Help!! Major flat spot/missfire

[Thundersmurf]

I've got a major issue with my car and I really need it this week :(

It is idling slightly lumpy but the main problem is when I start to set of it just stalls, no matter what I do.

If I rev the engine out of gear it gets to a certain point and nearly cuts out but then revs again, the revs go up and down like a tart's knickers when I keep the throttle at a certain point.

Any ideas what is causing it? Any help would be really appreciated.

(it's a 1989 1.2 merit by the way)

[MK1-GTE]

plugs/leads/distributor cap would be a good place to start looking/checking mate ...has it been driven in heavy rain recently ?as the dissy caps do suffer from moisture ..
also fuel filter is worth a check over/replace...
hth al

[Thundersmurf]

sorry forgot to say it has had recently:

Plugs
leads
rotor arm
dizzy cap


I'll check the fuel filter

Could it be the coil pack??? just a thought...

Another thing that I forgot to mention is that it runs ok on choke, which is what makes me think it isn't a points/fuel problem etc, surely that would be even worse on choke???

[*Dave*]

fueling problem in my opinion, fuel pump,filter.

[Thundersmurf]

but wouldn't that problem(fuel pump/filter) still be there on choke?

[Welsh Dan]

No, the choke restricts the airflow, not the fuelling, making less air flow into the engine faster, but richer.

[AlexW]

Are you taking the choke off before setting off? before its warm?
Is the vacum advance pipe on?

[rysmee]

have you got an air leak somewhere? ie after the intake so either gaskets on carb or around inlet manifold? that would explain why it is improved on choke. get some wd40/ dwf and when the fault is occuring spray it around the manifold area and other potential air leak points, if there is an air leak somewhere it will momentarilly improve.
eliminate the fuel pump/ filter by putting a guage to see what the pressure is doing when the fault occurs. if the pressure remains constant (not below 0.19 bar) then there's no problem.

[Thundersmurf]

ok guys thanks for the info - I'll give all that a go.... cheers!! :)

[leenovagsi]

ive just had same symptons on my 1.6 gsi found out yesterday wen the coil decidid to die in the rain got rather wet lol, if u can check resistance of your coil if its ok check all other leads to dizzy i know u say most of the bits are new but neva rule em out

[Thundersmurf]

I've sprayed around the carb and it does make a difference so it's looking like it could be an air leak. Gonna try and get a new gasket tomorrow.....