

Thanks in advance!
 
You will find the engine ecu inside the car behind the centre console and directly beneath the heater matrix. You access it from the side by removing the plastic retaining nut which holds the carpet/trim on either side of the console and pulling it out of the way. To remove the ecu there are four bolts holding the cradle in position. Remove the front two and loosen the rear two, then pull the whole cradle forward to release it at the rear, then remove it to one side. If you do remove the ecu, it is work waterproofing it by putting it in a plastic bag before refitting it. This will protect it from any leaks from the heater matrix directly above.


I wonder whether your problem is related to a failing crank sensor as it appears to manifest itself when the engine has heated up. You can test this by removing the sensor and placing it in a pan of cold water while you measure the resistance. Gradually increase the temperature of the water until it is boiling and see if there is any change in the resistance reading. If it does change, then remove the sensor from the water and allow it to cool and see if the resistance is restored. If so, then you need a new sensor. If there is no change to the resistance the problem lies elsewhere.


I don't have a pdf of a manual, but if you can get hold of the Porter manual, that covers the 1.6 engine used in the Sporting and cabrio models.


I hope this assists you and wish you luck in resolving the issue.
 
renaultvation said:
You will find the engine ecu inside the car behind the centre console and directly beneath the heater matrix. You access it from the side by removing the plastic retaining nut which holds the carpet/trim on either side of the console and pulling it out of the way. To remove the ecu there are four bolts holding the cradle in position. Remove the front two and loosen the rear two, then pull the whole cradle forward to release it at the rear, then remove it to one side. If you do remove the ecu, it is work waterproofing it by putting it in a plastic bag before refitting it. This will protect it from any leaks from the heater matrix directly above.


I wonder whether your problem is related to a failing crank sensor as it appears to manifest itself when the engine has heated up. You can test this by removing the sensor and placing it in a pan of cold water while you measure the resistance. Gradually increase the temperature of the water until it is boiling and see if there is any change in the resistance reading. If it does change, then remove the sensor from the water and allow it to cool and see if the resistance is restored. If so, then you need a new sensor. If there is no change to the resistance the problem lies elsewhere.


I don't have a pdf of a manual, but if you can get hold of the Porter manual, that covers the 1.6 engine used in the Sporting and cabrio models.


I hope this assists you and wish you luck in resolving the issue.
Click to expand...

Thanks a bunch for your advice. I will definetely follow your instructions and hopefully find and take out the ECU - will do that during the weekend and update.

Regarding Crank sensor: I also read about it and perhaps you are right here. Is it also called cam sensor?
Could you perhaps direct me to where is the Crank sensor located and how to remove it?

Thanks again!
 
renaultvation said:
You will find the engine ecu inside the car behind the centre console and directly beneath the heater matrix. You access it from the side by removing the plastic retaining nut which holds the carpet/trim on either side of the console and pulling it out of the way. To remove the ecu there are four bolts holding the cradle in position. Remove the front two and loosen the rear two, then pull the whole cradle forward to release it at the rear, then remove it to one side. If you do remove the ecu, it is work waterproofing it by putting it in a plastic bag before refitting it. This will protect it from any leaks from the heater matrix directly above.


I wonder whether your problem is related to a failing crank sensor as it appears to manifest itself when the engine has heated up. You can test this by removing the sensor and placing it in a pan of cold water while you measure the resistance. Gradually increase the temperature of the water until it is boiling and see if there is any change in the resistance reading. If it does change, then remove the sensor from the water and allow it to cool and see if the resistance is restored. If so, then you need a new sensor. If there is no change to the resistance the problem lies elsewhere.


I don't have a pdf of a manual, but if you can get hold of the Porter manual, that covers the 1.6 engine used in the Sporting and cabrio models.


I hope this assists you and wish you luck in resolving the issue.
Click to expand...

Update:

Following your advice, I managed to find the ECU easily - thank you very much!

Regarding crank sensor - I am a bit confused with your instructions: do you mean that after the cool down, if the resistance returns to the value of the beginning (when the sensor was cold) it means that the sensor is bad, or I got it wrong? I am not sure I understood. Could you please clarify?

Other valued members that have other ideas, please post them.

thanks!
 
Yes, the crank sensor is also known as a cam sensor, but on the 1.6 Punto is mounted at the bottom of the engine. You will find it at the front of the engine at the bottom in front of the flywheel. It is held in by a single allen screw accessed from the front.


