General Non start

[judderbar]

?

The video demonstrates what an injector sounds like which is something the OP can check for himself using the methods you described.

Does he have a spark?

 

[koalar]

?

The video demonstrates what an injector sounds like which is something the OP can check for himself using the methods you described.

Does he have a spark?

Yes its always run by spraying easy start into the inlet

It's not the crank sensor

Yes you can listen to the injectors

Wouldn't explain why the misfire follows the coil when they were swapped

 

[PuntoHowTo]

Yes its always run by spraying easy start into the inlet

Where does it say that ? I also see that the problem is not consistent with the car sometimes running sometimes not.

It's not the crank sensor

I’m not sure that has been conclusively ruled out, but assuming that we “always” have a spark then the next avenue of exploration is fuelling.

Coils on these are common issues but if it “always” runs on easy start then it should “always” run on petrol assuming there is no fueling fault, so the misfire is likely a secondary issue.

Until the OP comes back with the slew of questions you’ve thrown out above, there really isn’t much more to talk about.

 

[koalar]

Where does it say that ? I also see that the problem is not consistent with the car sometimes running sometimes not.


I’m not sure that has been conclusively ruled out, but assuming that we “always” have a spark then the next avenue of exploration is fuelling.

Coils on these are common issues but if it “always” runs on easy start then it should “always” run on petrol assuming there is no fueling fault, so the misfire is likely a secondary issue.

Until the OP comes back with the slew of questions you’ve thrown out above, there really isn’t much more to talk about.

Post 1
Sentence one

"Hi all i have a mk 2 punto 1.2 8 v turns over but won’t start but will run on easy start,"

If at this early stage a teaspoon of petrol added to each cylinder and retested we would know by now if it was a fuel problem or not, unfortunately easy start isn't conclusive as it's more volatile

But the crank sensor, is one of the last places I would be looking

Has to have a signal from the crank sensor to fire the ignition coils at the correct time to run

Unless I am looking at this totally wrong

I only got involved because, in my opinion the thread was going in the wrong direction

Yet it keeps coming back to the crank sensor

Maybe I'll end up with egg on my face, time will tell.

They have a scantool just read the data is the obvious step if the crank sensor is suspected

There's no need to hook up a sound card or anything complicated, no LEDs, just read the RPM, they also probably have a rev counter as well

Simple things like looking at the plugs, seeing if the plugs are getting wet with fuel, looking if oil is on the MAP haven't been done

I never said it's the coils, I said the misfire recorded by the ECU followed the coil swap over, (cylinder 3 , changed to cylinder 1) they may have swapped the HT leads also

I also stated that the constant misfire they have at idle is important to identify and fix, if you carry on as the original poster has for sometime, a) it will lead the cylinder wear as the unburnt petrol wipes the oil away B) the high voltage will eventually burrow through the coil and can and does blow the the ECU drives C) the unburnt fuel will eventually melt and plug the catalytic converter, it should not be ignored

Personally I doubt the misfire is the only problem

Flooded, compression, timing, fueling out, fuel pump, plugs, plugged cat, and many more

When it was running I fix the obvious fault first, there's 4x most things leads, injectors, plugs and two coils, if by swapping parts over the misfire stays with the same cylinder then a compression test would be needed

 

[PuntoHowTo]

Post 1
Sentence one

"Hi all i have a mk 2 punto 1.2 8 v turns over but won’t start but will run on easy start,"

If at this early stage a teaspoon of petrol added to each cylinder and retested we would know by now if it was a fuel problem or not, unfortunately easy start isn't conclusive as it's more volatile

But the crank sensor, is one of the last places I would be looking

Has to have a signal from the crank sensor to fire the ignition coils at the correct time to run

Unless I am looking at this totally wrong

I only got involved because, in my opinion the thread was going in the wrong direction

Yet it keeps coming back to the crank sensor

Maybe I'll end up with egg on my face, time will tell.

They have a scantool just read the data is the obvious step if the crank sensor is suspected

There's no need to hook up a sound card or anything complicated, no LEDs, just read the RPM, they also probably have a rev counter as well

Simple things like looking at the plugs, seeing if the plugs are getting wet with fuel, looking if oil is on the MAP haven't been done

I never said it's the coils, I said the misfire recorded by the ECU followed the coil swap over, (cylinder 3 , changed to cylinder 1) they may have swapped the HT leads also

I also stated that the constant misfire they have at idle is important to identify and fix, if you carry on as the original poster has for sometime, a) it will lead the cylinder wear as the unburnt petrol wipes the oil away B) the high voltage will eventually burrow through the coil and can and does blow the the ECU drives C) the unburnt fuel will eventually melt and plug the catalytic converter, it should not be ignored

Personally I doubt the misfire is the only problem

Flooded, compression, timing, fueling out, fuel pump, plugs, plugged cat, and many more

When it was running I fix the obvious fault first, there's 4x most things leads, injectors, plugs and two coils, if by swapping parts over the misfire stays with the same cylinder then a compression test would be needed

You maybe right in it not having anything to do with the crank sensor but the intermittent nature of this fault in my view is pointing to a sensor, rather than something more mechanical.

One other thing I did consider is the fuel pressure regulator. I replaced this on my Punto cabrio as the plastics had become brittle and were falling apart. If the pressure regulator has failed then you could see fueling issues, but I would have thought that would throw up a code.

Not all puntos had RPM gauges a lot of the lower spec models came without.

 

[judderbar]

You maybe right in it not having anything to do with the crank sensor but the intermittent nature of this fault in my view is pointing to a sensor, rather than something more mechanical.

One other thing I did consider is the fuel pressure regulator. I replaced this on my Punto cabrio as the plastics had become brittle and were falling apart. If the pressure regulator has failed then you could see fueling issues, but I would have thought that would throw up a code.

