hi, i have had my felicia fun a couple of weeks and noticed an intermitant missfire, at first i put it down to lack of use, previous owner did only 400 miles between MOT's but its getting worse, i have replaced the plugs, rotor arm and air filter, i am looking for ideas of where to look next, should i be looking at another coil or could it be injection/ fuel problem, poor thing has nearly 150000 on the clock, any help appriciated

Edited 13 March, 201511 yr by VmaxGazza

My 2 cents.

Given the fact an intermittent misfire issue could have multiple causes, you'll end up going bankrupt by throwing parts at car instead of diagnosing the problem first. AEE engine is not my cup of tea but I am sure that Fun experts will tell you exactly what to do. I will only list some of generic probable causes:

 

Mechanical related

• compression issues
• carbon deposits

Air related

• vacuum leaks

Fuel related

• dirt issues (injectors, throttle body)
• pressure issues (fuel pump, pressure regulator, injector o-rings)

Electrical related

• corrosion and moisture (connectors, wires, relays)
• arcing

Edited 13 March, 201511 yr by RicardoM

Does the intermittent misfire coincide with a downpour of rain?

Does the intermittent misfire coincide with a downpour of rain?

hmmm, not sure as its been damp here since i bought it, is there something i should be looking for or would a good soaking in WD 40 be an ooption?

Ricardom, thanks for your reply, yeah i need to trace the fault rather than chuck money at her

hi, ive just sprayed 1/2 a tin of carb cleaner thru the throttle body, its made a difference, tick over has gone upto 1000 revs and seems more responsive

 

i also sprayed everywhere with WD40 as its been dry today and its ran without missing

 

i'll keep you posted

is there something i should be looking for or would a good soaking in WD 40 be an ooption?

The video linked below should give you a generic idea about testing properly for 'arcing'. Watch it carefully. Listen carefully.

 

https://www.youtube.com/watch?v=6f9Qxmhc10s&feature=player_embedded&hd=1

Edited 14 March, 201511 yr by RicardoM

The video linked below should give you a generic idea about testing properly for 'arcing'. Watch it carefully. Listen carefully.

 

https://www.youtube.com/watch?v=6f9Qxmhc10s&feature=player_embedded&hd=1

cheers for that, i'll give it go, i bet you i get zapped lol

i bet you i get zapped lol

No, you won't. The rod of the screwdriver is connected to car's chassis with a wire. Current travels along the path with least resistance, the wire. Your body has a bigger resistance than connecting wire.

 

One last advice, check dizzy cap inside for cracks, corrosion, carbon brush too.

One old trick for poor electrics in damp conditions is to open bonnet at night ,run engine, keeping hands outside and look for arcs & sparks. I see dizzie mentioned and wonder if this an olde system with dizzie and leads + coil. Another old trick from Mini days was to try using a neon screwdriver CLOSE( but not/never on ) the HT leads, looking for signs of leakage. .

Cheers guys for all your helpfull comments. I will see what happens next time it rains. Hopefully on right track now. Thanks

I don't think this is damp related. Even had misfire on dry days.think its picking up gunk from engine breather into the throttle. Given throttle a good clean and trying not to let fuel level get to low. Possible cause being previous owner doing 400 miles between mot for last 3 years

think its picking up gunk from engine breather into the throttle.

Cars have air filters, you know...

trying not to let fuel level get to low. Possible cause being previous owner doing 400 miles between mot for last 3 years

If you think 'gunk' may get from fuel tank into the engine, you're wrong. I don't know how dirty is UK petrol, but usually the fuel tank is not a dumpster. The only thing that may pass from fuel tank to engine is water. Try filling the tank with petrol from another company. Old fuel may also be a factor. Dirty/foul injectors too. Clean them and maybe Miss Fire will go away.

Edited 29 March, 201511 yr by RicardoM

Cars have air filters, you know...

If you think 'gunk' may get from fuel tank into the engine, you're wrong. I don't know how dirty is UK petrol, but usually the fuel tank is not a dumpster. The only thing that may pass from fuel tank to engine is water. Try filling the tank with petrol from another company. Old fuel may also be a factor. Dirty/foul injectors too. Clean them and maybe Miss Fire will go away.

No mate. I think gunk is coming from engine oil.I suspect the engine has never been up to temperature for years. I was told that it was driven every Saturday night.but if you devide 400 miles by 52 weeks its only a few miles , possibly never left the town centre !!