106 GTi running issue

11th March 2016, 15:42

Took my throttle body off the other day to clean the ICV as when driving under 2k the car will randomly violently jerk/kangaroo, the only way to stop it is to dip the clutch or accelerate out of it, I've changed the front and rear wishbone bushes as they was shagged thinking it could be that however the problem is still there (anyone got any ideas)

Anyway, the other problem is this... I took the throttle body off and cleaned all the sensors and the body as was quite gunked up, now when i accelerate hard (like quickly put throttle to the floor) it misfires and splutters for a second and then goes, if I accerlate slowly it's fine, but it's only since I've cleaned the TB/sensors, any ideas?

11th March 2016, 18:39

sounds like tps is buggered/contaminated with cleaner.

12th March 2016, 11:32

Strange as the tps is the only one I didn't take off, the issue I'm originally trying to rectify is the kangerooing under 2k rpm, it does it nearly all the time, all you need to do is drive under 2k mainly in 1st and it will drive fine then all of a sudden it jerks like your bouncing off and on the throttle, it's strange as when I changed the wishbone bushes it was okay for a while now its doing it again, but it's annoying now it's misfiring as going on the throttle quickly as round track it's going to drive me mad

12th March 2016, 13:58

If you've cleaned the throttle body, cleaner can find its way up the spindle bore into the TPS.

12th March 2016, 16:28

Didn't use any cleaner just a clean rag and wiped all the gunk off til it was gunk free

13th March 2016, 22:18

Unplug the TPS and see how it drives then. Expect a fast idle but see if the kangerooing has gone.

14th March 2016, 19:01

Okay mate I will do thank you very much

15th March 2016, 17:24

I unplugged the TPS and it didn't seem to jerk at all, the idle stayed above 2k as its when your under 2k it generally happens but didn't jerk, but it's still misfiring even with the TPS unplugged, it's when you accerlate hard/quickly it sounds like a semi auto gun before accelerating normally but today it's been taking longer to clear out and letting off a poof backfire that sends like a thud that can be felt through the car, once the RPM picks up its all okay all the way to redline pulls strong and doesn't miss it a beat but when the revs are low and accelerate hard it really splutters?

15th March 2016, 21:05

Sounds to me like you have two issues.
Missing under load is maybe a bad plug or coil.
Jerky running is caused by unmetered air making the engine run fast. If the ECU sees a closed throttle and high revs it shuts the injectors off, thinking you're on the overrun. (which is why I said unplug the TPS so it doesn't know throttle position so won't turn them off thus stopping the Jerking)
Unmetered air is passing into the intake, either via a leak or via the ICV. ICVs do fail but also the H-Bridge in the ECU to drive the stepper motor in the ICV are also occasionally known to fail. If you take your intake pipe off the throttle body and run the engine stick your finger over the crescent-shaped slot at the end of it, that's where the ICV get its air from. If it causes the engine to stop you have either an ICV or ECU problem, wiring loom excepted of course but they less frequently give trouble.

15th March 2016, 21:16

Okay thanks will try that tomorrow, the misfire issue has only happened since I cleaned the throttle body, was fine before I took it off and started missing once I fitted it back on. So must be something around that area. As the TPS stopped the kangerooing would you say replace that?

15th March 2016, 22:15

Quote:

Originally Posted by Chipwizards

Sounds to me like you have two issues.
Missing under load is maybe a bad plug or coil.
Jerky running is caused by unmetered air making the engine run fast. If the ECU sees a closed throttle and high revs it shuts the injectors off, thinking you're on the overrun. (which is why I said unplug the TPS so it doesn't know throttle position so won't turn them off thus stopping the Jerking)
Unmetered air is passing into the intake, either via a leak or via the ICV. ICVs do fail but also the H-Bridge in the ECU to drive the stepper motor in the ICV are also occasionally known to fail. If you take your intake pipe off the throttle body and run the engine stick your finger over the crescent-shaped slot at the end of it, that's where the ICV get its air from. If it causes the engine to stop you have either an ICV or ECU problem, wiring loom excepted of course but they less frequently give trouble.

