Okay fellas I have a hesitation question.

[hostile]

Question for my freind regarding his 95 TSi AWD.

He is having hesitation at WOT. He say the car shudders and slams and loses power. Regardless of boost. His car also runs bad until it is warmed up.


He had a SAFC installed in the past but it was "Taken out" Is there any way they could have messed up taking out the afc?

Also he is running a big 16g, RC 550's, MBC, 3 inch exhuast, No cat, Nology Wires, And iridum plugs factory gap.

I am questoning the AFC uninstall because we were using some of the old wiring from the AFC when we installed a NX kit and it seems like some of the problems came right after that.

What wires are in the afc harness and where do they tap. If one was disconnected what adverse effects could it have.

 

[candela]

Well some or one of the wires neds to be cut to the ecu i think when installing the afc...bu tthe probably is most likely the injectors. With those 550's and no fuel controller the car will run way rich and stutter and hesitate just like you say. Why would you take out the afc? Youll either need some other form of control or youll have to run the stock injectors if you want the problem to stop...

 

[hostile]

Well the guy who installed the AFC for him has never installed or tuned an AFC.

He used the setting of RRE and he wasn't happy with it so he took it out.

I think we are goign to go through and re hookup the AFC.

With this setup I should start out negative on all the settings?

I have never tuned an afc either but I am a little more electroniclly inclined than him.

So we will see.

BTW can I just tap the blue wire and read voltage from the o2 until we get an af guage?

What is considered good volatges across the rpm band

 

[fast4wardTSi]

White wire on AFC = airflow signal input from MAS to AFC
Yellow wire on AFC = airflow signal output from AFC to the car's ECU
Green wire on AFC = engine RPM signal
Black wire on AFC = ground (must be the same ground that is used to
ground the ECU to the car)
Red wire on AFC = main power to AFC unit
Blue wire on AFC is for twin turbo only. Insulate it.

There are many thing that could go wrong if some of the wires comind out of the ECU pin are touching or the insullation has came off. If your buddy is running 550's with no fuel control, then yes the car is going to run crazy rich all the time at low throttle and probably at WOT as well, depending on the amount of boost/fuel pressure he is running. To tune the AFC on the car at idle, view the fuel trim low. View the mid and high at higher throttle positions.It should be around 100% +\- 10%. It is probably really low with the 550's. You will be leaning the car out dramatically at low throttle depending on what kind of pump gas is available in your area. Without a FMIC he will probably not be able to run more than 16psi on mump gas because of heat soak of the factory IC.

 

[hostile]

Damn you guys know you #@%#@%#@%#@%.

Anyways he is running 16 on 93 octane pump gass plus octane booster.

We changed his iridium plugs out today and added ngk one head range cooler coppers. BRP7ES I think.

We also changed out his fuel filter. The day we installed his NX Ntercooler kit he ran out of gas. I rembered this and suggest both.

New pluges because the odler ones were wrong for turbo, plus running rich is hard on plugs.

The two things fixed his problem for now.

I ahve never tuned an AFC but we are going to hook it up some time this weekend. I also told him to fina an AF gauge.

His hesitation problems are somewhat fixed. Atleast when he is boosting it runs strong.

We will see what happend in the near future. Thanks a lot for the help.

 

[fast4wardTSi]

anytime

 

[dsmrocker]

i have the very similar Problem and i also have the iridium plugs in my engine but this was in a T-25 and stage one mods(buschur racing stageI). anyway, what i did is: clean the plugs and the spark plug well and RE GAP MY PLUG....THATS IT..... GOOD LUCK