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N42/vacumme/idle adjuster questions

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Old Oct 13, 2007 | 09:40 PM
  #1  
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N42/vacumme/idle adjuster questions

ok, got my car back together and started it up, i put in the idle asjustement screw with out the IAC valve, and i can get close to a 20 inHG with a little throttle, but at idle it drops to 12-15 and just idles really low and rough, any pics on how you guys did yours? cause i think mine is wrong car would be perfect if it werent for that. i had the stupid manifold with the idle screw that had a T fitting to the IAC adn then down to a little wierd tower thing uner the manifold, but i took that out and have the adjuster screw one end th the throttle body where it was originally connected and the other side straight to the hole that is on the J-pipe.... i thought that woulda been right but i think im wrong so pics or suggestions? i dont think i actually have a vaccume leak but idk. ill try to get a pic up of what im talking about
Old Oct 14, 2007 | 09:26 PM
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seriously? no one? not a single input on this? god, let me go get pictures then. noobs

EDIT: k here are pics and explanations. tell me whats wrong lol.

here is the old intake manifold, circled in red is the mysterious part, wtf is it for? circled in yellow is where the hose connected to it and the other end to the J-pipe, ran fine that way. and circled in blue is where the idle ajustment screw was mounted and connectected to that tube the other end had a tube that went to the throttle body after the butterfly valve so it emptied directly into teh intake manifold.





here is my dads TB with the built in idle adjust ment screw where i got my idea from, cirlced in red is where it took air from infront of the butterfly valve arrow in red is where it emptied that air behind teh butterfly valve, and circled in green is teh adjustment screw, simple no?




here is the N42 on my car




here circled in blue you can see where the one end of the tube is connected to the J-pipe aka the air infront of the butterfly valve





here is the idle adjuster. red arrow points to the tube that goes to previous picture or the J-pipe. blue circle is the screw adjuster. and the arrows in yellow show the tube on the other end of the adjuster that then connects to the TB stock spot the opening behind the butterfly valve aka directly into teh manifold





here is the TB connection. red arrow points back towards the adjuster, green cirlce is teh connection point, and yellow arrow is where the brass tube goes into the TB behind the butterfly valve aka into the intake manifold.











this setup should work according to my dads TB/intake manifold, and is a simplified version of my stock setup but eliminating the air regulator and that wierd thing i circled in the first picture. and if i hold an ever so slight amount of throttle down the car idles around 1300 and reads about 18-19 inHG but at normal fully closed throttle it acts like its cammed. it idle surges, idles to low, and has only about 12-13 inHG of vaccumme. so wtf did i do wrong? what did you guys do? until this mod the car idled normal. this is driving me crazy. let me know.... HURRY!!!!! need to drive/sell car

Last edited by snwbrderphat540; Oct 14, 2007 at 10:03 PM.
Old Oct 14, 2007 | 10:10 PM
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Why did you remove the air regulator? Have you hooked it back up to see if it idles differently?

This is why I haven't installed my N42... too many probs. I've only seen megasquirt (or similar aftermarket fuel management) setups on turbo motors when using N42.
Old Oct 14, 2007 | 10:20 PM
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ARGH!! r u serious? i thought you did hook urs up?
Old Oct 15, 2007 | 09:56 AM
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I will install mine eventually... but I will remove everything from the stock manifold & get it to run right, BEFORE installing it. Put the stock hoses back on, get it to run normal, then take off one hose / connection at a time.

If you take everything off all at once... you get a nice headache trying to figure out which piece you should have left in.
Old Oct 15, 2007 | 10:57 AM
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its just so dumb, it is doing the same exact function as before, and if i unplugged the air regulator it ran fine so i know thats not needed, stupid stupid stupid! and i searched hybridz and crap for an answer, and nothing, only "will this fit on the turbo motor? durrrr" i cant believe there is no one out there that did an N42 swap on the stock electronics.
Old Oct 15, 2007 | 02:12 PM
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I'm sure someone has... they just made sure everything will still work.

Now go put all the hoses back together how they should be!
Old Oct 15, 2007 | 03:33 PM
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well, i was foolin today, and just upped the idle a smidge, i think i just have a genuine vaccume leak somewhere. cause the idle adjuster actually works fine..... soooo ill need to get a can of carb cleaner and go vacumme leak hunting. if that doesnt work then ill tare back into the motor pull the manifold and see whats up
Old Oct 16, 2007 | 09:42 PM
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i drove it today! and it drives like pure ****. so im going to switch manifolds or try to get all the air regulator stuff switched over, but i dont see how thats going to work. it does however sound different with this manifold and VERY VERY sweet. turbo you can hear spool so good, and the exhaust note even changed a little. or that could be from the new gasket. lol. idk, i just dont want to switch back after seeing this clean look but i guess im gonna have to
Old Oct 17, 2007 | 07:02 PM
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just hook your air regulator back up and run it like that. if it solves the problem, then your idler setup is faulty. and you need to rework it. i disconnected the air regulator from my Turbo manifold and just plugged off all open lines. It runs like seven shades of **** if its cold, but once it warms up it runs fine. idles a little lower than normal though. i didn't like it being crappy at the start so i put it all back on.
Old Nov 5, 2007 | 10:27 AM
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Hey question, i have a leak around the first picture snw posted. the area circled in red, it's like leaking coolang i believe, or SOMETHING around there is leaking coolant....And i can relate with the rough idle, this afternoon i will change my PCV valve but i'm pretty sure i have a vacuum leak somewhere, but i don't know where...
Old Nov 5, 2007 | 06:32 PM
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they run coolant around the throttle body so try to hunt down the leak. also, my rough idle is timing issue. its fudged up... super gay.
Old Nov 6, 2007 | 06:47 AM
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Originally Posted by snwbrderphat540
my rough idle is timing issue. its fudged up... super gay.
What is your timing set to?
Old Nov 6, 2007 | 08:33 AM
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30 degrees, its the only way the car will rev up at WOT. other wise it goes up to around 3-4 grand and start sputtering stumbling and back fireing. the timing is NOT advancing like it should. im going to try the TPS now since i tried a new distributor. if thats not it. gonna have to try a new ECU.
Old Nov 6, 2007 | 09:26 AM
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Have you tested the CHTS at all? I kept having similar problems, but it was related to the ECU wiring, the ground wires weren't grounded properly, or corroded, something to that extent which kept giving me trouble. thxone had the same problem, as I believe Nismopick had a similar problem, once I regrounded my ECU's harness in the engine bay it seemed to solve my issues.
If I'm not mistaken I remember thxone saying he had advanced his timing all the way and that seemed to fix his problem, but it wasn't until he put the timing back and messed with the wires that it seemed to run the way it should.
Old Nov 6, 2007 | 09:46 AM
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you know... i really should check my grounds.....
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