Jerking before turbo kicks in

[SexySeat]

Hi everyone, new to this site, and being a woman i know nothing about car mechanics, to try and cut a very long story short, I've had my 1.8 20v Turbo for over a year now, and its fair to say its had it's fair share of issues in that time, i have no idea if any of its past problems are relevant but to be sure I'm gonna run through them anyway.

Firstly i started having problems with the clutch, it started sticking to the floor. After numerous attempts at working out the problem I had the master cylinder changed, eventually i just decided to go ahead and have the clutched changed, whilst doing this the garage found some serious engine problems, where one of the past owners had had a bodge job done to it, something to do with the crank shaft. Found a new engine, had it changed only taking certain bits off the old one, one thing being the turbo. Got the car back and so far no problems with the clutch and although i couldn't really feel much of a difference with the engine I'm sure its a lot healthier. My issue is this jerking feeling just under 2000rpm, it almost feels like the acceleration pulls back for a second before kicking in again, this problem has been here from the start, before all the original problems, I keep thinking every time work is done to the car that it will sort the problem, it never does..

Again had the car back at the garage the other day due to the engine management light coming on, it had its lamber sensors changed and another sensor (all to do with the exhaust i believe), wow yes i felt a difference when i picked the car up, but that god dam problem is still there, and actually feels slightly worse. This problem has stayed through a clutch change, engine change, and various other changes, as far as we can tell the turbo looks fine, as this was my first thought due to it still being off the original engine.

Anyone got any ideas? I just want this car driving smoothly, regardless of everything i still love the car, she's like my second baby (as sad as that sounds) It's so frustrating any help would be much appreciated. Thanks in advance xxx

 

[nd-photo.nl]

-Disconnect the MAF (mass airflow sensor) and check if that improves
-Check the crankcase ventilation hoses for split pipes

Also if you have a laptop with WinXP or so, buy a Vagcom cable via eBay, so you can check errors (and clear errors) yourself without paying the garage.

 

[traumapat]

does the car start easierly? do you get this issue on a cold and hot engine? Does it idle ok?
does the car have any modifications? DV ok?

Cars eh?

 

[neil_1821]

Agree about buying vagcom, my engine management lights been on a few times with a faulty reading off the glowplugs and I've reset it and solved the problem

Secondly, I'm not sure how severe the jerking feels, I've had similar problems when putting my foot to the floor, but my leons mapped, on mine it seems like the engine management is trying to control the power too much, you hear the turbo spool up, it starts to go and then it's like slamming on your breaks for a second and then it'll spool up again and off you go.

Maybe try turning the traction control off, see if it still does it?

 

[RaviR50]

-Disconnect the MAF (mass airflow sensor) and check if that improves
-Check the crankcase ventilation hoses for split pipes

Also if you have a laptop with WinXP or so, buy a Vagcom cable via eBay, so you can check errors (and clear errors) yourself without paying the garage.

do youhave to get a programe then with it? i want to reset my EGR but i dont have the cable atm just need to know if i will need another programme. also where do i plug it in??

 

[RaviR50]

ooh talking about the actual subject lol I had a similar thing on my old clio (have it on my tdi leon too) but i changed the coilpack on the clio to get rid of it and another thing you could try is changing the fuel filter

 

[CupraRmark]

Try a throttle body reset and clean

 

[RaviR50]

try a throttle body reset and clean

+1.

 

[SexySeat]

Thanks for all the replies guys, none of it actually makes much sense to me, i think i need to marry a mechanic lol.

In reply to some of your questions. The car starts first time every time without problems, its idles fine, the issue is worse when the engine is hot but is still there on a cold. Except the exhaust the car has no other mods that I'm aware of.

In regards to the management light, its the second time it has come on since i got the car, the first time being for a solnoid valve and last time being the lambers and air bi pass valve, i do believe the sensors were correct this time as the car also failed its mot on emissions, obviously due to the lamber fault.

You don't need to put your foot to the floor for it to jerk you can just lightly press the accelerator and it will do it, only mainly in 1st and 2nd, i don't tend to give it much gas until over the 2000rpm mark, where you know it will behave normally. It so almost feels like the car is pulled back for a couple of seconds before being let go again.

Think I'm gonna have to go back to Seat, although when i explained what the car was going to them last time, they told me it would have been as a result of the air bi pass valve. Now that that's been fixed the car feels worse. I'll get to the bottom of it eventually..

 

[dandanibiza]

Sounds like I'm having the same problems as you. It baffled me for ages trying to work out what it could be. Thought it was n75 valve, the dv, boost/vac leak, maf sensor etc etc.

