SpAm@FC

iTrader: (4)

Hi guys

have my FC TII S4 since 2 years and cant get rid of my IDLE Problem...

i've a new AFM, a new and correctly setted TPS, new grounds on the engine...

so, my problem is a little bit strange

when i start my engine in the morning (cold) i have my coldstart idle @ 3000rpm and after a short time or when i put the 1st gear in it drops @ 1100 rpm (ok)

now i drive to work, let the car sit and come back, start it, sometimes i have coldidle sometimes not... when i have it the 7en won't hold the IDLE for a long time

when i get into a shop or something and let the 7en sit for a few minutes he wouldn't hold his IDLE after the next startup

BUT

when he don't hold IDLE then i can "bump" the IDLE up... so i wait for dropping the IDLE to 200rpm, press the pedal, let the engine rev u tu ~1500rpm for a half second, IDLE drops down on 200rpm ... when i do this several times the 7en holds the IDLE perfectly... but only for a few kilometers... then i have to play the game again...

it really bothers me... i HATE it really *mad*

what can it be? maybe the WaterTempSensor for the ECU? any other ideas?

pls give me any input you can give

thx 4 answers

HAILERS

A malfunctioning BAC and or a misadjusted fast idle cam/thermowax. See the FUEL section of the online FSM for how to set those items.

The idle should have been set with something called a Initial Set Coupler installed and then the idle set to approx 750. After that you pull the initial set coupler back out. That causes the BAC to return to its normal duty cycle.

The BAC with the Initial Set Coupler installed will have a FIXED duty cycle of approx 45percent. They do that to the BAC so that when you make adjustments to the idle, the bac won't try to undo/effect your adjustments and cause you to have a hissy fit.

BAC's are good. Lack of BAC's are bad.

SpAm@FC

iTrader: (4)

ok, so i will (double)check the following things this week:

IDLE Speed Adjustment
IDLE Mixture Adjustment + variable Resistor testing
Hot Start Assistant System (Whater Thermo and Intake Temp Sensor)
Pressure Regulator Control Solenid Valve
BAC Valve
Air Bypass Solenoid Valve
Air Supply Valve

i havent' found some good stuff about the fast idle cam / thermowax system...? also to find in the FSM? (will check it out tommorow)

any other inputs / things to check?

SpAm@FC

iTrader: (4)

soooooo, i have NO AVC leak...

i've sprayed a full can of starter-spray ontp my engine bay, espacially under the Intercooler, and nothing ...

but...
when i disconnect my BAC Valve (2 pin connector), the IDLE should drop about ~100rpm, right?
when i disconnect my BAC Valve, the Engine dies... *eek*... pleas help me out

HAILERS

[QUOTE=SpAm@FC]soooooo, i have NO AVC leak...

i've sprayed a full can of starter-spray ontp my engine bay, espacially under the Intercooler, and nothing ...

but...
when i disconnect my BAC Valve (2 pin connector), the IDLE should drop about ~100rpm, right?
when i disconnect my BAC Valve, the Engine dies... *eek*... pleas help me out [/QUOTE********************************************* ************************************************** ************************************************** *******************************************

There is the problem. The BAC is carrying the whole load. It should not. You need to start from square one following the fsm.

Install the initial set coupler.

Set the timing with the rpms close to the 700-800 range, but 500-900 will be fine for setting the timing IF the initial set coupler is installed.

THEN adjust the idle with the initial set coupler still installed. Set it as close to 750 as possible.

Now set the tps. Preferably with an output of approx 1vdc with a HOT engine idling.

It's not my fault nor yours if someone has previously meddled with the throttle stop screw, afm, whatever.

It is GOOD news that you BAC is alive and well to some extent.

Many idle problems with a turboii are related to the turbo inlet duct at the turbo. That end likes to crack and leak air. It's hard to spray starter fluid there with the engine idling. It can be done though.

A wothwhile site: http://www.teamfc3s.org/info/articles/idle.html

SpAm@FC

iTrader: (4)

Hi!