Yes, you do understand correctly. If the resistance changes when hot, but goes back to normal when cold it indicates a faulty sensor. If the resistance remains constant when hot and cold, then there is no fault with the sensor. This is why a car often starts when cold, but misfires when warm, or cuts out and won't start again until it cools down.
 
renaultvation said:
Yes, the crank sensor is also known as a cam sensor, but on the 1.6 Punto is mounted at the bottom of the engine. You will find it at the front of the engine at the bottom in front of the flywheel. It is held in by a single allen screw accessed from the front.


Yes, you do understand correctly. If the resistance changes when hot, but goes back to normal when cold it indicates a faulty sensor. If the resistance remains constant when hot and cold, then there is no fault with the sensor. This is why a car often starts when cold, but misfires when warm, or cuts out and won't start again until it cools down.
Click to expand...


All right, great. I located the sensor (left hand side, if you look at the car opposite you), bottom, almost on the flywheel but not touching it.

I will check the sensor and update.
 
renaultvation said:
Yes, the crank sensor is also known as a cam sensor, but on the 1.6 Punto is mounted at the bottom of the engine. You will find it at the front of the engine at the bottom in front of the flywheel. It is held in by a single allen screw accessed from the front.


Yes, you do understand correctly. If the resistance changes when hot, but goes back to normal when cold it indicates a faulty sensor. If the resistance remains constant when hot and cold, then there is no fault with the sensor. This is why a car often starts when cold, but misfires when warm, or cuts out and won't start again until it cools down.
Click to expand...

OK, quick update - i believe your suspect was right: testing the sensor gave me 515 when cold, 625 when water boiled, and gradually back to 515 again till cold.
So, do these numbers seem normal to a bad sensor, in your opinion? I really hope that this is the source of my current problems.
 
That doesn't seem too different to me, but perhaps someone else may be able to advise. When mine failed it changed from 523 when cold to 0 when hot, indicating a short circuit. This was obviously complete failure which caused the car to stall and not restart until it cooled down.
 
I've had the same problem in my 1.6 cabrio and it was the crank sensor that was faulty.

attachment.php




Check out my post:
https://www.fiatforum.com/punto/435762-1995-punto-cabriolet-elx-90-full-project-big.html

I replaced almost everything from sensor to bad wires.
You could see how to replace the crank sensor there also.
 
Last edited:
chesh said:
I've had the same problem in my 1.6 cabrio and it was the crank sensor that was faulty.

attachment.php




Check out my post:
https://www.fiatforum.com/punto/435762-1995-punto-cabriolet-elx-90-full-project-big.html

I replaced almost everything from sensor to bad wires.
You could see how to replace the crank sensor there also.[/QUOTE


שלום שלום! אני גם ישראלי כמוך, ואני פשוט גר במקום אחר - תמיד טוב לשמוע עצות מישראלי בעל תושיה... :) אני אמשיך לכתוב באנגלית לטובת הפורום.

Thanks for the tip! I have already read your post before and this is why I also suspected this sensor. You did a great (and probalbly expensive...) job on your beautiful car.

Do you still have this nice car (your post is from 2016)?

So, you think this sensor is the blame? before you installed it, did you check it, as mentioned here, or you simply changed it?
Click to expand...
 
chkto1000 said:
שלום שלום! אני גם ישראלי כמוך, ואני פשוט גר במקום אחר - תמיד טוב לשמוע עצות מישראלי בעל תושיה... :) אני אמשיך לכתוב באנגלית לטובת הפורום.

(y)
Click to expand...

Yes I still owe the car.
There is not really a way to check it, unless you have a scanner which connects to the ODB port (only old fiat garage has the "Fiat Examiner" which can connect to this ECU to read errors).

The crank sensors are very sensitive on puntos, problem starts when you try playing with it's cable.

On mine the cable shield was torn as you could see in the picture.
I owe puntos for around 10 years and I know it's symptoms.

*Jerking when driving/starting issues are most likely from the crank sensor.
*Engine cuts off immediately is either EGR or special speed sensor that is located on the gearbox.
*Power loss can be either spark plugs, ignition wires, timing belt not set up correctly.
*Black smoke can be a bad MAP sensor.

There is a long list of common problems on Autodata, I'll try to take a picture from the program when I get home.

Other than that, I always prefer changing 20 years old sensors to new ones (it cost peanuts on ebay).
 
Last edited:
chesh said:
Yes I still owe the car.
There is not really a way to check it, unless you have a scanner which connects to the ODB port (only old fiat garage has the "Fiat Examiner" which can connect to this ECU to read errors).

