Car Juddering HELP!

[JasePatters]

Hi, I'm new to this forum. I have recently bought a SEAT Ibiza 2.0 GTi (AGG). It was suffering from juddering under acceleration. With help from you guys (through searching posts), I have replaced the following with no cure......

Spark plugs
Coil pack
Fuel filter
Air filter
Cam belt
Crank sensor/engine speed sensor
Distributor cap
Rotor arm
ECU Temperature sensor
Lambda sensor

The HT leads look new so I haven't replaced those, but that's next on my list now. The crank sensor was totally knackered (cracked with wires showing), so I thought that was the problem. Also I replaced the cambelt, got the timing perfect (with help from Haynes manual and this forum), still no good. The strange thing is the car isn't too bad when cold/warm for the first say 10 mile, then it starts juddering badly after that, almost undriveable. Also when the car cold/warm it will accelerate fine if you change gear then give it a few seconds before you accelerate.

I'm pulling my hair out now. Thinking of taking it to a mechanics, but don't want to be beaten by this problem.

Can anyone help?

Sorry for the long post!

 

[Brummy]

Definately go for the HT leads, and whilst at it, clean the throttle body out

 

[truCido]

2nd on the throttle body!

 

[JasePatters]

Okay. Thanks. Will let you know the outcome.....

 

[orangemuffin]

haha, didnt see the other replys and as soon as i read the first post i thought TB..

Get a can of carb cleaner and get someone to rev while you spray the carb cleaner in...

bet you chuck some nice big puffs of black smoke out the back.

 

[suj]

+1 on TB or sparks/ht leads/dizzy cap/rotor arm, and even the air filter (or cleaning the airbox the filter is in)

 

[Fl@pper]

ECU Temperature sensor you say you changed - was it the right one ? as the symptoms suggest it's running fine when cold (rich) but judders once warmed up, poss still rich. I would plug in vag com and check the car is reading the correct temperature from the sensor

failing that it could be an air leak somewhere as when cold the overfuel is keeping it in a useable zone but when the overfuel (choke) drops off leaves it running lean with the leak

time to get some easy start out


whats it like ticking over ?

 

[JasePatters]

Thanks for the replies...

Fl@pper - The car idles fine, very slight blip (like 50 RPM) now and again, but nothing alarming. Took out old temperate sensor and made a note of the number on the underneath of it, and gave that to the chap on the parts desk. VAG COM plugged in and all I get is the common Hall Sensor fault. Water temperate reading is fine (as far as I can see). Although the Throttle position sensor reading on VAG COM (throttle angle) is all over the place when accelerating. Also sometimes if I accelerate off the car nearly dies.

I forgot to mention the CAT has a hairline crack in it and is blowing slightly. Would that cause a reduction in back pressure in the exhaust system? For some reason the previous owner has put the GTi 16V downpipe with CAT on, as I take it the GTi 8v the downpipe and CAT are seperate? Would this cause problems? Is it possible to take the TPS apart and clean it? I suppose it could be gummed up. The car car has only done 60,000 miles. The last onwer used it for work, which was only a few miles down the road I think. The car also looks like its been stood for a long time at some point in its life, and for the last 4 odd years has only cover 4,000 miles a year.

Sorry for all the questions, just want to get this problem sorted.

 

[suj]

clean out the throttle body then mate, sounds like the lack of movement might have caused gunk to build up (as they probably didn't use the throttle much)
get some from halfords, Wynn's Carb Cleaner, its like a 5er, and will last forever (so you can use for future cars)

 

[Rhys_Walters97]

I am also having the same problem but I have found it it's not the throttle body, coil packs, spark plugs, leads. So I am stuck for ideas, I have a 2002 Seat Ibiza 1.2 and it jumps revs in 1st gear but then will not do this in any other gear

any ideas?

Thanks!!