Massive thanks for this, it'll certainly help me tomorrow trying to sort the exact same issue

Sendt fra min SM-G920F med Tapatalk

16th March 2016, 18:25

Quote:

Originally Posted by Chipwizards

Sounds to me like you have two issues.
Missing under load is maybe a bad plug or coil.
Jerky running is caused by unmetered air making the engine run fast. If the ECU sees a closed throttle and high revs it shuts the injectors off, thinking you're on the overrun. (which is why I said unplug the TPS so it doesn't know throttle position so won't turn them off thus stopping the Jerking)
Unmetered air is passing into the intake, either via a leak or via the ICV. ICVs do fail but also the H-Bridge in the ECU to drive the stepper motor in the ICV are also occasionally known to fail. If you take your intake pipe off the throttle body and run the engine stick your finger over the crescent-shaped slot at the end of it, that's where the ICV get its air from. If it causes the engine to stop you have either an ICV or ECU problem, wiring loom excepted of course but they less frequently give trouble.

Hi,

Just drove the car home from work and took the intake off and put my hand over the half moon type thing on the throttle body, the car hunted and went to die, took my hand off and all was okay again, repeated procedure and same again went to die. Odd as the idle isn't irratic, sometimes drops low or idles lumpy like a unmapped high lift cam idle but doesn't 'bounce' like I've seen some do. So does this mean ICV is buggered and causing the kangaroo?

16th March 2016, 23:43

Unplugging the TPS just allows me to get a better idea what's wrong.

If you are able to drive it keeping the revs below about 1600-1800 does it still kangaroo or does it just do it at revs above this level?

Cleaning the throttle body won't cause a miss under load, something else is wrong or something has been disturbed.

17th March 2016, 06:03

No it kangaroos tound that rpm range below 2k basically sometimes it's okay but 7/10 times it will kangeroo it's like I've lifted my foot off the throttle and back on again when I haven't

19th March 2016, 12:45

Bump any ideas? Just seems weird that when you accerlate gradually it's fine, it's just when accelerating quickly, but it doesn't do it any other time only from low revs doesn't misfire at any othe time in the higher rpms? Icv related buggering the mixture up at low rpm maybe?

29th March 2016, 18:23

Bump.

Problem is getting worse, the misfire now occasionally happens all the way through the Rev range trying to get hold of a coil pack see if that resolves it. Plugged it into snap on machine brought up O2 sensor Circuit (maybe because of decat?) or could that be a faulty lambda causing the issue??

29th March 2016, 23:14

Unplug the MAP sensor and see if the thing drives reasonably well or not (a bit dodgy idling excepted).
If it's acceptable then the TPS is probably OK but if not it's probably buggered.

11th April 2016, 17:41

Update: Problem still persists! Poxy car, I changed the Spark plugs and gave the coilpack a good clean as well as the crank sensor, after that it's running on 3 cylinders 90% of the time, someone who is in the know with these cars said to try changing the injectors, I changed them tonight to a fresh set I had sitting about in the garage and the issue is still the same, any sort of acceleration now is making it misfire, however if I keep my foot on one place the 4th cylinder kicks into life then sometimes I can accelerate without a misfire for a few seconds then it misfires again.. Today on the way home from work it did feel a lot better (before changing injectors) but was still misfiring the issue hasn't just vanished, got a track day in 2 weeks time, time is running out!

11th April 2016, 21:29

You say you gave the coil pack a good clean but have you changed the coil pack at all? Mine is running on 3 cylinders and I know for sure its the coil pack but as I have started striping the car for rust repairs it's not that important just now.

11th April 2016, 21:47

Update2: just fitted new crank sensor; still no luck here's what I've done so far

new crank sensor
New injectors
Cleaned inlet
Cleaned map sensor
Cleaned throttle bodie
Cleaned sensors
New spark plugs
Plugged into snap on machine only fault was 02 sensor cause decat

Chasing tail

11th April 2016, 21:47

I haven't changed the coil pack get trying to get my hands on one, that's probably what it is but trying other things that I have lying around the house

11th April 2016, 22:36

That would be the next thing on my list mate.

10th May 2016, 10:13

Coulpack was the issue, after changing everything else it was the coilpack all along. Thanks to all that helped