Missfire!!

[ian00uk]

had this problem for few months now. when accelerate past bout 2500 revs the car missfires and pops out of exhaust real bad.things ive done is

new coil packs from vw
new spark plugs for vw dealer
new cat as old 1 had hole in it so thought this could have contributed to it
cleaned throttle body and reset

the car now struggles when idling and pulling off and going at low speeds.
also when i drive it a bit and then stop the fan comes on for about 5 seconds then goes off.

plugged into vagcom and it comes up with

cylinder 1,2,3,4 missfire and random missfire

any ideas?

[BobbyT]

what do vw think buddy? 

[ian00uk]

dont know havent been to them, they will charge loads to look at it so thought id post on here see if any1 had ne ideas.taking it to few garages tomoz see wat they suggest

[topher]

Usually my first thought with things like this is MAF, but the vagcom result doesn't really back that up. How many miles has your car done and has the timing belt been changed? May have jumped a tooth..

[ian00uk]

its done 73000 miles and had an engine rebuild on 67000 miles where it had the timing belt changed and other bits.how often should timing belt been changed?is there a way to check it? i replaced the maf bout 4 months ago

[topher]

It should have been changed when they did the rebuild.. if its messing up after only 6000 miles i would've thought the first port of call would be the people that rebuilt your engine?

[ian00uk]

yeh but its been fine since rebuild until last couple of months.trying to narrow it down what it could be.

[topher]

any local backstreet garage should be able to check your timing, which might atleast eliminate my jumped tooth theory!

[ian00uk]

ok mate will speak to em tomoz.thanks for ure help