Technical Petrol Injector question

[Neil Ives]

Hello,
I have a second generation 61 reg Panda 1.2 petrol. I'm having what appears to be one cylinder not firing for a while especially after a hot restart. Car usually goes well when driving but can go to only three when pulling up a hill etc. I've changed the spark plugs which made no difference. Yesterday I took the injectors out and cleaned them with brake cleaner and compressed air. Possibly a slight improvement but still not right. Before I invest in a new set of injectors, (££££!) I'd like to be sure that that's what the problem is. Will you let me have your thoughts on the problem please.
Many thanks for any replies.
Neil

 

[jackwhoo]

Strongly recommend multiecuscan diagnostic software.
Free to download and a suitable cable to connect to your car very cheap.

You can download it , launch it , select your fiat model , click simulate and have look at what it can do.

Read and clear fault codes and loads more.
Lots of people on this forum use it.

I would say it's a good next step to try on your car. There may be a fault code that hasn't caused the check engine light to come on.

Good luck.
Jack

 

[Neil Ives]

Strongly recommend multiecuscan diagnostic software.
Free to download and a suitable cable to connect to your car very cheap.

You can download it , launch it , select your fiat model , click simulate and have look at what it can do.

Read and clear fault codes and loads more.
Lots of people on this forum use it.

I would say it's a good next step to try on your car. There may be a fault code that hasn't caused the check engine light to come on.

Good luck.
Jack

Thanks but I don't think the £120 price tag would be worth it for me. I could take it to a garage and get them to diagnose it with their gizmo I guess.

Still hoping to hear if the symptoms are typical of a failing injector.

 

[jackwhoo]

It's free unless you want to use extra features free free free

 

[jackwhoo]

Thanks but I don't think the £120 price tag would be worth it for me. I could take it to a garage and get them to diagnose it with their gizmo I guess.

Still hoping to hear if the symptoms are typical of a failing injector.

It's free unless you want to pay and unlock some of the additional features

 

[jackwhoo]

The lead I use was around £6

The problem with your car could be so many things it's not economical to change parts hoping to find the fault.
Apart from the spark plugs which you have already changed.

 

[portland_bill]

As said above, MES is the best way forward. Not sure where you get £120 from, I believe it is €50 for a licence for a fully working version. However, the free version will do lots of diagnosis, but not clear faults. So with the free download and a set of cables, you are away. The full version can also be used plugged in as a monitor while running. That may show up the fault while it is happening.

A common problem on Punto Mk2 is a misfire from coil failure, or connections to the coils needing cleaning or tightening. The connector to the ECU sometimes gets a loose pin.
If you can determine which cylinder is misfiring, swap the coils and see if the problem moves. Plug leads also need changing occasionally, as they will start to break down.

Injectors are very unlikely. Strange you have fixed on these, which must cost more than £120 to replace, so spend some money on MES instead.

Check connections of ECU and coils.
Swap coils if misfiring cylinder is known.
Carry out a compression test.
Consider new plug leads.

 

[Neil Ives]

As said above, MES is the best way forward. Not sure where you get £120 from, I believe it is €50 for a licence for a fully working version. However, the free version will do lots of diagnosis, but not clear faults. So with the free download and a set of cables, you are away. The full version can also be used plugged in as a monitor while running. That may show up the fault while it is happening.

A common problem on Punto Mk2 is a misfire from coil failure, or connections to the coils needing cleaning or tightening. The connector to the ECU sometimes gets a loose pin.
If you can determine which cylinder is misfiring, swap the coils and see if the problem moves. Plug leads also need changing occasionally, as they will start to break down.

Injectors are very unlikely. Strange you have fixed on these, which must cost more than £120 to replace, so spend some money on MES instead.

Check connections of ECU and coils.
Swap coils if misfiring cylinder is known.
Carry out a compression test.
Consider new plug leads.

Thanks Portland Bill; more info is good. As an ex mechanic, (Ford Anglia and Morris Oxford days) my first thought was spark plug faulty so I changed them. Still misfiring; could it be injectors? Petrol cars didn't have injectors when I were a lad! :worship:
The thing is the car still goes as well as ever when it's ok.

Thanks jackwhoo: Where did you get the lead?
Where did you get the free version of the software?
On the GenDan website they want £120 for the kit.

 

[Neil Ives]

OK, I've found a Multiecuscan site with the software free.

 

[jackwhoo]

Google multiecuscan
Select multiecuscan.net
Download free version , it is legitimate.
I cannot remember where I bought lead , think Amazon.
I went for the vagcom lead , there are options which are explained on the MES site.
If any other member can suggest a good lead retailer please do so.
The free version I have does clear Fault codes.

Don't fixate on an injector , problem could be many things.
If MES does flag which cylinder missing , you can then swap a component with another cylinder until the misfire moves to try and identify what has failed.
It's not a magical fix though sometimes more investigation is required.

Have deliberately chosen not to list what the problem could be because it really could be almost anything.

Portlandbill has already posted what I would suggest as a starting point.

