slight misfire

[pulsarmad20]

hi

my car has a slight misfire on idle and soon as i hit about 5 thousand (in gear driving along) revs it wont go any higher its like its miss firing but then slowly builds the rest of the revs up but doesn't sound to good.

in neutral it will rev freely through the rev range..

thanks

sam

 

[whytie]

Have you done a fault code check?

 

[pulsarmad20]

yea it comes up with nothin :$

 

[PobodY]

What are your plug like; are they gapped right?
Timing?

 

[pulsarmad20]

spark plugs brand new and timing is set a 20 deg

 

[PobodY]

Just because the plugs are new doesn't mean they are gapped right; did you check them before they went in?

 

[pulsarmad20]

they are bosch platin ones and they are set at 0.6 gap

 

[PobodY]

Isn't that a bit small? I run 0.9mm on copper cores, but I think the standard is 0.7mm. - I know I was loosing power when my plugs were gapped at 0.5mm, but I didn't notice a misfire. However, the power curve goes up then drops, then starts building again... which sounds a bit like your description.

You haven't "uprated" your leads have you?

 

[pulsarmad20]

has standard ht leads

 

[GTiR_Lee]

I have a very similar ,if not the same problem at the moment .
Don't know about going past 5k tho as im being gentle with it .
Check your dissy cap , i checked my and two of the four points are worn so much that they are in dented into the plastic . So can't be getting a strong enough spark .