Not all puntos had RPM gauges a lot of the lower spec models came without.

The designed 3 Bar fuel pressure is created by the continually running pump. Even though the pump runs for 5 seconds at ignition on it is not measuring a pressure and then stopping.

 

[koalar]

The designed 3 Bar fuel pressure is created by the continually running pump. Even though the pump runs for 5 seconds at ignition on it is not measuring a pressure and then stopping.

Correct at this year, the pressure diaphragm was built in to the top of the fuel pump

I never know one fail, the pump motors occasionally fail by not spinning, yes they should spin constantly while cranking and engine running as well as a couple of seconds at ignition on

Unfortunately we missed the opportunity to diagnose the problem back in november


Hopefully the original poster will comeback with some feedback and we can progress forwards

 

[curly43]

Ok latest is cleaned out fuel tank ,filled with new fuel and she starts but has bad misfire not drivable still trying to fix.any suggestions would be great fully appreciated.

 

[judderbar]

Ok latest is cleaned out fuel tank ,filled with new fuel and she starts but has bad misfire not drivable still trying to fix.any suggestions would be great fully appreciated.

Codes?

start the car and then disconnect each spark plug, listen to the engine and then reconnect and do the next plug , to identify which cylinders are not working correctly.

 

[curly43]

Did the above but each cylinder has the same note/ rpm change,did it with plug leads at both ends then at the injector leads, still the same , so can not verify what cylinder or cylinders the misfire is on as they all are the same.

Codes?

start the car and then disconnect each spark plug, listen to the engine and then reconnect and do the next plug , to identify which cylinders are not working correctly.

 

[curly43]

Did the above but each cylinder has the same note/ rpm change,did it with plug leads at both ends then at the injector leads, still the same , so can not verify what cylinder or cylinders the misfire is on as they all are the same.

Codes: the only codes that keep come up are the dreaded u1601 & u1600

 

[judderbar]

Codes: the only codes that keep come up are the dreaded u1601 & u1600

On my car I can remove the injector rail from the intake manifold and arrange everything so I can see the injectors spraying/misting/atomising into a baking tray lined with tissue paper so i can see if the injectors spray rather than dribble. While doing this you can also be sure the injectors fire in a regular sequence.

It is a good idea to remove all the electrical connectors from the ecu and fusebox and pretty well everything else and reconnect them a few times.

 

[curly43]

On my car I can remove the injector rail from the intake manifold and arrange everything so I can see the injectors spraying/misting/atomising into a baking tray lined with tissue paper so i can see if the injectors spray rather than dribble. While doing this you can also be sure the injectors fire in a regular sequence.

It is a good idea to remove all the electrical connectors from the ecu and fusebox and pretty well everything else and reconnect them a few times.

Yes did the injector test as you described all good + put another fuel rail and injectors in , still multi misfiring.

 

[judderbar]

Yes did the injector test as you described all good + put another fuel rail and injectors in , still multi misfiring.

Earlier I suggested you test the crank sensor. In my opinion there is no waste in replacing it if you cannot test it because these sensor have an internal magnet which most likely does not last forever. In any case all the crud around the sensor should be cleaned off as most likely the crud contains material that will alter the magnetic field. You have not reported to us if you have an RPM or tachometer. It should operate smoothly at about 250rpm when cranking. What about live data from a scanner?

If you play around with small amounts of easy start is there any point you can get the engine to run more smoothly? I never used easy start but even a rag with some petrol on it will get a car to run quite well briefly. Some easy start on the rag will enable you to test if tiny amounts of extra fuel make a difference.

 

[curly43]

Earlier I suggested you test the crank sensor. In my opinion there is no waste in replacing it if you cannot test it because these sensor have an internal magnet which most likely does not last forever. In any case all the crud around the sensor should be cleaned off as most likely the crud contains material that will alter the magnetic field. You have not reported to us if you have an RPM or tachometer. It should operate smoothly at about 250rpm when cranking. What about live data from a scanner?

If you play around with small amounts of easy start is there any point you can get the engine to run more smoothly? I never used easy start but even a rag with some petrol on it will get a car to run quite well briefly. Some easy start on the rag will enable you to test if tiny amounts of extra fuel make a difference.

Fitted a new crank sensor still multi misfiring. Yes has rev counter,

 

[GrandePunto PL]

Maybe put those codes to Google again. For me (search results are a bit personalized) it says also "ECU failure", not only bad power (low voltage) to the ECU or communication to other modules (results tell also to check a Body Computer, it can spoil the CAN lines).

Use proper OBD2 interface and FES or MES software. There's more options (including tests: injectors, coils, other stuff).

Check the fuel pressure.

 

[curly43]

Fuel pressure is 3 bar and a new Bosch fuel pump.

 

[PuntoHowTo]

Use proper OBD2 interface and FES or MES software. There's more options (including tests: injectors, coils, other stuff).

This ^^^^


At this point I would be doing a compression test. If you have a spark and fuel, and it is trying to fire, then its time to crack out the compression tester and look at the timing.

 

[curly43]

This ^^^^


At this point I would be doing a compression test. If you have a spark and fuel, and it is trying to fire, then its time to crack out the compression tester and look at the timing.

Timing was 1 tooth out from previous cam belt change 500 miles ago, now spot on double checked. Did compression test 1: 212. 2:180. 3: 220. 4:200. She starts now as stated after cleaning out fuel tank but still multi misfiring.

 

[varesecrazy]

. Did compression test 1: 212. 2:180. 3: 220. 4:200. She starts now as stated after cleaning out fuel tank but still multi misfiring.

Did you compare dry, then wet?