6000rpm missfire????

[ELLIS GSI]

my car has just started missfiring at high revs about 6000 rpm or just before. could the problem be somthing to do with the ignition timing? has anyone had this problem before??

EDIT. its a 1.6 8v

[mulletor]

check your dizy cap and rotor thoroughly. fuel pump ok.

[AlexW]

Carb or injection?

[ELLIS GSI]

dizycap and rotor are ok fairly new. fuel pump is not making any funny noises or owt.

it is mpi with a kent nvo51 cam.

thanks for the help so far.

[ELLIS GSI]

bump. its still the same. i got the ignition timing set and still no better? the camshaft hasn't been in the car long, could it be something to do with that? im scratching my head now.

[ELLIS GSI]

sorry to bother you lot again but is is sill the same. i changed the full new distributor, tryed the coil and ignitor off my mates car, the ht leads are fairly new aswell as the spark plugs. and iv just changed the fuel filter and still not better. as i hit 6000rpm the car really splutters like its not firing. wen it does it and then i go into the next gear it feels like is got the residue fuel in the cylinders then splutters in the next gear for a brief second, then pulls well untill 6000rpm again. what else can it be??? need it sorting for pvs

[MC]

When did the missfire start? Did it coincide with anything else, changing cam etc?

MC

[ELLIS GSI]

could of started after i put a new clutch and lightened flywheel in. could it be a earthing problem?

thanks mc

[MC]

Have you always revved this high? or do you go higher now as a result of your mods? It's not the rev limiter is it? Might sound silly but want to build a picture.

Normally high speed missfires are associated with ignition. Is it silky smooth throughout the rest of the rev range?

Who installed your camshaft and was it fine after that?

MC

[rysmee]

i was going to say it sounds like the rev limiter. I'm guessing though that the ecu would cut fuel and not spark as its dizzy, so wouldn't explain why it coughs and splutters for a brief second after changing gear.
The power band for that cam is only 5500rpm so surely your well out of power by then anyway??!!!

[ELLIS GSI]

the rev limiter is about 7k. i havent been revving the nuts off through the winter so only noticed it recently.

its fine and silky smooth through the rest off the revs.

i fitted the cam.

and it pulls well all the way untill it plays up.

[ELLIS GSI]

also when it is sat at idle for long periods of time like in trafic the revs drop for a brief second like it wants to stall but only every minute or so?

thanks MC and rysmee.

[CP]

Go to an enigne diagnositcs place. Check the cam shaft timing and the ignition

[saloonwoody]

was it originally a mpi car ??

[ELLIS GSI]

Go to an enigne diagnositcs place. Check the cam shaft timing and the ignition

i will cheak the cam timing tomoro then. if it was a tooth out could it cause this?.

will diagnosis comp bring any codes up if the warning light is not on?

it is an original GSI mpi

[rysmee]

if it were a tooth out you'd know! and it wouldn't explain why its only at that particular rev range.