1dirtyZ

iTrader: (1)

i just had an idea.... what do poeple with huge cams and NO F/I do when they encounter this problem??

MIGHTYMOUSE

iTrader: (59)

has anyone tried setting the tb open further manually via the setscrew.. sounds like your iac is getting wacked out with the airflow, just take it out of the equation... actually, do the same with the pcv and that wont mess with you either.

im going to have a look at azzhaulers ati this weekend, hes having the same problems and i intend to fix them if i can.

keep this stuff in mind.
1. keep boost (discharge side of head unit up until throttle body) away from the pcv line, you can do this by installing a check valve so it only see's vacuum, and/or move the vaccum source to somewhere after the maf but before the head unit.. then the air will be allready metered when it eventually gets thru the crankcase to the intake right side port.
2. only discharge unmetered air.. if your bov is before the maf, it can vent to atmosphere or route back into the system, but only before the maf(as in before the head unit) if the bov is after the maf, the air must re route back into the system, before the head unit but still after the maf.
3. if metered air does not go in to the intake from the tb or pcv line.. then you will go rich. if unmetered air goes into the intake, you will go lean. if unmetered air does not go in to the intake you are fine, same with metered air going into the intake (thats the idea).

maybe that will help?

also, check vor air leaks everywhere, blown off hoses etc.

1dirtyZ

iTrader: (1)

hehehhe, we're waaay ahead of you mightymouse!

i did mess with the idle screw and the IAC, you have to remeber if you lower your IAC count to under 15 i belive it will set a code. i tried screwing it in all the way ( till the throttle body blade binded shut)and tried with no luck raising the idle up ( lowers you IAC count = SES)

as for your suggestions,
1- i don't have a PCV system!!
2- bov is behind the maf and maf is infront of the head unit.
3- checked for leaks and unmetered air coming in , but nothing there.

the thing i notice is that the car does not die if you blip the gas just before the rpm hits idle, it might surge a bit but usually it recovers.

isn't there a IAC follower table in ls1edit, maybe if anyone knows anything about it the could tell us how to make the IAC motor open up upon rpm drop to simulate a blip in the gas???

mightymouse , if you find anything, PLEASE tell us about it!! you'd be doing us a huge favor.

Cool28

iTrader: (2)

ok let me see I Get ya you screwed it open more the TB right? Way it sounded was like u closed it more at idle. When I first got my turbo kit install I had to open the TB at idle more to have it idle the same. Then when I moved tubing and un kinked some hoses I had to close the TB more cause it was idling higher.

1dirtyZ

iTrader: (1)

i did both , i screwed it open and closed.
i'm leaning towrds the maf location theory.

JAS

Are you running MAF ends or stock MAF with stock table?

If you are leaning towards the MAF location theory, then why don't Vortech users have issues or others?

White_Hawk

iTrader: (3)

I am runnning a relocated MAF - right in front of the intake to the blower on my PD. I did have a problem that I traced to an extension cable I used to reach the new MAF location. I had the 6' and when I switched to the 3' extension the problem went away.

Good luck and keep us apprised.

-Geoff

MIGHTYMOUSE

iTrader: (59)

1 dirty.. does your bov vent to atmosphere?

just for fun, unhook the bov and see how it runs.. it wont hurt anything.

1dirtyZ

iTrader: (1)

jas , i'm running the stock maf with the screen in .

mighty mouse , i had the BOV venting into the atmosphere when the maf was in the stock location. didn't help much but sure made the "WOOOSHHH" noise louder.

i talked to of all people , a redneck / hillbilly mechanic that worked next to my buddy's tranny shop. i told him about the dying after wot problem and he said " yer poblem here is caused bey this here eye-ak moter ( IAC), yer pintle is getting all kidsa stuf 'n gum buildin' up on it that when yer standin' on it the moter pushes that pintle shut and as soon as yer lettin' off the pintle stays stuck shut."

the strange thing is that when i got home , i unpluged the IAC and guess what , it was covered in this sooty gooey stuff. so i clean it off and put it in and the car wouldn't idle when i started it , so i raise the idle maually ( screw) and it surges a while and settles. i still didn't take it for a test drive to see how it worked , but it looks promising!!

shows you how you never know who knows what !

JAS

<img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Don't you just love it when you change something and something else comes up?

Let us know how it turns out, ultimately your the one that knows the most about your car so we can only throw out ideas.

