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Old 18th February 2015, 13:16   #61
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Default Re: FIAT Adventure issues

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Originally Posted by mahadev_kc View Post

7. After 2 days, I see the same problem of misfiring, car shuddering, no engine power with rpm raising in any gear. This was with new ignition coil put in. So, thought this could be because of battery gone weak (as it was 4.5 years old and when engine is cranked, the battery voltage was dropping to 9V instead of 11v as in a healthy battery), so changed to a new battery. And driven the car for around 10kms. Here it is felt as if it is a new car, with everything proper.

8. After driving around 10 kms, the engine started misfiring again. So a very serious problem.
when you mentioned you recorded 9v instead of 11v when the engine is cranked, I hope you mean when the starter motor is operated.
I hope you checked the output voltage while the engine idles after fitting the new battery and the reading should be somewhere between 13.6 to 14volts.
A quick way to test the alternator would be to start the car when its cooled down properly (assuming it runs fine when cold) and turn on the lights wipers and the AC and put on a good electrical load to the alternator. If the engine misfires that time even before it warms up, then have the alternator checked for proper amperage. It could be weak.

And as you mentioned some rats menacing with the cars wiring and connections to sensors and that too related to the temp sensor, its worth a look to check its health. And from your earlier posts I'm pretty sure you know your way around your car quite well, I presume you've already done that.
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Old 18th February 2015, 14:20   #62
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Default Re: FIAT Adventure issues

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I hope you checked the output voltage while the engine idles after fitting the new battery and the reading should be somewhere between 13.6 to 14volts.
Yep. It was charging the battery and the voltage was staying at 13.92v

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Originally Posted by msaudf View Post
A quick way to test the alternator would be to start the car when its cooled down properly (assuming it runs fine when cold) and turn on the lights wipers and the AC and put on a good electrical load to the alternator. If the engine misfires that time even before it warms up, then have the alternator checked for proper amperage. It could be weak.
I could not do this, as during startup only, the engine starts misfiring, meaning whole vehicle shudders and shakes, and rpm stays almost around 400-500.
Will try to do when it is cold to check the condition of the alternator.

Quote:
Originally Posted by msaudf View Post
And as you mentioned some rats menacing with the cars wiring and connections to sensors and that too related to the temp sensor, its worth a look to check its health. And from your earlier posts I'm pretty sure you know your way around your car quite well, I presume you've already done that.
I'm yet to do. The mechanics who earlier looked into this, never said any other wires was eaten/destroyed by rats except the one that is connected to coolant temp sensor. Will check over the week-end.

Thanks for your support.
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Old 18th February 2015, 16:34   #63
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Default Re: FIAT Adventure issues

1. RPM shoots up to 3000 - did you check if the clutch pedal is fouling with the accelerator cable?

2. RPM hovers around 200-500 - not related to ignition coil, IMO. As you mentioned, this happens when the car is warmed up. A weak fuel pump / weak wiring around the fuel pump may cause this. The fuel pump tends to foul when warm, that is why it stays submerged in the petrol tank - please check this out as well - you can access it by removing the rear seat.

3.
Quote:
Cause for shaky rpm.
a. weak/leaky vacuum hose
b. Failing ign coil
c. Incorrect timing
d. Weak crank position sensor.

If the engine missing pull between 1200~2500 rpm then definitely O2 sensor.
I have shaky rpm in my GTX and later I found air is leaking from the throttle body IAC valve. Since its a press fit one some how it developed leak on the sides. I sealed with araldite and now the rpm is rock steady.
Also test the idle by disconnecting O2 sensor socket. If the idle stabilizes after dismantling needs sensor replacement.
Weak crank sensor is known for shaky rpm. Make sure the sensor and phonic wheel gap is atleast 0.8mm
Replace sparkplugs with NGK BKR5E and the plug gap is 0.8mm.
i have changed the spark plugs (earlier running with Palio 1.2 Champion RC8BYC Lancia twin spark Plugs - my fault) with Champion RC10YCC Hyundai OE plugs (same as for Palio 1.6 - check Owner's Manual Page: 132).

Last edited by planet_rocker : 18th February 2015 at 16:46.
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Old 18th February 2015, 17:44   #64
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Default Re: FIAT Adventure issues

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1. RPM shoots up to 3000 - did you check if the clutch pedal is fouling with the accelerator cable?
Yes we did check this. When the clutch is pressed, there is not change in the accelerator cable pull-up in the throttle body.

