[ml55 500bhp]

Some of you may remember that i said that my 55 wasnt running right, it seems to be a bit worse now! I have changed all the spark plugs today, no change, took it to have a diagnostic check on the computer, came up with missfire on all cylinders except cyl 1? we took it for a drive whilst it was still attached, he said that it seems to be running lean? He said that the MAF was fine, so havent cleaned or changed that. so i am going to change the fuel filter next, i also took it to an exhaust specialist, he thought that the cats were fine, (as i was thinking that it may be back pressure from cats)

my car runs fine under normal conditions, but if you accelerate hard or drive at high speed this is when the power loss occurs?

what you guys think?
any help appreciated, (least cost options!)

 

[ml55 500bhp]

61k
I also put some injector cleaner in yesterday to see if that helped a bit, done a few miles with it in now and it hasnt helped......

should i change all the wires then?

 

[ml55 500bhp]

played about with it today,
i dont understand why under normal conditions it runs fine? only under higher acceleration does it seem hampered? if i select first and try and accelerate, it is really sluggish and missfires but if i accelerate in 3rd at 2000rpm it is fine????
would the wires not cause a constant problem? the lack of power under higher strain leads me more towards fueling? i have been told that the maf is working fine, he was checking it whilst we were running, but i will clean it anyway, i checked the cats tonight to see if they were glowing and getting too hot, they weren't i also banged the silencer boxes and no sign of it breaking up? so dont think it is exhaust, but the symptoms to me, seem like problem getting rid of the air quick enough? heres another one for you, i managed to get upto a reasonable speed (not saying how fast, but fast enough) when the car really started to missfire and slow down, i pulled over re-started and it was fine? huh????????

HELP!

 

[ml55 500bhp]

thanks rob, it does sound very familiar, diy wire change for me then! fingers crossed!

 

[ml55 500bhp]

rob you owe me $50! it was maf! this thing must of been clogged for 6 months! never been like it is now! like a rocket! yipee! bloody 10 min job fixed it!

 

[ml55 500bhp]

all i would say guys if anything is wrong check the bloody maf first! i only cleaned mine with a brush! i nearlly got rid of my 55 as i thought is was rubbish! NO CHANCE NOW! plans back on, i will post you guys when i have my body kit on, i havent seen a picture of the kit anywhere other than the ukraine where i am getting it from,