Technical Funny misfire - any ideas?

[wolvescinq]

Hi guys!

Got a misfire on my Cinq Sporting currently which only ever seems to occur under sudden, hard acceleration. This is accompanied by a strange 'spitting' noise from under the bonnet, as the car lurches forward before the revs pick up properly again. Had the head gasket done not long ago, following a massive coolant system explosion, and this misfire's been a problem ever since. I suspect it could be electrical (the spitting sounds like something short-circuiting) and would be grateful for any advice here. Plus, the heater doesn't seem to be getting very hot - could we also be talking thermostat here?

 

[Pep0]

Open each bleed valve in turn, for the heater efficiency you need to have coolant coming from the bulkhead bleed point.

If the rad hoses are to hot to hold the thermostst is ok.

Stay up late until dark open the bonnet and start engine, if there is blue fire leaking then you will need to replace the plug leads or HT coils...

Noel

 

[fingers99]

As said. The top hose is the critical one (for testing, that is). Thermostats are only about 15 quid and a duff one is a likely cause of head gasket failure. Get one with a name stamped on it, rather than just the temperature it opens: I've seen cases of no-name ones failing within 2,000 miles!

 

[rallycinq]

I would suggest that the spitting is a timing issue, ignition firing through the induction.

Check the timing is spot on, the crank sensor is sitting square and the vacuum pipes/map sensor are all spot on.

Cheers

D

 

[blu73]

crank sensor can get very dirty and give weird readings so clean it up while your there.

 

[little J]

i have the same problem!!

just started doing it today.. and ive just replaced one of the coil packs and the HT leads..

i have a 1999 0.9 seicento..

just when your at part throttle sometimes it stumbles
and sometimes when you put your foot down, it bogs and then after a moment it starts firing again..

: (