S16 Intermittant Misfire

[jims205s16 1]

hi everyone been searching but cant find an answer yet hoping you can help

have a 306 s16 engine in my 205 was running fine then misfiring lost 3rd cycliner changed all coils and plugs as had a new set and this solved the problem as number 3 coil had gone was fine for maybe 2 days

now i have an intermittant misfire runs fine from start up (cold) and drives fine then when about quarter warm it will miss fire revs all over the place rough tickover if you drive on about 15-20 seconds it clears and will run fine. problem only comes back when ticking over when hot (always in traffic on way to work) where it remains untill have a chance to drive for 15-20 seconds again continuous and clears itself.

it is using alot of fuel at the moment as well

any suggestions welcome please

[welshpug 1,666]

from what you say it sounds like a dead ECU coolant temperature sensor if its using a lot of fuel and is temperature related (shouldn't be ignition as you say you have replaced the coils)

 

check the resistance across the sender when the engine is cold, pretty sure the specified tolerances were posted up.

[welshpug 1,666]

eit; try this

 

[kyepan 291]

check out the stick for the caps program, it will detail very simply how to diagnose what the sensor should be outputting.. all you need is a multimeter.

[jims205s16 1]

thanks ill have a look this weekend ill let you know how i get on cheers for the advice

[jims205s16 1]

hi tried temp sensor but no change been driving around and still the intermitent misfire

today on the way home it went and never returned to normal nursed it home and cylinder 4 not sparking at all i had changed all 4 coils for new ones and still had the 3 that were previously working changed it over for one of the old ones and run like a dream again

do you think i got sold a dud one or is there something else that could be damaging the coil baring in mind it only covered 300 miles from new in to knackered

[welshpug 1,666]

is it just the one coil that stopped working? if so I'd be either sending it back to be tested to checking the wiring, there's a big round multiplug on the end of the cam cover that would be a good starting point.

 

 

I doubt its the ignition amps as there are 2, one for each pair of coilpacks, but you could try swapping the plugs round on them to see if the problem moves.

[jims205s16 1]

its was just the 4th, when i changed them the first time it was the 3rd coil that failed i did swap the ignition amps round when i was trying to get rid of the misfire at the weekend which is maybe why the problem moved from 3 to 4

if one of the amps is faulty would they damage the coil its just putting an old coil back on cleared it again (for how long is anyones guess) if the amp was breaking down it would be the same all the time would it not