Technical Mysterious misfire....

[Cureforsanity]

Hello good folk of FF!

Help! Someone....ANYONE....please?

My former car (now owned by another good friend of mine) 2001 Seicento Abarth. 36K on the clock's started to run like a sack of turds, sounds like it's running on 3

NOW, it used to do it from time to time but now it's all the time and the engine light's on.

It was throwing a faulty coilpack code up so I got my very good friend who's Sei runs perfectly to donate one to me to see if it corrected the problem

It didn't. In fact my code reader then threw up a problem with BOTHJ coils so we swapped both over. No difference. So we swapped the HT leads. Yay, success! Ran perfectly for about 10 seconds then BOO!!! Back to running on 3

It's had new plugs not long ago when I changed the oil & filters

I've followed the wiring from both coils and it's not broken or chafed at all.

If you remove the HT leads when running it sparks fine on 3 but on the fourth one (second one down on the top coil pack as you're looking at the end of the engine) there's a bloody huge long spark arcing all over the coil pack which still does it when the coil pack is replaced

I'm out of ideas except one....

Could it be the ECU? It's one of the small finned items about 4" x 2"

ANY advice would be welcomed even if it's 'Burn it' or 'scrap it'

 

[Ady117]

Clean your HT Leads make sure they have no grime on them at all...check the ht plug caps are good and still connected see if that works.... if not change plugs round... see if that works

 

[Cureforsanity]

Sorry, forgot to say I swapped his HT leads over and it made no difference

 

[rallycinq]

The ECU switches the earth from the coils.

Its looking like an ecu issue, but they can be repaired

D

 

[henseyseries3]

If it’s the micro ecu (very small one) there common for killing the coil driver causing a misfire

I’ve also had a crank sensor cause a random missfiring issue

 

[jackwhoo]

Hello good folk of FF!

Help! Someone....ANYONE....please?

My former car (now owned by another good friend of mine) 2001 Seicento Abarth. 36K on the clock's started to run like a sack of turds, sounds like it's running on 3

NOW, it used to do it from time to time but now it's all the time and the engine light's on.

It was throwing a faulty coilpack code up so I got my very good friend who's Sei runs perfectly to donate one to me to see if it corrected the problem

It didn't. In fact my code reader then threw up a problem with BOTHJ coils so we swapped both over. No difference. So we swapped the HT leads. Yay, success! Ran perfectly for about 10 seconds then BOO!!! Back to running on 3

It's had new plugs not long ago when I changed the oil & filters

I've followed the wiring from both coils and it's not broken or chafed at all.

If you remove the HT leads when running it sparks fine on 3 but on the fourth one (second one down on the top coil pack as you're looking at the end of the engine) there's a bloody huge long spark arcing all over the coil pack which still does it when the coil pack is replaced

I'm out of ideas except one....

Could it be the ECU? It's one of the small finned items about 4" x 2"

ANY advice would be welcomed even if it's 'Burn it' or 'scrap it'

Possibly faulty spark plug
, Change the plug on the cylinder causing the problem.