Thanks for your answers, but i'm a little bit confused...

how should i set the timing? with the CAS? if yes, howe should i do that with an running engine? i think i don't understand an essential part of your post :/ sry, english is a foreign language for me

also with the TPS... how should i set it with the running engine? i have to take of the intercooler to get to the TPS settingscrew!?

im a little bit confused right now

but big thanks for all your great help here on the forum

driftin8ez

is it me or is it kindof dangerous to spray starter fluid all over your engine. Try using carb cleaner next time. Will still make your engine react if you have a vac leak and you wont blow up will doing it. oh ya and youll be cleaning your engine instead of setting it on fire.

theman4444

Starter Fluid BAD!! Carb Cleaner and Nonclorinated Brake Cleaner GOOD!!!

SpAm@FC

iTrader: (4)

lol very cool... i've talked to the store.owner, and he said i should use starter spray instead of carbcleaner loool... but no prob, i always have a firing executer by hand if i do such things like spray anything onto my engine or do anything with the fuelsystem safety first

so, a little update...

i've taken out the complete induction funnel + airpump, so i see on the turbo...

1.) there is a line which goes to the turbouhousing on the intercooler - side... i think thats the VAC line for the wastegate right? where the line hits the turbo, there is a metall nipple which i can move in and out of the housing... bad, doesn't matter or normal?

2.) I've checked some valves.

BAC valve, Air Bypass Solenid Valve and Air supply Valve ... they are all in the meassuring tolerance...
BUT...

my Variable Resistor...
there are Three Terminals, A, B, and C... i've checked the Resistor like said in the FSM...

Between Terminal A and C i have NO readings
Between Terminal B and C i have 4,81 kOhm Resistance... the FSM say that the reading should be between 0,05 and 4,5kOhm...
so, the resistor is dead... is THIS my IDLE Problem? (hope to see a positive answer )...

3.) On the Air Intake Funnel, there are 2 holes... one comes from the stock BOV (blocked off cause aftermarket) and in the other hole there is a check valve which lets air trough only in one direction... in which direction should the arrow show when the valve is assembled? to the air filter or to the line?

thx 4 your answers and your time

HAILERS

********8how should i set the timing? with the CAS? if yes, howe should i do that with an running engine? i think i don't understand an essential part of your post :/ sry, english is a foreign language for me***************

Using a timing light attached to either of the LEAD wires and turning the CAS until the first mark on the pulley aligns with the fixed pointer on the front cover.

******************also with the TPS... how should i set it with the running engine? i have to take of the intercooler to get to the TPS settingscrew!? ************

I use a three foot long common screwdriver. Taking care not to touch the alternator battery terminal when setting the tps.

The Initial Set Coupler is a Green, two socket connector located near the engine fuse box. You take a piece of wire bare at both ends and insert the ends into the two sockets of that coupler. When you do that the ECU sets the BAC to a fixed duty cycle of approx 45%. That means when you go about fiddling with the air adjustment screw the BAC will not react to your adjustment by trying to up/lower the idle as you fiddle. I THINK it also keeps the ECU from advancing the timing as you make adjustments on the engine.

I use starter fluid to find leaks. Always have. What? Me worry? Oh, and I like that term Fire Executer. Beats fire extinguisher.

I didn't notice you were a Austrian earlier.

SpAm@FC

iTrader: (4)

Hi Hailers...

thx 4 your help

but theres another point... how do you meassure the V of the TPS while the engine is running?

btw... lol @ fire executer

do you also have answers on my questions above? (Variable Resistor, check valve, nipple in turbohousing...)

edit: check valve already found on a picture


thx

HAILERS

About the variable resistor: What they want you to do, it turn the screw all the way one direction and then look at the resistance on A-C then B-C

The measurement on B-C should read about 4.5 when the screw is to the full rich position (fully clockwise with the screw). The measurement at B-C should be approx .5K ohms when you turn the screw fully to the lean (counterclockwise direction).

The A-C should read just the opposite of what you read when reading B-C. Make sense??? Yeah.

When my car is fully cold and I pulled the plug off the variable resistor (car idling), the engine stalled.

After warming the engine up, I can pull the variable resistor plug off and the engine will stumble for a moment then idle somewhat normally.

Try ohming out B-C and then A-C but this time turn the screw from one end to the other while looking at the meter and see if you now have a reading at A-C.

If A-C never gets off zero, then I'd pull the plug on the variable resistor. When you do that the ECU goes to a fixed reading or to a default if you will.

The answer is YES, the variable resistor can effect your idle.

