Bad idling

[breitling]

oh the maf house is bigger than original now?
and when you check the original ECU you do it with the original maf,or the modified one?

As you know,my idle cured as soon as i tightened the ECU earth screws on the inlet manifold.Other than that,although the maf is original in my case,and needs to be changed as well,it still holds up well.

Yes its bigger than original and i checked it with the modified one.

My camshafts are also in right position. My tuner told me to make a cross inside the maf housing. If thats not working im gonna try with a new maf unit. Or maybe i need to buy a new tps.

[ur-s4315]

My problem is allmost cured. The camshafts were not correctly installed, markings did not meet. Now the markings are right and the idle is very good, but now I can't get any boost pressure, oly 0.5bar. I think I know were the problem is, my camshaft marking is on the right side and it should be on the left. I will try to put on the left side and let you know.

[A80Avant]

oh the maf house is bigger than original now?
and when you check the original ECU you do it with the original maf,or the modified one?

As you know,my idle cured as soon as i tightened the ECU earth screws on the inlet manifold.Other than that,although the maf is original in my case,and needs to be changed as well,it still holds up well.

[breitling]

I have a cone filter.
Still i have the same problem. Tryed with another ecu. Another chip.. still the same.

But when i connect the original ecu it runs flat on 3000 rpm and up..

Can it be because of the 3,5" maf house and the bigger injectors ? I have the orange 550cc.

Soon im going mad!!

[A80Avant]

i mean,did you use the RS2 air filter too?
or did you go with KN filter cone?

[breitling]

Yes its odd...

Im sorry but i dont have any pics of the maf.. its just a bigger pipe. looks like the original.

[A80Avant]

hmmm...that is odd....what could the ecu remap has to do with this idling problem?
Also breitling,could you send me a couple of pics of your MAF setup with the airfilter(vasilis3690@gmail.com)

[breitling]

Today i have tried with another RS2 ECU box. Original box with original chips.
The idle is stabile and steady. Hmmmm

[breitling]

Breitling,it seems that my MAF although indeed has a problem,the problem in my car was the 2 bolts on the inlet manifold where all the earth cables connect from the ECU.Since i tightened them the idle went back to normal,i have very good fuel consumption again,no black smoke.and only a 561 fault code which i suspect is from my fuel filter cause my fuel pump is also a bit louder than it should be.Check if the bolts are loose and also check the MAF again.

Hmm.. i have checked the earth but will do it again.
I will also try another ecu.

[ur-s4315]

I have tried another MAF from a rs2 which has no problems. I have also checked the earth connections. Tomorrow I will measure the camshafts.

[A80Avant]

Breitling,it seems that my MAF although indeed has a problem,the problem in my car was the 2 bolts on the inlet manifold where all the earth cables connect from the ECU.Since i tightened them the idle went back to normal,i have very good fuel consumption again,no black smoke.and only a 561 fault code which i suspect is from my fuel filter cause my fuel pump is also a bit louder than it should be.Check if the bolts are loose and also check the MAF again.

[breitling]

Any updates??

[220bhp]

Throttle position sensor. the little black box on the back of the throttle body

[A80Avant]

yesterday after leaving the car at the garage from a small drive the day before,i went for another easy drive.The car did some very bad idling.The needle was jumping up and down while the ecu was trying to keep the car from stalling.I burned a whole lot of fuel smelling all over the place.

Today i did some checking.I dont know how to use VAGCOM very well,but from there i got no fault codes at all!Not even when the car was behaving in this erratic way!!.

SO i changed the MAF!!! why?it was the only thing that i had recently changed along with the WGFV.The WGFV has nothing to do with idle,so it seemed logical that it should be the answer,although it was a new unit bought from vagparts a month ago,but only been used for a week since i was away for the summer.

the car now behaves perfectly and everything is back to normal.I took the time to clean the ISV as well,although it was perfectly clean already when i got it out,so no problem there.

I do believe that sometimes the temp sensors could produce false readings that mess up the idle,but in tuned cars my mechanic thinks that this MAF is one of the first things to go!

so give a check on the maf once again..it may cure things...

[breitling]

Had a very similar problem with revs jumping up and down on my s2, turned out to be a faulty tps.

What is TPS??