 

[jackwhoo]

worthwhile check is the HT leads and coils because symptoms are classic weak spark failing under load.
Electronic ignition systems are a lot higher voltage than contact breaker systems, Do Not touch with engine running if you have or have had heart problems.

 

[g8rpi]

Thanks Portland Bill; more info is good. As an ex mechanic, (Ford Anglia and Morris Oxford days) my first thought was spark plug faulty so I changed them. Still misfiring; could it be injectors? Petrol cars didn't have injectors when I were a lad! :worship:
The thing is the car still goes as well as ever when it's ok.

Thanks jackwhoo: Where did you get the lead?
Where did you get the free version of the software?
On the GenDan website they want £120 for the kit.

Hi,
This lead set
http://www.ebay.co.uk/itm/162524569889
will do all modern Fiats for £27. You can get much cheaper interfaces but they tend to have a design fault (terminating resistor) that stops connection to some modules. I've bought the item linked above and it works OK.
Registration of MES www.multiecuscan.net is only 50 Euros. Please don't use a "cracked" copy. If people do this the author (who is a member of Fiat Forum) will have no reason to provide updates or support and we will all suffer. Even if you only intend to do basic servicing you will need MES or similar. Registration covers updates for a year, but you will only have to pay again if you get a much newer car.

Robert G8RPI.

 

[Neil Ives]

Hi,
This lead set
http://www.ebay.co.uk/itm/162524569889
will do all modern Fiats for £27. You can get much cheaper interfaces but they tend to have a design fault (terminating resistor) that stops connection to some modules. I've bought the item linked above and it works OK.
Registration of MES www.multiecuscan.net is only 50 Euros. Please don't use a "cracked" copy. If people do this the author (who is a member of Fiat Forum) will have no reason to provide updates or support and we will all suffer. Even if you only intend to do basic servicing you will need MES or similar. Registration covers updates for a year, but you will only have to pay again if you get a much newer car.

Robert G8RPI.

Ok folks, I've ordered the leads shown in g8rpi's post. Should be here later in the week. I've downloaded the free version of the software. I'll have to set my desktop PC out on the bike box in front of the car as I have no garage! I just hope this shows up the problem.
I'm pleased to read that the fault is unlikely to be injectors. At the last service the mechanic changed one of the injectors because he said it was leaking petrol. When I cleaned them last week I noticed that the new one has only one nozzle, the others have six; is that likely to be significant?

 

[g8rpi]

Ok folks, I've ordered the leads shown in g8rpi's post. Should be here later in the week. I've downloaded the free version of the software. I'll have to set my desktop PC out on the bike box in front of the car as I have no garage! I just hope this shows up the problem.
I'm pleased to read that the fault is unlikely to be injectors. At the last service the mechanic changed one of the injectors because he said it was leaking petrol. When I cleaned them last week I noticed that the new one has only one nozzle, the others have six; is that likely to be significant?

The injector difference sounds very suspicious. Did you note the part numbers? Was the fault there before the last service? If not I'd be talking to the garage who changed the injector.


Robert G8RPI.

 

[jackwhoo]

Well done spotting different injector.
Suspicious for sure.
If its easy for you have a look at the injectors again sometimes they have ID numbers on them.

 

[Neil Ives]

The injector difference sounds very suspicious. Did you note the part numbers? Was the fault there before the last service? If not I'd be talking to the garage who changed the injector.
Robert G8RPI.

Didn't look for part numbers.

Before the injector change the car was running well. I had noticed some petrol smells so when the mechanic said an injector was leaking I was not suprised.
The recent problem did not start imediately after the injector change which was last November. The other injectors are the originals; I've had the car from new.

 

[Neil Ives]

worthwhile check is the HT leads and coils ...because symptoms are classic weak spark failing under load.

While waiting for the lead set to use with MultiECUscan:
The symptoms are, engine not wanting to run on start up especially when hot. Then when the engine starts it's only running on three cylinders. This clears after about a minute. Smells of unburnt fuel! The car then runs as well as ever; top speed is good; acceleration is good. When climbing steep hills the engine sometimes shows signs of misfiring, (I guess that might indicate breaking down under load). Do you still think weak spark could be the issue?

 

[jackwhoo]

If you want to look at something before MES you could pull the spark plug , keep note of which plug is from which cylinder , compare the looks of the firing ends for differences (particularly the one with odd injector)

 

[portland_bill]

Injectors should all be the same, so worth querying with the fitting garage. Possibly an aftermarket one, listed for multiple engines, but there's a difference the manufacturer has not caught up with.

Plugs hopefully will give a clue as to which cylinder is misfiring.

Once you have MES, plug it in and see the readings before starting the engine, then as started, watch them and see if they change as expected. Duff temp senders or other sensors can give acceptable, but wrong, readings, so ECU does not realise they are wrong.

 

[Neil Ives]

Something new today. Started the car, with the current reluctance. When I started to manoeuvre there was a strange rubbing, squeezing feel as I turned the steering wheel. I had to have a look underneath the car to see if something was caught. The sounds cleared when I started to drive. Electric power steering problem maybe? Could this be connected to the misfire problem; I'm imagining a faulty ECU causing mayhem?