1dirtyZ

iTrader: (1)

hehehe, yeah i know what you mean.
well it doesn't seem like that made a difference.
i bought some accordion tube to cut up and install the maf on to. i'm hoping this helps.

02BlackWS6

Well i had a TR224 cam and S2 heads in my car before i switched to a smaller setup. With my car being a A4 and the TR224 the only way to get rid of the surging was to raise the idle speed to 900rpm. Plus i'm sure Ed Wright knows how to tune the idle circuit for bigger cams and big torque converters. I have a question...does the 5# ATI kit come with bigger injectors and tuning if you have heads/cam done to the car? I could see my car running a tad lean even with the 5# pulley which probably would only show about 3#'s because of my heads/cam. Or is the tuning and injectors extra?

1dirtyZ

iTrader: (1)

i'm not sure but i think it doesn't come with injectors. what it comes with is an extra fule pump to boost the pressure up so your injectors flow even more. though you might want to check up on that cause my info is ancient.

cdk4219

Disconnect the BOV and plug both ends. Start the car and see if it will idle.

1dirtyZ

iTrader: (1)

don't get me wrong , but why on earth would i want to do that?

cdk4219

It seems to me that the probable cause for the rough idling condition is the introduction of non-metered air into the intake tract. The BOV in my opinion could be the cause of this problem. It is my understanding that the BOV is plumbed back into the intake duct of the Procharger. I believe this is because at idle the valve doesnt close all of the way, letting in air. If it were plumbed to the atmosphere it would pull unfiltered air, but as it is with a pull through MAF you may have created a leak in between the maf and the manifold. I might be way off base, but all the problems you describe, and what modifications you have made right before the problems. It seems like the problem is worse after full throttle runs, when the BOV opens up and releases the pressure, but the MAF is still reading this air that the blower is sucking in, probably creating a rich condition that wont let the car idle.

JAS

? Since the ATI bypass valve recirculates from aft blower to pre-blower like the Vortech kit does and not to atmosphere, what do you see as being unmetered with the MAF relocated pre-blower right after filter?

You have:

Stock LS1:
Intake/TB <- FA <-MAF <-Filter

Stock ATI:
Intake/TB <- MAF <- Plenum <- One side bypass valve <- Dual intercoolers <- Blower <- FA <- bypass valve return <- Filter

Relocated ATI:
Intake/TB <- Plenum <- One side bypass valve <- Dual intercoolers <- Blower <- FA <-bypass valve return <- MAF <- Filter

With stock ATI setup you can bypass valve to atmosphere since it's not metered. But the FA is unmetered.

With relocated your bypass valve return and recirculates since it's been already metered and the FA is metered too like pre blower Stock LS1.

Did I miss something?

1dirtyZ

iTrader: (1)

jas, excuse my ignorance but what do you mean by "FA"???

cdk4219, the ATI set up does indeed plumb the BOV back into the blower intake hat (or track).
you mentioned unmetered air if the bov was vented into the atmosphere, but i have something to add, on the stock ati set up if you vent the bov to the atmosphere it all happenes before the maf , so it isn't metered yet and air does not get sucked in the bov from the outside in because of the pressure that's always present in the tubes.

now,my understanding is at idle the bov valve is open ( flows air back into the inlet hat of the blower) due to the vaccumm it's seeing. under load (WOT) there isn't much vaccume and the bov valve is shut. i was talking to a friend of mine who knows his way around turbos and he said something to the tune of the bov should be CLOSED at idle. and only opens up when letting off the gas.

i seem to think of two possible causes now;
- the bov pushing so much air when i let off WOT that it's blowing back into the maf and causing a wrong reading.
- a faulty BOV .

i'm going to tinker around with the maf location tomorrow as well as try to plug the bov holes to see how well it idles and see what i get.

sorry for the long post <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Black LS1 T/A

1DirtyZ...

Check your Purge Valve and see if it is stuck after a couple WOT runs... mine did that twice.

I wonder if the new MAF position may be slamming the Purge Valve harder, for some reason. I'm not saying it is, I'm just throwing that out there.
Reasons why that's not possible would be cool, and reasons it MIGHT happen are, too. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Check it after you get the stumble... probably a blast thru 1st gear, then drop to idle.

It would be interesting if suddenly 1DirtyZ is getting a stuck Purge Valve, too.

JAS

FA = Fresh Air (Passenger side front valve cover crank fa) Stock it goes to the TB, ATI it goes from the valve cover to the blower inlet hat.