Technical FIAT MIARA 1.6 16v MISSING PROBLEM

[ken1951]

Could anyone help with this problem...

The car misses and the loss of power gives the impression that your getting held back

I have changed the limbaith senors (Both),put on a new cat and exhaust, but still have a n a miss and loss of power. Done a compression test on No.3 cylinder that looked like the problem, but was ok. Changed the plug (some discoluring to the plug). Checked the lead, but when I take No3 off the top of the coil the engine does not die like on the other ports.

Any suggestions would be greatly accepted.


Ken

 

[hormanncinq]

HI

Sounds very much like your coil pack on that cylinder has packed up. If you take the HT lead off the suspect cylinder and it does not change the idle speed/sound then that says that its not doing anything when its on there. Have you tried another HT lead on that cylinder? You could also put a spark plug into the lead and earth it on the engine and see how good the spark is and then do the same with a different cylinder and compare the spark strength. If you do this make sure that the engine is off when touching the spark plug or you will get a nasty shock from it!! I have had the same symptoms on quite a few modern cars and it is nearly always the coil pack dying.

Hope this helps. rich

 

[ken1951]

Thanks Rich,

Im gona have another go at it on Sunday. Ill let you know

Ken

 

[ken1951]

Hi Rich,

I changed the coil and that seemed to stop the problem for a few days, then a spark plug went. For some reason a spark plug will go after a few days and bing back the problem at a smaller scale. Its as if its losing its spark on spark plug 3.

 

[polecat]

If you are burning plugs in one cylinder I would normally suspect a damaged thread, is this the same cylinder that passed a compression test?

Otherwise look at the electronics, you could have a timing fault causing pre-ignition. Have you checked the leads?

More seriously heavy deposits on a cylinder could cause a pot to run hot or a valve may not be seating correctly or sticking slightly.

 

[ken1951]

I have changed the leads, plugs, coil, compression checked. Car will run ok for a day then a miss will come in. I am starting to think it may be the ECU. Whats do you think?

 

[polecat]

It's possible. It could work out cheaper now to take it in for a diagnostic next time you start getting a miss.

 

[ken1951]

Ive been to the machone numerous times, which comes up with multiple faults. Which are all then reset, car will run fine then they've all been reset but then goes again after about a day

Ken

 

[polecat]

If the garage is seeing faults then they should be investigating the cause and not just simply resetting them. ?

 

[Kevin Williams]

Hello,
New to the forum. But have you tried the fuel injector on that cylinder. It may be causing a weak mixture or bad spray pattern. You may be able swap injectors or just use an injector cleaner.
It can come and go, when you get everything perfect ie, new plugs etc it works for a short time then the weak mixture screws up the perfect setup and starts to miss again.....

I've had this problem on other cars.

My current car is marea 1.6 16v...

 

[lyricalmagician]

How the hell can it be a coil pack. The engine management light would come on and make it obvious. The problem sounds as if your fuel is getting blocked somewhere, and then suddenly it all comes through. When was that last changed?

 

[lyricalmagician]

It's possible. It could work out cheaper now to take it in for a diagnostic next time you start getting a miss.

Or alternatively, dont be stupid and pay for one, when you can have it done free by the AA or RAC.

 

[T14086]

Ken,kevin williams has made a valid point which is worth investigating.
Do you know what the recorded errors where by the way?

Coil going down would not always bring the light on & the RAC/AA will just clear the codes(giving dealer nothing to go on) or tow the car to nearest garage.