missfire

[audis2dave]

can any won help ive got a harsh miss fire not all the time comes and goes only when i floor it if u drive it normal will never happen any information will be great

[Big Lee M]

Sounds like the coilpacks are starting to give up. Mine did it when it was warm and under full boost. I have replaced mine and everything is fine now.

[Knight Rider S4]

What model is it ..3B?

[audis2dave]

rapid replys i like this forum yer its a 3b happens when its warm cheers

[Big Lee M]

rapid replys i like this forum yer its a 3b happens when its warm cheers

Sorry never thought to think of that as mine is a ABY the info i fed you is useless

Have you changed the spark plugs? My brother had the same problem on his 200sx it turned out to be the spark plugs. Cheap (ish) and easy fix.

[newsh]

If its a real "slam your head into the dash" type violent missfire thats known as overboost cutout or MAF cutout. Could be a boost leak or the MAF or even just the MAF connector needs a wiggle and a clean. Roll the window down and listen for a hissing/squeeling noise on boost, if so its a boost leak and your best bet is to pressure test the inlet tract.

Check and clean the MAF connector first though and see how it drives then.

[audis2dave]

yer im going to giv a good service this week i think its down to plugs or something previous owner hadn"t used it in a while what mpg should i be getting when giving it some put £30 super in and got 110 miles thanks for the help

[audis2dave]

the maf connector is very lose missing the clip thats got to be it i think i pushed it on yesterday its working its self lose spot on will sort this in the morning thanks guys

[audis2dave]

just seen your location dorking surrey thats where i bought this s2

[UrS4boy]

the maf connector is very lose missing the clip thats got to be it i think i pushed it on yesterday its working its self lose spot on will sort this in the morning thanks guys

Two words: Zip Tie

(or Zap Strap)

(the nylon wire wrap/ties)

Use a long one to hold your connector on.

(?)

[URSIMPO]

My car has started to missfire. I replaced the front intercooler clamps - as they were jubilee. At first the car went like a rocket, then after driving on the motorway (that night) there was massive hestiation from about 3.5k. It made a strange 'farty sound'. I thought it must have been boost leak as it was too coincidental.
However from cold there is no hestiation, only after its warm.
Plus as described newsh above, I had MAF or boost leak cut out yesterday (thought the engine was gonna break the mounts!). I have tightned the clamps to the max.
Is there any way to test the coilpacks - I have the 1.8t conversion.

[URSIMPO]

Problem has been diagnosed: It's the coil packs. Gonna replace all 5 tomorrow.

[audis2dave]

car is running lovely now ive plugged the maf plug in was hanging off cheers for the help guys