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Model specific boards => Golf mk4 => Topic started by: Phil18t on 25 October 2011, 19:50

Title: N249 Bypass
Post by: Phil18t on 25 October 2011, 19:50

Had a flat spot/surge at around 2200rpm on light throttle more noticable in 2nd, after looking on here about the N249 bypass solving the problem i carried this out, at first it seemed loads better but i noticed it still has a slight surge at the same sort of rpm now and again. i have a carbonio on so i can hear it dump the pressure even with my foot still lightly on the throttle?? dont know how because the 007 valve is purely connected to the manifold/fpr now? could it be N75 or throttle body needs cleaning?

Title: Re: N249 Bypass
Post by: Wayne on 25 October 2011, 20:21

Dom did send me this excellent guide on the bypass mod, http://uk-mkvs.net/forums/t/265883.aspx

Title: Re: N249 Bypass
Post by: Phil18t on 26 October 2011, 09:53

already done the bypass, not this way tho.. n still got flat spot/surge.?

Title: Re: N249 Bypass
Post by: dellenty69 on 26 October 2011, 12:07

the bypass you have probably done is the actual N249 BYPASS.

That guide Wayne posted is more of a N249 removal.

remove the hose coming from the actuator to the N75 (remove it at N75 end) and clamp the hose off on the end. take it for a drive. that's one way to test the n75, but i couldn't imagine it due to the requested boost at 2200rpm will be nothing.

have you checked your MAF? unplug your MAF and go for a spin, if it runs better and smoother then that's your problem.

both of those things will cause a fault code to be logged, so you will need them both to be cleared after attempting them.

Title: Re: N249 Bypass
Post by: Phil18t on 30 October 2011, 21:23

anybody know what could still be causing this?

Title: Re: N249 Bypass
Post by: dom on 30 October 2011, 21:59

Only just seen this thread, is the flat spot when your on full throttle/part throttle/both?

Title: Re: N249 Bypass
Post by: Phil18t on 31 October 2011, 21:04

just light throttle mate, like in second and just slowly accelerating off a speed bump..u feel a flat spot about 2000rpm and you can hear a little dump through my carbonio..

Title: Re: N249 Bypass
Post by: dom on 31 October 2011, 21:09

Quote from: Phil18t on 31 October 2011, 21:04

just light throttle mate, like in second and just slowly accelerating off a speed bump..u feel a flat spot about 2000rpm and you can hear a little dump through my carbonio..

Mine has a really bad flat spot just after 2000rpm as well, but only on part throttle, never on full throttle :undecided:

I can't help but if you find the solution then let me know!