Slight 'hiccup' on acceleration

[ICEYPOLO]

Hi guys,

over the past few days i've developed what i can only call a 'hiccup' under acceleration... it happens at between 1700 - 1800 rpm in 2nd, 3rd 4th, 5th and nowhere else!? like a 'jerk' then its gone...

it still pulls and feels fine but cant explain why it would all of a sudden start this?

scott

[Josh_PoloGTi]

First off, get vag-com plugged in to see if there are any codes...

Then, in order, do the following:

Change your plugs (get OE Bosch ones from the dealer)

Clean your throttle body

Change your green Temperature Sender

Change your HT Leads (if they're still original)...

[mikegti]

I was gonna suggest checking that your not getting any arcing across the insulation on one of your plugs. I had that on an old car but it was an occaisonal 'jerk' not at just one point in the rev range.

Isn't 1700rpm a little slow to be booting it? (i thought it puts a bit of stress on the engine?) ...but then if it wasnt doing it before... ?

[ICEYPOLO]

its not necessarily under hard accelaration just whenever it goes through that point.

my work place has a 20mph speed limit so i'm regularly pootling round at say 1500rpm and i notice it everytime i pull away....

think i'll get my mates vag com and change some plugs etc. - cheers josh

scott

[Josh_PoloGTi]

I had a similar problem, but mine was at around 3k rpm...

I did all of the above, and the problem went away!

[ICEYPOLO]

seems to be getting progressively worse through the range, now going from say 1500 - 2500 rpm...

will def. do all above tomoz and hopefully should sort it!

cheers

[ttaw2]

And the survey says??

Working on what's gone wrong with mine in the past, this sounds like either HT or cambelt..

see http://www.tigerstyle.co.uk/poloforum/v ... hp?t=10681

Hope it's the HTs!

Edit - A good way to check your HTs aren't arcing is to pour water over them, you'll soon find out if they are or not! It's what the garage did to diagnose mine!

[vinau_uk]

yeah that happen to me too. only notice it today after driving for 4hrs in london. seems to me is happening when the car is warm. between 1500-4500 rpm. the car just stop the response how it will normally do. so what kind of HT leads r recommended ? and spark plugs? how much am i expected to pay?

[ICEYPOLO]

i cleaned the throttle body, changed the HT leads and this sorted the prob. thank god!

original VW leads were £11 each from the dealers - that was with discount tho so might be bit more!

scott

[Josh_PoloGTi]

Glad it's fixed.

Another satisfied customer!

[vinau_uk]

apart from VW ht leads, can i put any other performance lead on the GTI? like Magnecor kv85? and do anyone know which spark plugs is best? i was looking at some Splitfire put cant find the right ones.

[mkone]

I have had a similar sort of problem for a while now, the problem will go away for a while (week or two) then re-appear with an occassional hiccup/jerk, I've plugged in the VAG-COM and apparently my (g28) speed sender unit has had it. Being repaired tomorrow so will let you know if this solves the problem!

[morrismen]

If it is HT leads, then you should be able to see the arching if you take the air filter box cover off and watch the engine tick over in the dark - I mean in the garage - pitch black if possible. And, if the engine is damp, it will do this even more.

Senders tend to go wrong if sprayed with WD-40 or damp start. They do not like this stuff - it dissolves the carbon track (negative) that it uses to measure speed.

This sort of problem has normally been attributed to the cam belt tensioner in the past. Perhaps we need a re-think on what to check for first as Josh has listed, BEFORE changing cambelt tensioners.