Jump to content
SAU Community

Boost Gauge Casuing Idle Hunt?

ARTZ

By ARTZ,
in Engines & Forced Induction

 Share

Recommended Posts

ARTZ Grand Master

ARTZ

Posted
Posted

Ok just a bit curious here...had an idle hunting problem for ages now, ever since I got car tuned actually....Trent offered to fix it for me thinking it was a tune issues but I never got around to it...

Now by accident I blocked of my aftermarket (garrett) boost gauge line...and magic...Idle problem has dissapeared...

there is a t-piece of the manifold so original dash gauge was working as well...the hunting would normally appear on decel..and was bad to the point is was trying to surge me into corners...then on pulling the car up it would bounce from 2000-500rpm then usually eventually settle..after anything from 10sec to 2 minutes....

Now it is settling to about 1200rpm on pullup then settles to just under 1000rpm somewhere....does this seem more like normal behaviour?

I cant find any leaks or anything in the line and I am quite happy to ditch the shitty gauge anyway..

but does anyone know why it would cause this?

:cheers:

Link to comment
https://www.sau.com.au/forums/topic/435910-boost-gauge-casuing-idle-hunt/
Share on other sites
89CAL Grand Master

89CAL

Posted
Posted

Yeah but MAP sensor will still read manifold pressure. If there is a drop in manifold pressure, the map sensor will react to it. Or should do anyway.

You could chuck a wideband on to see if there is a change in AFR when it happens though. I highly doubt it would be dropping MAP to a point where it would cause an issue but stranger things have happened.

ARTZ Grand Master

ARTZ

Posted
  • Author
Posted

I didn't disconnect anything or touched anything else in the engine bay for that matter and they are on completely different lines...MAP is connected to fuel reg vacumn, boost is off the back of manifold.....its definitely this gauge thats caused it....when i put my boost gauge back in a few weeks back I accidentally plugged the line onto the bolt instead of the nipple (must of been dark)...effectively plugging it up...just noticed my boost gauge wasn't working yesterday and put 2 and 2 together...but why is it affecting it now I have MAp and not when I had Afm? I wonder if because the stock boost gauge is hooked up and still reading, its digital not mechanical yeah...i will try disconnecting it and see what happens..

and yeah there was a change in AFR..its just like it was hunting for an idle , cause eventually it would settle to idle...but in the meantime it was rich/lean/rich/lean

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • djr81
      R32 update from 1990's spec.

      By djr81 · Posted

      New CAS just turned up from NZ Wiring. Looks like a nice bit of gear.  So, yeah. Triggered, bro. Realised I may as well do the cam belt while mucking about with it so will order one of them.
    • MBS206
      Duncan's V37.......race car?

      By MBS206 · Posted

      Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • RP1421
      S15 Spec R

      By RP1421 · Posted

      As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
×
×
  • Create New...