Thanks,
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Old 19th February 2015, 14:15   #65
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Default Re: FIAT Adventure issues

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Originally Posted by mahadev_kc View Post
Also, the rats chew some part of this wire. This wire is connected to a sensor that is connected to a coolant tube. I think it may be the temperature sensor, though I'm not sure. Next time, I will click a photo of it and will post here.
Attached photo shows the circled part where in these wires were chewed, but I see that only surface is chewed and no cuts in wires. I'm thinking this could be temperature sensor connector.

With all of the above issues, does this cause any thing of the above?

In addition to this, the injector light on dashboard never comes ON during the starting of the car. May be the LED might have gone bad in the instrument cluster.
Attached Thumbnails
FIAT Adventure issues-img_20150218_225513.jpg  


Last edited by mahadev_kc : 19th February 2015 at 14:17.
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Old 22nd February 2015, 23:25   #66
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Default Re: FIAT Adventure issues

Hello All,

A small update:

Went to Venkatesh (Bangalore, Gowri Automobiles) for checking with the engine missing. He checked the compression of each cylinder and found to be in the range of 120. Next was to check any of the spark plug is not getting current. During this check, we found that current was not passing on terminals 2 and 3.
Then as planet_rocker said and from some other forum, we decided to disconnect the o2 sensor. voila, now all cylinders are getting fired and no missing at all.
With this note, we went to Vecto motors to check on the analyser. It was 14 kms and engine behaved normally. There were errors wrt stepper motor in throttle body, but nothing significant.

People there suggested to check with different ECU, as ECU may be malfunctioning. As suggested in other forums, we did a reset and reset of adaptable parameters through analyser. With this, we travelled back from Vecto to Venkatesh's place. During this time, we find the engine was misfiring.

Then Venkatesth suggested to leave the car there and we will try to find an alternate ECU to check with.

Today he arranged a different ECU and connected to the car. Now I do not see any misfires happening, and the idle rpm is rock steady, no rising of RPM when the clutch is pressed and all these complaints are gone. We have put the araldite over the gaps between the IAC volve and throttle body as suggested by planet_rocker and in other forums.

Now I've to drive for a week with the borrowed ECU and if everything is fine, will have to change to new ECU or buy the borrowed ECU. Keeping fingers crossed.

All in all, only change in ECU and plugging the air leakage near IAC valve and throttle body seems to solved the issue.

Thanks everyone, now life is back. will update further going...
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Old 4th March 2015, 23:03   #67
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Default Re: FIAT Adventure issues

Update to this problem is that the ECU was changed. Then from last 2 weeks, I've not observed any issues of missing, irregular rpm, rpm raising when the clutch is pressed.

Thanks a lot for your help.
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Old 7th June 2016, 11:19   #68
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Default Re: FIAT Adventure issues

Bumping up the stagnant thread and also Long Post Warning

The infamous Palio RPM issue finally has caught up with me.

Car - Palio GTX 1.6, 2003, 90,000 KMS

2 weeks ago when driving in heavy rains and virtual rivers on the road, a bus decided to overtake me from the left and sent a tsunami towards my car. The wave almost overran the bonnet and immediately there was light smoke from the engine bay. My house was just 2 KMS away and since it was pouring heavily, I decided to drive home and check. When I reach the parking, I could hear a hissing/grinding noise from the alternator area. My heart sank immediately and I decided to check next day. There was loud hissing sound from the alternator and belt noise from the alternator.

Since the mechanic was busy, took the car to him after couple of days. Alternator bearing and rectifier was replaced, alternator belt and tensioner bearing also needs replacement but was not in stock.

Got the car after 2 days and everything was OK except a small hissing/belt noise from the tensioner bearing. I knew it would be there since tensioner and belt needs to be replaced.

After the alternator work was done, I am facing the RPM issue.

1. On day 1, the RPM would randomly fall to zero whenever I pressed the clutch to down shift but the car didn’t stall and would recover with in a second.
2. Couple of days later, the RPM regularly fell to zero whenever I pressed the clutch to down shift when the car was doing below 20-30 KMPH.
3. Then, the RPM regularly fell to zero whenever I pressed the clutch to down shift when the car was doing below 20-30 KMPH and the car would stall
4. Then, the speed limit increased to 40-50 KMPH and would always stall if I came below 30 KMPH.
5. When idling, the RPM started to fall to zero and the entire car vibrates/misfires heavily and then suddenly recovers but doesn’t stall.
6. This vibration/misfire has increased and feels like the engine will falls any moment now but car stall now
7. Now the RPM falls to zero if when the car is cruising at 60-70 KMPH when I take my foot off from the accelerator.
8. Then yesterday there was huge smoke from the exhaust as if it’s a diesel engine.
9. The car now is not safe to drive at all and is causing me a lot issues.

