misfiring engine

[rmangual]

i have a 1991 tsi with these mods:
t4/t3 50 trim
2g mas unhacked
dejoon ic and piping
rc 550 cc inj
magnecor wires
ngk plugs 1step colder
hks sqbov
3 in exh
cometic head gasket with arp studs
safc
walbro 255lph

the problem i have is that the car idles real rough and it misses and low throtle crusing , it starts right up but like i said it misses bad it wont even red line in neutral, so i did a comp test and all the cylinder have 160+ , so when i check the spark plugs there black , also i send my ecm to get rebuild thinking that it was the problem, put it back in the car but still doing the same, could it be and ignition related problem also it smokes pretty bad, so i check the fluids and all ok so if its running that rich that could be the reason for the smoke? any help will be appreciated.

 

[Enigma_Man]

heh, I thought you meant something entirely differently from your Subject line

You're running rich if you have no form of electronic fuel control. The ECU still thinks it has 550s, and even though you have a 2G MAF, that's not going to be a very good correction.

-Jesse

 

[GSGoinFast]

Now i dont have a turbo or near the amount of mods you have but my 2g did the same thing about a month ago or so. One day i felt a little jerk in 2nd and 3rd gear. the next day it was a big jerk and started misfiring 3 or 4 times each gear except for 1st. It idled rough but never misfired while idleing. it was horrible at low rpm's but after it got past around 3,000 it smoothed out. One of my wires was shorting out. the plug for that wire was black too. i just replaced my wires and plugs and it ran like new. if this sounds like what your car is doing then try replacing the wires.