rb20det high idle & dies after rev - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

3v1Ls14 · 10-06-2012, 12:13 AM

rb20det s14
afpr
front mount i/c
25det turbo
everything else practically stock

it will start fine has a miss at idle, idles quite high and i cannot adjust it

i can lower idle by unplugging aac connector, but not by adjusting screw. tps set correctly

once its running if i blip the throttle it will rev out and then die when the revs drop back down. drives ok except for this and will randomly start miss firing. has wasted spark setup brand new leads new coil new plugs.

plugs foul up quickly

afm voltage within spec

injectors all operating to spec

vacuum at idle is 19-20inHg. with aac unplugged it fluctuated from between 20 inHg and as low as 10inHg just fluctuates between these values but not in rapid succession as hunting, a slower fluctuation in the idle speed.

any ideas would be appreciated as i have looked for hours and hours on this thing now and im getting kinda stuck where to go next.

cheers

RB240Coupe · 10-29-2012, 07:15 PM

is it miss firing while under boost?

3v1Ls14 · 10-30-2012, 02:05 AM

Quote:

Originally Posted by RB240Coupe

is it miss firing while under boost?

yes and no.

it will misfire off boost and drive shit but then hit boost runs on 6 pulls well. other times it will occasionally miss on boost but not badly.

RB240Coupe · 10-31-2012, 03:00 AM

what are your plugs gapped at?
are you still using the Rb20's maf or did you upgrade ?

greenwood · 10-31-2012, 05:12 PM

it sounds like a vacuum leak personally. are you sure there are none? Have you tried doing the old battery unplug, replug in after pressing the brake a while?

10-06-2012, 12:13 AM	#1
3v1Ls14 Leaky Injector Join Date: Jan 2012 Location: New Zealand Age: 28 Posts: 85 Trader Rating: (0) Feedback Score: 0 reviews	rb20det high idle & dies after rev rb20det s14 afpr front mount i/c 25det turbo everything else practically stock it will start fine has a miss at idle, idles quite high and i cannot adjust it i can lower idle by unplugging aac connector, but not by adjusting screw. tps set correctly once its running if i blip the throttle it will rev out and then die when the revs drop back down. drives ok except for this and will randomly start miss firing. has wasted spark setup brand new leads new coil new plugs. plugs foul up quickly afm voltage within spec injectors all operating to spec vacuum at idle is 19-20inHg. with aac unplugged it fluctuated from between 20 inHg and as low as 10inHg just fluctuates between these values but not in rapid succession as hunting, a slower fluctuation in the idle speed. any ideas would be appreciated as i have looked for hours and hours on this thing now and im getting kinda stuck where to go next. cheers

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10-29-2012, 07:15 PM	#2
RB240Coupe Leaky Injector Join Date: Jan 2012 Location: virginia Age: 32 Posts: 57 Trader Rating: (7) Feedback Score: 7 reviews	is it miss firing while under boost?

10-31-2012, 03:00 AM	#4
RB240Coupe Leaky Injector Join Date: Jan 2012 Location: virginia Age: 32 Posts: 57 Trader Rating: (7) Feedback Score: 7 reviews	what are your plugs gapped at? are you still using the Rb20's maf or did you upgrade ?

10-31-2012, 05:12 PM	#5
greenwood Zilvia Addict Join Date: May 2011 Location: nc Posts: 618 Trader Rating: (5) Feedback Score: 5 reviews	it sounds like a vacuum leak personally. are you sure there are none? Have you tried doing the old battery unplug, replug in after pressing the brake a while?