Yesterday whole day spend time in the garage with the mechanics. There was another palio 1.6 with the mechanic, so tried below stunts –

1. Checked and replaced the spark plugs – Issue not solved
2. Checked the spark plug cables/wires for spark one by one and dint find any issues - Issue not solved
3. Cleaned the throttle body thoroughly and check for leak – Issue not solved
4. Cleaned the MAF sensor - Issue not solved
5. Replaced the RPM Sensor with a spare one - Issue not solved
6. Swapped the Spark Plug cables/wires from another car - Issue not solved
7. Swapped the ignition coil from another car - Issue not solved
8. Swapped the throttle body from another car - Issue not solved
9. Connect the scanner, there is no errors as well.

I think next I need to change the ECU and check. But it’s not easy to get hold of a spare ECU. I am desperately looking for a solution now.

Some new things we found out when doing the above –

1. Spark plug had considerably blackened and then we cleaned it and put to back. Took a drive for 2 KMS and then when we opened the spark had blackened a lot.
2. The car runs smoothly for the first 2-3 KMS or 5 Mins, only then all the issues starts.
3. There is no warning/injector light on the dashboard at all.

Any Suggestion is more than welcome -

Regards

Last edited by chandrda : 7th June 2016 at 11:20. Reason: Corrected
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Old 9th June 2016, 01:14   #69
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Default Re: FIAT Adventure issues

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Originally Posted by chandrda View Post
Some new things we found out when doing the above

1. Spark plug had considerably blackened and then we cleaned it and put to back. Took a drive for 2 KMS and then when we opened the spark had blackened a lot.
Few questions form my end :

Is just one plug turning black or all 4?

When was the O2 sensor changed last?

Any rat attacks in the engine bay in the past/current?

Blackened spark plugs are the sign of incomplete combustion. However if its turning black within 2KM drive then something is probably wrong with the injectors. They are mostly dumping excess fuel into the manifold. Even when you say the RPM drops suddenly, its probably because the injectors at that point dump a LOT of fuel and the engine doesn't get enough air to burn it/plugs get overwhelmed. If any one cylinder spark plug is getting black, the injectors on that cylinder is giving problems. If not, I suspect the wiring between the ECU and injectors to be suspect. Get the mechanic to go through the whole wiring loom in the engine bay with a fine toothed comb.

What does the O2 sensor say when its connected to the scanner? Is it stuck on Rich or does it keep varying between lean and rich? The Palio ECU does not give an error if the O2 sensor is defunct.

If the injectors and wiring are fine then the ECU probably is culprit.
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Old 13th June 2016, 09:36   #70
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Default Re: FIAT Adventure issues

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Originally Posted by SunnyBoi View Post
Few questions form my end :

Is just one plug turning black or all 4?

When was the O2 sensor changed last?

Any rat attacks in the engine bay in the past/current?

Blackened spark plugs are the sign of incomplete combustion. However if its turning black within 2KM drive then something is probably wrong with the injectors. They are mostly dumping excess fuel into the manifold. Even when you say the RPM drops suddenly, its probably because the injectors at that point dump a LOT of fuel and the engine doesn't get enough air to burn it/plugs get overwhelmed. If any one cylinder spark plug is getting black, the injectors on that cylinder is giving problems. If not, I suspect the wiring between the ECU and injectors to be suspect. Get the mechanic to go through the whole wiring loom in the engine bay with a fine toothed comb.

What does the O2 sensor say when its connected to the scanner? Is it stuck on Rich or does it keep varying between lean and rich? The Palio ECU does not give an error if the O2 sensor is defunct.

If the injectors and wiring are fine then the ECU probably is culprit.
Thanks for the indicating it right SunnyBoi.

It was infact the O2 sensor which was defunct now. Since I couldn't go to the showroom again for the scanner, just swapped the O2 sensor from another car and it started working well.

So replaced the O2 sensor and 4 spark plugs along with it. Now the car is working perfectly well.

Somehow the showroom guys failed to locate the O2 sensor failure when they had connected the scanner.

Regards
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