1.8T cupra hesitation

[tzk]

Hello guys, here's one for you.
I`m new here i hope i`m posting well here.I have a Leon mk1 1.8t 20v cupra and i have this strange problem.
I stalled the engine once and ever since at around 3500-4000 rpm i have this hesitation, it`s not happening always but when it happens it`s sudden. After this, when i stop and drive away, it's really lumpy and the idle is really shaky. Another maybe unrelated issue, but it happens at the same time, is the dash light intensity changes, slightly, but you can notice the intensity following the engine RPM.
No errors, no codes no nothing on the dash.
Any ideas??
Best regards.

 

[tzk]

Hello guys,i still have the problem but still no answer who is in tommorow for a vag com scan?in slough area...thanks

 

[andycupra]

my first impression was a potential maf issue. Maf is the mass air flow sensor which sits in the intake, immediately after the airfilter/box. This measures the air flow which is used to measure the qty of air entering the intake and is used to determine fuel/air mixture. Therefore if this is not supplying very good information then this can clearly effect things. lumpy idle also.
One thing you can do, is unplug this sensor. this will put a light on the dash, and the traction control will not work, however the car will run using other data/some assumed info. If the hesitation and poor idling is not longer an issue this 'may' indicate a maf issue.
You can drive like this, but i would not advise ragging the car or doing this for an extended period of time, just long enough to diagnose. It is likely to run a tiny bit rich as it was run in a slightly safer mode. some say it wont be quite as quick, some say they see no difference.
If it is these, you can get these on exchange, it is VERY important you get the correct one so make sure you get the correct part number etc. a seat dealer visit is a good idea, but just to check what part number you want, they can be got cheaper as GSF / euro car parts etc.

Alternatively coil packs, which are bits that plug onto the put onto the spark plugs are a known to fail now and then, however i dont think this is the case here, if the car runs like a tractor and you usually get a light on the dash then thats usually a coil pack failed.
although you could check they are all fully pushed down and none have risen in place.

In your case, the bit thats different is that the dash light varies with the revs? - then could this be battery/alternator..

 

[tzk]

Thanks andy for all the details,saturday i`m gonna check/change the spark plugs if is necessary.the thing is i just refill with shell petrol and since then the problem start i scan it with a vag console and it says camshaft sensor but i don`t trust that console is a cheap one and a problem like camshaft sensor will put my engine light on and give me trouble when i start the engine.but my dashboard is clear like water.i`m confused i`ll try to take it step by step if nothing work...probably you know a good mecehanic or service.cheers

 

[mty12345]

Camshaft problem sounds perfectly possible to me. That would give you a flat spot at a certain rpm if the cam timing is wrong

 

[tzk]

mty12345 the thing is i just scan the car and it says camshaft sensor open or short to plus,but i refuse to trust the scan because the vag console is a cheap one 9£ and i had this problem with a golf 4 2.0 and the symptoms was totally different refuse to start the engine no power but now..i`m worried...any recommendation? good mechanic/service.....something?cheers

 

[andycupra]

when the car is not having the issue it runs well?

 

[tzk]

Yes it drives perfect power acceleration no turbo lag no nothing.but it's something strange and i'be just seen my engine light doesn't come up when I turn the ignition ON.i'm looking for someone who knows what is a cupra to give me a hand fix it..what you recommend?

 

[mty12345]

Yes it drives perfect power acceleration no turbo lag no nothing.but it's something strange and i'be just seen my engine light doesn't come up when I turn the ignition ON.i'm looking for someone who knows what is a cupra to give me a hand fix it..what you recommend?

Hi again mate.
The check engine light should always come on when you turn the ignition on. They are all leds and not bulbs, so they don't blow either. If yours isn't lighting up then 99.999% that someone has opened up the dash binacle and used a piece of paper or tape to cover the engine light over! That's why you probably have a camshaft code with no engine light on....... it's covered up.

I know what you're saying about it being a cheap reader but i don't think it would just invent a camshaft code that didn't actually exsist on your ecu. If you have a intermittent problem with the wiring to the sensor or the sensor itself, then that could more than likely be the cause of the symptoms you described, and that would be the first place i would start after uncovering your engine light.

 

[tzk]

Thanks matte that's fair enough.I'll try to find someone who can help me with this,if you know a good mechanic or garage let me know.all the best matte cheers

 

[mty12345]

Thanks matte that's fair enough.I'll try to find someone who can help me with this,if you know a good mechanic or garage let me know.all the best matte cheers

What part of the uk are you in?

 

[tzk]

Slough,Berkshire....

 

[mty12345]

Slough,Berkshire....

Can't help you on that mate, but if you start a new post in the mk1 section asking for recommendations, then i'm sure someone who lives near you will know somewhere.

 

[tzk]

It's ok matte I replace by myself the camshaft sensor there's no error now on the vcds but the car it drives horrible now i'my gonna replace the spark plugs in few minutes it drives like in 2 3 pistons no power no nothing

 

[tzk]

OK guys so 1 new camshaft sensor Bosch 4 new spark plugs NGK everything it''s perfect until the engine become warm/hot near 90 degree and one of the spark plug was wet but just a bit,my question is if is the coil pack fault...why is running perfect until is become hot?

 

[dukemaster17]

Does your car misfire ? Do you have access to a diagnostic to see if and what error the car sees ?
And another question did you wash your engine recently ?

 

[tzk]

Hi matte yesterday i was at mr clutch and he said my turbo is not working properly there's no fault codes on the engine sometimes and sudenly i lose the power and the car start to sound like an 3pistons engine.i need a guy who really know what to do with the vag com to check the injectors value and what is wrong with my turbo geometry or something... i still belive my turbo is fine

 

[tzk]

And i never wash the engine

 

[dukemaster17]

If you have a diagnostic you can log your car and see everything you could possibly have in your mind and solve all your suspicions.
I wish i was somewhere near there and help you but that's not possible.
The problem that you are describing sounds like faulty Coil Packs or Spark Plugs. You can also clean your injectors if you want to.
if you have a VAGCOM you can easily find the cylinder that misfires and get to the bottom of it. But if you don't then start the car and very VERY carefully pry out the power from Coil Pack on each cylinder and see if the problem returns (missfire i mean). BUT PLEASE BE VERY VERY CAREFULL OR YOU WILL GET ELECTROSHOCKED BY THAT HARNESS.
And could you please inform me about your turbo what do you mean ?

 

[tzk]

I had a engine fault camshaft sensor i replace that one i replace the spark plugs i've done that thing with coils ignition remove it one by one everything is fine engine is shaking when i try to unplug each coul and running well when plug it back......the thing is i don't have a vag com full just lite edution few options available and apart of thua i don't know how to go thru the chanels and check deep and like i said Mr Clutch told me my turbo is not working but that's it they don't explain me what is not working the funny thing is sometimes the car is perfect powerfull everything but sudenly it start to sound like a 3pistons engine and no power i'm struggle to drive it.my question is if is a Turbo why sometimes is perfect and sometimes not???it's a dilemma for me from a Turbo I'm expecting black or white I mean is working or not.but I have a middle way it's strange