Rev issues

[Mr-Hiney]

ok ok, i know i'm on the wrong forums
but maybe u guys know something the nissan boys don't lol

this is about an 1996 s14 k's PFL

when i got the car, the boost/vacuum lines were all jiggered. well, not in the place they should be. so in the last 2 months me and "the lads" have been messing round with the configuration of them. one day i heard someone with the same BOV as me make the big *WHOOSH* noise..... mine never made that, just had the waste gate flutter. so i investigated, found the line to the BOV was plugged into the wrong place. i then plugged it into the line my boost gauge was plugged into. this is when the issues started.

Then we found this service manual that had a diagram of how the lines are supposed to be, so out we went, hooked them up according to their specifications and that just made things even worse.

now when you accelerate (even like a Nana) its revs fine, boosts fine, changes gear fine, but if you let the revs drop right down to idle they just keep dropping to around 100RPM and some times (getting more frequent) it stalls completely. if it doesn't stall, it drops then bounces back and idles like a good little child.

i have checked all lines and made sure there are no air leaks, checked/cleaned the thing nisbits told me might be the problem and nothing. it sounds like my Blitz BOV stays open too long, but that could just be me.

is there something i have missed? or something i should check???

[sergei]

if your S14 has AFM then it might be issue with BOV.
Disconnect BOV and see if you have issues with stalling.
If you are using shit Racepro BOV, sell it and get something like SSQV.
Best way is to get plumback system.
Even beter to put factory BOV back in .

[Mr-Hiney]

Disconnect BOV and see if you have issues with stalling.

isnt that bad for boosting???

If you are using sh1t Racepro BOV, sell it and get something like SSQV.

good GOD no!! its a genuine Blitz one

Even beter to put factory BOV back in .

i may (or may not) have just thrown that out

[sergei]

I am not saying to run all the time without BOV. BTW there are a lot of factory cars that do not use BOV at all.
The problem might be in either BOV open on off throttle for too long or never completly closed, or your ECU cannot cope with BOV bypassing too much air.
With AFM when you have atmospheric BOV, the bypass air tricks ECU into supplying more fuel than needed - because relative to AFM there is flow (bypass to air) while engine has the throttle shut and very little air going into it.

[Mr-Hiney]

oic, well i'll give it a go and let u know how i get on

cheers dude, legendary stuff

[Mr-Hiney]

well, so far i've cleaned out my AFM with Co2 and it looks perfectly fine.

i've also unplugged the BOV and plugged up the line. it stops doing the whole rev dropping thing, but runs like ass. when u TRY and accelerate it kinda thinks about it for 2-3 secs THEN gives in and accelerates.

i've been told by someone that the spark plugs might be a bit had it....... opinions??

and there was quite a bit of oily and sludgy goodness in my intake pipe between the pod filter and the turbo..... blow back??? or a serious issue???

[MasCam]

I used to have a sr20 powered primera and I know that they were prone to the black sludgey stuff blocking the area around the throttle butterfly causing the idle to go to the pack. There was supposed to be a slight gap around the butterfly allowing a small amount of air through for the idle.

might be worth a look.

Chris

[sergei]

As far as I have seen on SR engines there is an idle control valve of some sort (if it is upright manifold it will be straight on it can't miss it, if it is upside down one it will be under). That valve is responsible to keep the idle where it is, so if it is blocked just soak it with carb cleaner (there will be a hose going to it right before throttle).

[tHE _mEXICAN]

Sorry to hijack this post

The problem might be in either BOV open on off throttle for too long or never completly closed, or your ECU cannot cope with BOV bypassing too much air.

So if your BOV is not completely closed at idle this could cause idling issues? How can you prevent this as on my car it has an adjustment on it but either way it's pretty much open until you give it some throttle and then it opens when you come off boost again.

[tex]

Ask for the "maori" at nisbits and see if he can give you an idea of wat the problem is.

Sounds like a vac leak causing the stalling. Since it is uses a AFM any unmapped air will cause the ecu to compensate.

Also things to consider...

As per sergi, SR's, and in saying that most nissans have a issue with the idle up ACC valve. Round valve on the inlet manifold with brown plug which gets oil build up. Remove and clean with carby cleaner etc. Make sure you seal it properly when you replace.

Check if top end is sluggy. Look under the oil cap. Look at the cams. If cams look black and build up on cap then best check you oil rails in the head before it starts eating the cam lobes. Very common.

AFM don't normally give too many probs on the sr's neither do the cas, unlike the RB equilavlents.

TEX

[sergei]

Sorry to hijack this post

The problem might be in either BOV open on off throttle for too long or never completly closed, or your ECU cannot cope with BOV bypassing too much air.

So if your BOV is not completely closed at idle this could cause idling issues? How can you prevent this as on my car it has an adjustment on it but either way it's pretty much open until you give it some throttle and then it opens when you come off boost again.

Only on vehicles with AFM.