Hi

maybe someone has an idea how i can fix this problem.

When the engine has warmed up and I want to accelerate, the engine drops into lean mixture and there is no power. After about a sec the engine riches the mixture up again and starts accelerate but sometimes also with misfires.
When pushing the gas pedal really, really slow the engine runs smooth mostly.
Also load changes often end in jerking


Mods that may effect:
-VMIC
-Rtek 1.5
-Air Valve removed
-BOV
+spark plugs may be a bit old

things I´ve already checked:
TPS, idle mixture, AFM, ECU for errors, intake temp.sensor, water temp.switch,
intake system for holes, ignition timing

I can´t remember what I may have done when it occured a few weeks ago.

-Patrick

 

Really. What year car???????? Must be a series four with a RTEK.

Does the car have the solenoid resistor package????

Have you installed different injectors than stock and what are they? High or low impedence/resistance????

 

if the plugs are old, might wanna replace them. your hesitation problems could be from the injectors? maybe, i'm not sure... how are your ground points? you might wanna check those too since it rusts up due to age of the car.

 

Yes it´s a S4 ´87

@HAILERS:
I know the solenoid valves but where is the solenoid resistor package ?
stock injectors

@dothacker:
What do you mean with ground points ?



sorry for not unterstanding everything, translating word by word doesn´t make sense to me

maybe I´ll try reseting the ECU

-Patrick

 

i have a problem that is sort of similar my car is fine accelerating till 5000 rpm then bogs down but if i let off the gas runs smooth

 

our cars have ground points (a piece of wire bolted on to the chassis). like the ground wire on the radio (black wire), or your negative wire that hooks up to your battery, those are ground wires. i dont have the ground points memorized on the top of my head, so i will suggest that you search for them here in the 2nd gen page.

another idea is... have you checked your O2 sensor?

 

Ah ok now I understand.

Also thought about the O2 sensor.
It gives out a signal when the engine is warmed up,
but it seems like the hesitations start when the O2 sensor starts operating.
So maybe its not ok.

Oh I remember I have the prob that the stock boost gauge reads too little boost,
compared to my aftermarket one.
I have an other boost sensor but it gave the same voltage at atmospheric pressure,
and the stock gauge didnt read 0 with engine stoped and ignition on.

-Patrick

 

See if the ECU spits out any erros.
Or probe the ECU with a multi meter and check values from the FSM.

 

sounds like a faulty TPS sensor to me.

 

replace plugs first.
clean grounds

double check TPS. try testing the resistance with an analog multimeter (as opposed to a digital one)... you might be able to see problems with the resistance sweep better