Megane misfire - not coils?

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Mon 24 May 2004 09:35
Megane misfire - not coils? - davemar
My 1998 Megane 1.6 8v has just started to occasionally splutter at low revs. Sometimes the idle drops, but more usually it happens when pulling from low revs it has a little miss. I doubt it is the HT coils causing the problem, as they have both been replaced in recent months and the symptoms are not the same as failing HT coils (as I know from experience).

The symptoms have only start since I had a cambelt change done a few days ago. So could that affect things? I could go back to the garage, but I'd rather has some idea to what the problem is first. If I took it back to the garage you can guarentee the problem wouldn't occur too!
Reply | Report as offensive | Link
Mon 24 May 2004 23:54
Megane misfire - not coils? - David G.I.Davies
The first thing I'd check with this would be the earth connections at the cylinder head on the offside.There is one large earth braid which you can easily see and two smaller wires which earth the engine management system,the latter are hidden from view from above.They would have been disturbed at the recent cambelt change.
Reply | Report as offensive | Link
Wed 26 May 2004 07:49
Megane misfire - not coils? - Andrew Moorey (Tune-Up)
Spookily had a similar prob a few days ago. The vacuum port on the inlet manifold to the map sensor was blocked causing the symptoms you describe.
Andrew


--
Simplicate and add lightness!!
Reply | Report as offensive | Link
Wed 26 May 2004 10:20
Megane misfire - not coils? - davemar
I've just checked both the good suggestions. The ground strap was still securely fastened, so that didn't seem to be the cause. I also checked the little hose to the MAP sensor and that didn't have any splits or blockages. I ought to check the other breather hoses too for splits just in case.

I'm going to put some new HT leads and sparks plugs on to see if that fixes things. The plugs are probably due for a change anyway.
Reply | Report as offensive | Link
Fri 28 May 2004 12:26
Megane misfire - not coils? - davemar
I replaced the spark plugs and that has seemed to have fixed it. The old ones looked well worn, and it was probably just coincidence that they started to miss just after the cambelt change.
Reply | Report as offensive | Link