Your variable resistors screw should only turn about 3/4 of a turn. There are stops on each end.

SpAm@FC

iTrader: (4)

thx hailers!

i will check this immediately! will post in ~10mins

i HOPE that its the fu**ing wrong part in my car

HAILERS

I measure the voltage of the tps output at the ECU with the engine running. That is a awkward way to do it I suppose.

Another way is to patch a wire into the back of the green/red wire of the tps connector and make its length long enough so you have access to it with the intercooler on. Maybe put a connector on the end, like a female connector with insulation around it. I did that once as a temporary method.

Or leave the engine off and just warm up the engine and remove the intercooler. I don't know if you noticed, but on the aft left side of the throttle body there is a mushroom shaped damper. If you crook your finger under the fast idle screw and lift up, the throttle linkage will come off something called a fast idle cam and the linkage for the tps will now be where it should be when the engine is fully hot (whether the engine is hot or cold when you do that).

That last paragraph probably did more harm than good. I was trying to say that even if the engine was stone cold, you could lift up on that fast idle cam and the linkage to the TPS will now be where it will be when the car warms up. Therefore you could set the tps at that time, and it will be right even after the engine warms up.

That loose right angle, metal nipple is for the wastegate actuator. If it does not fall out in you hand and you can pull on it and it won't fall out, I'd leave it alone. Maybe put a bit of epoxy around it to completly seal it. That sounds like a minor problem.

SpAm@FC

iTrader: (4)

thanks 4 the input

ok, so i will do the connecter method + custom very loooong isolated screwdriver ... sounds nice

back to the variable resistor...

i've took the blindcap off and... what the hell? there is no screw!!! i cant do anything with this resistor because i can't turn it... that don't looks normal!?

HAILERS

This

Jumbogumbp

lol... I thought the same thing with mine... figured out that there was a bunch of gunk built up ontop of the screw... after cleaning I was able to see the screw... maybe thats why you can't find it?

SpAm@FC

iTrader: (4)

this is my variable resistor...

no screw *eek*... replace it?

X-JaVeN-X

^lol that sux

SpAm@FC

iTrader: (4)

so what do you think?

replace that ****?

Jumbogumbp

wow that does suck... I'd replace it.

SpAm@FC

iTrader: (4)

ok, i've found a cheap used one with good measurements...

will be back when i got it shipped and installed

big thx 4 all your great help!

HAILERS

The parts fische for the USA models use a different number than the one on your Variable Resistor. It could be a European Spec engine uses one with no screw. I'm just guessing. It'd take someone with a European Spec to tell us what they have.

SpAm@FC

iTrader: (4)

wtf? no screw = stock?

don't think so... it should be a variable Resistor, not a Resistor

when i look close to the "screw", i think that somebody had broke the head from the bolt :/

but i already have a new one, waiting to be shipped

SpAm@FC

iTrader: (4)

i start to HATE my rex... im really going mad and crazy *arrrgh*

so..

i've attached a connector to my TPS...

first, i've setted the TPS with the intercooler off and cold engine @ 1.0kOhm
ok, i've put all together again... started the engine... PERFECT idle for a few seconds, then the same **** like before... sometimes he hold IDLE with a little jumping, sometimes he dies, sometimes the IDLE jumped like crazy...

so ok... then i've checked the resistance of the TPS while the engine is running... the readings where really crazy, nothing like in spec *grrrrr*

when i shut the engine off and read the closet throttle, i've got a reading of 0.77kOhm and when i open the trhttle i've got readings under 0.5kOhm...

so ok, then i've bridged the Initial Set Coupler and again, i got wired readings from the TPS..

i only get good readings (between 0.5 and 6 kOhm) when the TPS is NOT connected!

when i bridge the Initial Set Coupler and turn the Screw on the BAC, the IDLE DON'T change... only, when i turn the screw too often, the engine dies... but i never get a stable IDLE or get a "high" IDLE over 1100rpm...

its really crazy, i've tried much more combinations, Settings of TPS and BAC, with or without Initial Set Coupler and i NEVER get a stable IDLE...

i HATE the IDLE system on this car... it drives me crazy as said above...

any inputs, comments, tipps?... i think i will change the BAC...

TPS and AFM is "new" (used and good) by the way

pls help me out