In the end I managed to borrow a vagcom to see what codes I had and it came up with maf sensor faulty and coolant temp sensor. I then booked it in to a garage and they diagnosed a faulty diverter valve although this didnt come up on the vagcom. Changed the coolant sensor and swapped the standard dv to a forge 007 and that made a big improvement, although still had the hesistation/jerkiness.

So I took my car to a more reputable garage after feeling the previous placed ripped me off (which they did). Had it back today after a 3 hour inspection of boost leaks, fuel pressure tests and further diagnositcs and it turns out my fuel pump and filter needs changing as my fuel pressure was only half of what it should have been causing the random boost and detonation.

 

[SexySeat]

Oh dear i knew this problem wasn't going to be easy to diagnose. The good thing for me is the garage that i use, i know really well, so i can trust them, its just i feel the problem will have to be found before they can fix it, as so far they haven't been able to find the problem. It doesn't help that everytime they look for the issue something else comes up and we all start believing that'll be the problem sorted, this is the first time the problem has been worse after having something fixed..

I really wanted to avoid getting Seat involved in this but now it feels as if i need them to find the problem. Is this vagcom thing easy to use? Sorry to sound stupid, but i really have never had a car baffle me like this one has..

A woman once said to me, theres two thing you'll have a problem with in your life and that's men and your car.. My god was she so right haha

 

[Teasy]

Try a throttle body reset and clean

I got this done......what an amazing difference

 

[Teasy]

Oh dear i knew this problem wasn't going to be easy to diagnose. The good thing for me is the garage that i use, i know really well, so i can trust them, its just i feel the problem will have to be found before they can fix it, as so far they haven't been able to find the problem. It doesn't help that everytime they look for the issue something else comes up and we all start believing that'll be the problem sorted, this is the first time the problem has been worse after having something fixed..

I really wanted to avoid getting Seat involved in this but now it feels as if i need them to find the problem. Is this vagcom thing easy to use? Sorry to sound stupid, but i really have never had a car baffle me like this one has..

A woman once said to me, theres two thing you'll have a problem with in your life and that's men and your car.. My god was she so right haha

Some men

 

[SexySeat]

I just had a thought on the mention of the fuel pump and filter..

A couple of weeks ago just after having the lambers changed, the fuel light was on and the car jerked quite badly jolting the fuel light off immediately. It then didn't come back on until the following day. With my experience with this car once the light is on it normally stays on, so straight off my thought was the problem had caused the light to suddenly turn off.. So would that have something to do with fuel pressure? It all of a sudden feels like i may be getting somewhere..

Being a big help, thanks guys xx

 

[SexySeat]

Sounds like I'm having the same problems as you. It baffled me for ages trying to work out what it could be. Thought it was n75 valve, the dv, boost/vac leak, maf sensor etc etc.

In the end I managed to borrow a vagcom to see what codes I had and it came up with maf sensor faulty and coolant temp sensor. I then booked it in to a garage and they diagnosed a faulty diverter valve although this didnt come up on the vagcom. Changed the coolant sensor and swapped the standard dv to a forge 007 and that made a big improvement, although still had the hesistation/jerkiness.

So I took my car to a more reputable garage after feeling the previous placed ripped me off (which they did). Had it back today after a 3 hour inspection of boost leaks, fuel pressure tests and further diagnositcs and it turns out my fuel pump and filter needs changing as my fuel pressure was only half of what it should have been causing the random boost and detonation.

Just having a look on fuel pump problems, apparently i good way of knowing if your fuel pump is on its way out, is if you have problem with the car starting up and stalling. Did you also have these issues with yours? as i definately can't fault my car on how it starts and it's never stalled once.

 

[repsolbladedaz]

Sounds like the MAF sensor to me. Like previously stated, unplug it and see if it makes any difference. If it does then its the MAF (mass air flow meter).

The black box on the air intake pipe......unplug it and test.

 

[mjstokes85]

Did you ever get to the bottom of the jerking around 2krpm? I am having the exact same issue with my Ibiza Cupra TDi. I was thinking a MAF issue, I am having it fault scanned tomorrow so hopefully that will show the issue.

 

[Lukai]

It sounds like a similar problem to what I am having in my 1.8 20VT, although mine seems to dip in power around 3krpm. It sounds and acts like when the ESP steps in.

 

[Michal James]

Mate,

I read all members discussion but the best option for you is to hire some professional or mechanic to solve this issue.

 

[Exe_LeonCR]

Mate,

I read all members discussion but the best option for you is to hire some professional or mechanic to solve this issue.

True but if the area the problem is in is known it will save a lot of time and money. Sounds like a type of fuel cut/pressure problem to me.

Out of interest has the maf been the same one on both engines?

Anyone around your area got Vagcom? Put out a thread in the Vagcom section.