hi ive got a 1995 wagon turbo mods are :

td05
front mount
z4 ecu
mushroom hks
standard fuel pump
standard injectors

the problem im having is car starts and runs sweet up to 5000 rpm and boosts with no issues, anything after 5000 starts to what feels like a missfire as i havent done the plugs for a while i got a new set and gaped at 0.7 and replaced the coil packs as they fell into pieces looked like the originals to be honest but problem is still there ive cleaned the maf there are no cel lights on or codes could it be the standard pump or inj ? any ideas thanks mark......

 

Check your fuel filter bud,

 

mapping might be an issue.

 

front mount with no re-map........crap running and bang.

 

the z4 has been chipped usual fuel cut raised 18 psi boost raised to 16 psi timing advanced, 112mph removed apparently i no its not a map ! but ran ok before ?

 

Did you replace the coils with known working ones, new ones, or 2nd hand, they can look fine but still cause hassle,
Why don't you convert new age ones, sound like they breaking down when needed

 

that`s what worries me i brought some second hand ones off here the other week cheap! 3 were ok the other one was in pieces same as mine how hard is the conversion ?