1990 e30 318 engine problem

[Butterfly 0]

hi all i have a small problem with my girl friends 318 e 30 when driving and holding my foot steady on the throttle the motor serges wich is real anoying and i think its causing bad fuel consumption too could this be an air flow meter problem? i recentley unplugged the afm to drill the air box could this course the problem??? or should i be looking some where elce any help would be great and should score me some browne points haha

[pureboiracer 0]

possible. check connections and clean if they look dirty. also check sparkplugs ht leads and timing. surging is usualy caused by incorect or incomplete combustion im pretty sure. so check all things like ignition. air intake and maby clean fuel system. sound like just needs a good tune.

[drobson 0]

hi all i have a small problem with my girl friends 318 e 30 when driving and holding my foot steady on the throttle the motor serges wich is real anoying and i think its causing bad fuel consumption too could this be an air flow meter problem? i recentley unplugged the afm to drill the air box could this course the problem??? or should i be looking some where elce any help would be great and should score me some browne points haha

Hey there, with any luck you've already sorted this problem-I haven't been online for quite some time so have only just seen your question.

Sydwayz advice is good. Further to this advice, check in particular all "vacuum" hoses for perishing, cracking, poor fit etc. There are a number of rubber vacuum hoses around the intake manifold area such as to the fuel pressure regulator and the PCV hose from the rocker cover to the air intake ducting. Check all the air intake ducting as well.

Any air "leaking" into the system after the air flow meter is not "measured" and the engine therefore runs lean causing surging.