The crank sensors are very sensitive on puntos, problem starts when you try playing with it's cable.

On mine the cable shield was torn as you could see in the picture.
I owe puntos for around 10 years and I know it's symptoms.

*Jerking when driving/starting issues are most likely from the crank sensor.
*Engine cuts off immediately is either EGR or special speed sensor that is located on the gearbox.
*Power loss can be either spark plugs, ignition wires, timing belt not set up correctly.
*Black smoke can be a bad MAP sensor.

There is a long list of common problems on Autodata, I'll try to take a picture from the program when I get home.

Other than that, always prefer changing 20 years old sensors to new ones (it cost peanuts on ebay).
Click to expand...


OK, I will just have to try it and hope for the good. I am ordering the sensor now, and will update after it is arrived and installed.

Myself I am also a big Punto fan - nothing like these small Italians - and this cabrio that I got now is so sweet, that it is just a pity not to be able to make it go well again. :bang:

Do put the Autodata picture - it is great info.

Thanks! :worship:
 
Known issues according Autodata
 

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Update: I installed the sensor but unfortunately no luck - the same.

I took her for a drive, in this bad condition and noticed the following: The situation is that the gas pedal is not responding - it is like it stays around 1000 rpm and not realy reacting. Why not realy? becauese sometimes it would jerk to 2000, but go down quickly again. But mostly it just stays on 1000 and not reacting. The ride is very bumpy and by reaching 4th gear I can go 20-30 kmh WHEN THE GAS PEDAL IS PRESSED VERY LIGHT. If I press the gas harder it would choke - like when the engine is flooded - and almost dies (sometimes it died). I did also rev experiement while standing and pulling the gas cable under the bonnet and noticed: it wil not react and after 2-3 pulls if I hold the cable pulled it would "choke" as flooded, and a strong knock from the engine blocks comes out (the engine will jitter at that second).

Another thing that I noticed is now it is also erratic by idling: idles between 800-900 rpm (instead of the steady 850 rpm), and after a few seconds gets down to about 500 rpm quick, and after a second goes back up again.

I don't know if there is a connection here, but the battery terminals were disconnected for around 24 hours prior me installing the sensor. Computer programming?

Do you have perhaps any more ideas what is going on? Of course, anyone? please?

Looking forward to your reply.
 
Is the injector light still on?

When did you change the spark plugs and what brand is it?
Please take them out and take a picture, from what you describe, it should be all black.

Also, check the Coil plug. is it attached correctly?
+ Check the blue/black coolant temp sensor, which is located at the thermostat hosing.
It sends temp to the ECU, if it's faulty, ECU thinks the car is always cold and will flood the engine.
 
chesh said:
Is the injector light still on?

When did you change the spark plugs and what brand is it?
Please take them out and take a picture, from what you describe, it should be all black.

Also, check the Coil plug. is it attached correctly?
+ Check the blue/black coolant temp sensor, which is located at the thermostat hosing.
It sends temp to the ECU, if it's faulty, ECU thinks the car is always cold and will flood the engine.
Click to expand...

OK, will do and inform.
The plugs are NGK and I've changed a few hundreds KM ago. I will take them out.

Regarding the temp sensor: I was also suspecting it but don't know what should I do: I changed Thermostat and this sensor - so, it's new. After changing these parts, the temperature gauge on the dashboard shows that the temp is rising, and it's reaching work temeprature when it shows QUARTER. It stays in this level when I drive (country roads no traffic) and would climb only when i stand long time untill the fan kicks in. I am not sure if it suppose to be like that, and whther it's just a gauge which is not important.
 
I would also check the temp with a laser gun if you suspect the gauge.
I live in a hot place (around 30-40c in this time of year), fan kicks in exactly when half of the gauge. and when driving outside it can be a little bit below that but no quarter.

I use genuine and old stock parts, thermostat should be 87-92 and also the temp sensor on the radiator.

But, that doesn't seem related to your problem.
I would also check the fuel filter and to see that there is no blockage in that system (fuel pressure test).
There is also fuel regulator on the manifold, check it's vacuum pipe that is attached from it to the manifold.
Is the engine working ok on idle? if it is, try to remove each HT lead, might be also be a faulty coil unit or HT leads were connected the wrong way.

If the injector light still stays on, there is no really a way to check it but to replace parts or to visit a fiat garage that still owe the tools to connect the OBD port.
 
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