Jay Wellwood

I'm hopeful that someone can confirm my suspicions (sp?).

Patient - 87 S4 Auto

Maintenance performed -
-Intake removed and re-painted.
-All gaskets replaced (throttle body to Intake, Intake to heads, and
Intake side panel to Intake main body).
-Idle/WOT Switch replaced with new one and set to open the Idle switch
when the go pedal is just depressed.
-Idle Stabilizer replaced with new one.
-Injectors cleaned and flow balanced by a reputable source.
-Replaced Temp II sensor with new one.
-MAF cleaned VERY carefully (removed inlet/outlet screens and cleaned the
screens ONLY - all wires are intact).

Results-
-Car starts fine.
-With LH Unit 1 - idles high (~2500 rpm) and cycles between 2500 and 3000
rpm. No flappy 'wave' when ignition is initially turned on.
-With LH Unit 2 - idles ~1000, cycles between 1000 and 1500 with abrupt
cycles (i.e. on/off fuel source - forgot to check Flappy for wave).

Checked-

-Swapped LH Units (see above for results).
-Flappy for free movement, and used the Mitivac for verification that the
vacuum Pod/Lines were intact - no problems noted.

My 'gut' feeling is a masked false air signal (for lack of better terms -
air is getting by the MAF without it 'seeing' the air).

Anyone?

Geez...and the Intake looks sooooo good too. Talk about frustration!

Oh yeah - looks like I may have to perform some thread repair on the bolt
that holds the heater valve tot he head - coolant leak, and no thread
tighten. Dammmmiiitt!!!

I realize that this is a shot in the dark - but it beats scracthin' my head
alone.

TIA-

Thom1

Hi Jay,

I am not sure what you mean by LH units 1 and 2. But, if you are saying that your idle speed is too high, it could be a leaky intake. You can pressurize the intake to check for leaks.

You can probably cure the thread leak with high temp, sensor safe, gasket sealant smeared onto the bolt and tightened.

Good Luck,
HTH, <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Jay Wellwood

Thanks Thom-

LH Unit 1 & 2 refer to the LH units I have - a primary and a backup. Both less than a year old.

I did pressurize the Intake - no leaks. Hmmmm.....disconnected the MAF sensor - noticable difference = MAF is at least functioning as designed.

Spent the last 5 hours pulling and re-installing the Intake and double checking all connectors/vacuum lines - oh and fixing the coolant leak (heater head port inboard port released 3 threads from the head - oops. Fixed - no coolant leaks now).

Car now idles ~1600 (or about 1000 too high). Idle is very smooth (albeit too high), and the throttle is responsive to blips.

On a side note - my Flappy valve doesn't 'wave' at me - I'm beginning to think that the two are related.

If anyone else has BTDT - or has any other potentially useful info - let me know.

TIA-

SHunter

Jay,

Just a shot in the dark but maybe your idle stabelizer is stuck. If your flappy valve is not moving on its own but is free sounds like a vacuum leak.

S.Hunter
cyber5-0@swbell.net

BTW: Was not at the last meeting because I was on drugs due to having wisdom teeth pulled

Jay Wellwood

Hey Steve-

Thanks for the input. When I re-pulled the iNtake yeaterday, I replaced the Idle Stabilzer with a new one. I think that might be why the rpms dropped.

Still don't know about flappy lack of waving. Will delve into this again today.

<img src="confused.gif" border="0">