Misfire/flatspot

[beni-iow]

ive recently changed all my filters plugs leads dizzy cap n rotor arm on my gti 8v and im still geting a misfire/flatspot when i power off the line hard or change gear fast,and im now confused what it could be causing this.ive read that some people have had problems with there ecu relay and fuel realy?could this be causing my problem?also ive noticed that the twin black breather pipe has a split and feels like its perashing but when i went to see how it came off i could not get the black cover thing they go into to come off the top of the engine i removed the 2 screws but i would not lift off is there a special way any help and advice is much apreteated.

thanks ben.

[Stu G]

take it your engine is a 2e.the pipe your on about is there a little black box on the rocker cover one pipe goes into the air feed in the manifold and one runs down the block. that wont be causing your misfire. try the rotar arm as well. that might cause it. apart from that im stimped. i had a misfire replaced plugs and leads and was cured.

im sure more people will reply later in the day

[Mk3_Mac]

I've just had mine serviced and the mechanic diagnosed that it was very flat...disconnect the air mass sensor and it was like driving a new car.
Replaced dizzy cap, rotar arm, sparks, and leads and now runs sweet...
Try disconnecting ur AMS clip and see how it goes??

[beni-iow]

ive put a new rotor arm and cap on.so if i disconect the air mass sensor it could cure it then?is that what you mean?

ive also noticed that if i just tap the thottle the car seems to misfire and pops ma bit.

[Mk3_Mac]

I only disconnected it to see what it should have felt like. Have had a new one installed now and it runs much much better.

[boneybradley]

any leaking breather pipe will cause missfires...but i would recommend cleaning the throttle body as well as its cheap and simple to do...and what year is the car as i'm guessing mk3-mac's is a 94 onward with siemens injection..like this

[G60GTI16V]

i have spent all day working on the red beast, changed the rear back box with new one from euro BARGAIN!!!!!!! 43 inc clamp WITH STAINLESS LOOKING ENDS!!!! i will upload well worth the money.

other than that i took the starter motor off and apart cleaned it and damb does it spin up nice now!!!!

also cleaned brether pipe and throttle body WOULD DEF RECOMMEND was full of crap!!!

i have changed ecu relay & temp sensor still have this mis fire like you guys so im guessing it could be the mass sensor this the big one on the end of the intake pipe filter end?

i have not changed plugs and leads as these were change 5 months ago and looked healthy as i took one out to inspect.

dan

[boneybradley]

vag-com time..... the mass sensor should show a fault code up!

[saul79]

it would be lack off power when you boot and hestitate/missfire if the maf sensor is faulty and it will show up a fault code too.dont drive it to long with a missfire or you will be replacing the cat aswell 

[G60GTI16V]

which one is the mass sensor? the one on the top at the begining of intake square shaped 3 pins? i did pull this off and reved it a few time didnt make any diff, i think its either coil giving poor power or the plugs because this morning when i started it a puff of smoke came out which is rich of fuel so its got to be the poor spark. no?
dan

ps whos got a vag com i can borrow?