Help Golf mk3 gti 8v way to lean?

[flusted 0]

My mrs mk3 8v gti has had a fault of "bucking" whilst under load and its driving her mad (and me).

Ive changed coil,dizzy,plugs,leads,rotor,lambda,afm, then went to get co checked and its .5?

It has a cat bypass and i believe its way too lean? how do i richin it up? theres no adjuster on airflow meter

 

Help as she wants to drive it to london next sat from the isle of wight and im not goin with her

[VEEDUBBED 0]

Could be loads of things,fuel press.good?,injectors partially clogged up?,FPR good?,rubber pipe ok?

misfiring under load,old,hard ign.leads?,hall sender playing up?(very common,especially on valvers).

Let me know if you suss it.

[Crasher 3]

What engine is this, 2E, ADY or AGG? The problem is likely to be the cat bypass itself. When the cat is removed, the lambda sensor starts to run too cool and gives an inaccurate signal due to the big glowing red hot monolith just behind it having been removed and this has always been a problem. Try putting the cat back on and see what happens. It is possible to fit a lambda sensor with a more powerful heater but these require a controller relay and upgraded wiring to the lambda sensor.

[flusted 0]

i believe its a 2e, new leads and i changed the dizzy with no joy.

[ben16v 0]

my mrs 2e has a hell of a stutter under throttle, changed lambda, temp sender, service etc, nothing changed it wonder if this is similar?

[flusted 0]

IVE TRIED WEAKENING THE SPRING ON THE TOP OF AFM oops capslock, and its better but not right

[Crasher 3]

Whatever you do to increase or decrease fuelling by altering the air flow meter, the ECU will alter it back to where it thinks it should be, based the voltage from the lambda sensor. From the fact it has an air flow meter rather than an air mass meter, it is a 2E and unfortunately the diagnostics are pretty poor on these, especially early ones and they often won't communicate with VAG-COM. A common fault on the 2E that gives the symptoms you are suffering is failure of the throttle potentiometer on the back of the throttle body but before replacing this you should have this confirmed with a fault code read if possible. On some later software versions of the 2E ECU, there was limited live data output where the operation of the throttle pot could be observed.

[flusted 0]

I have a spare throttlebody, should i give it a try?

[flusted 0]

update, seems i may of been a big plonker.

When i changed the elads about 6months ago, i changed them for known good 1s (so i thought), but ive just fitted new 1s and the stutter has gone away 8)

note to self, always buy new ignition parts :lol: