*Help please* - Rev-ing between gear changes/no power to vag-com cable???

[Cupra_J_RS]

Hi all,

The engine management light come on on my car not long after i bought it, first thought was to check coil packs, one of which had 'popped' up, so i pushed it back down and the car has drove fine ever since. The management light is constantly displayed but i was quite sure i had solved the reason to why it come on.

However, last weekend, my dad (who works for the AA) had some free time so we plugged the diagnostic machine in just to have a look at the error codes and to clear the engine management light, but the machine was picking up no power through the port below the steering wheel - by the fuses.

My dad was totally surprised and said he's never known this to happen. Baring in mind my dad uses the machine daily, and so was completly bewildered. Any ideas why it picks up no power? We had the ignition on, i tried messing the the cable for a faulty/looconnection but still no power.

Also, i had my car lowered last week by a mate with an Ibiza Cupra R, we took the car for a test drive, and he drove as he wanted to have a feel for how quick my car is compared to his. He instantly said the car holds its revs inbetween gear changes. I had thought this on several occasions, when accelerating hard and wanting to change gear quick, the car does hold the revs inbetween gear changes, but i put it down to my 'poor' driving skills.

My mate is quite sure the engine management light is something to do with the car revving between gears, any ideas what this could be?

Like i sad, the car drives fine, and this 'revving inbetween gears' is only noticeably when driving the car hard i.e. accelerating hard and wanting quick gear changes.

I know i need the error code readings to get a better idea of the problems, but without the machine picking up power through the hand held diagnostic machine, what else can i try?

Absolutly any information/ideas are appreciated.

Thanks, James

 

[MIkey kc]

you first need to find out why it wont pick up the diagnostic machine! could be a blown fuse! but i have this prob before on the mk3 ibiza when trying to get the diagnostic machine to connect with teh car.... and i no you think this wont work and what the bloody hell im i talking about but if you unplug the radio it will connect... strange but it works, and i dont no y! then get the fault memory read and repair it.

 

[GlanzaV]

I had a similar problem with a generic "scantools" OBD2 reader not getting power from my OBD port -- took it to a local VAG specialist and his Über machine got power from it fine?

 

[Cupra_J_RS]

Thanks for both responses.

Mikey Kc - when you say unplug the radio, unplug it from where? Unplug the ISO block connectors which are plugged into the back of the radio head unit?
Why does it work when the radio is unplugged?

Which fuse should i be checking which supplies the OBD port?

I know if i took it to the dealers they would probably know the reasons to why it picks up no power, but my dads fault reader & laptop is the top spec'd machine, and so its def a problem with my OBD port rather than the equipment. Plus its free when using my dads equipment!!

Thanks again though!!

 

[m0rk]

James, quite often AA/RAC kit doesn't work on many cars - VAG group in particular - weird given the standardised OBDII stuff. but the port works fine (else it wouldn't have scanned all the while for me)

but... the prolonged revs indicated a post throttle body leak - so have a look over the inlet manifold & check the hoses (small ones) for leaks/cracks

 

[Cupra_J_RS]

Thankyou Mark, will have a look later today if the rain stops!!
I have new pics now of the car, with the coil overs fitted etc.

 

[techie]

In particular pay attention to the vacuum pipes under themanifold that al connect to the brake servo.

 

[Cupra_J_RS]

Ok stupid question time...baring in mind i know very little about what things do under the bonnet...what pipework am i looking at? I had a 10min look and feel this morning at every section of pipework under the bonnet that i could physically see/feel. But could not find no splits or disconnected pipework.

I need help!! I need the idiots guide of where to look/feel etc....

 

[m0rk]

look from the big silver thing at the front of the engine (inlet manifold) on the left side there are 'pipes' that run to the big black circular thing (brake servo) at the rear of the engine bay against the firewall

check these are all connected up tight, and check for cracks

 

[cupra_matt]

The reving between gear changes could quite possibly be the clutch pedal switch.

 

[Cupra_J_RS]

I have noticed a 'clicking' sound when pressing the clutch pedal down, nothing major, but i can hear the clutch kinda make a click noice when its fully pressed down...is this any relation to the reving between gear changes?

 

[cupra_matt]

Check the switch, mine did the same, found the switch on mine unplugged, but yours is probably faulty.

 

[Cupra_J_RS]

Where is the switch? Is it instantly noticeable to see if its unplugged/faulty?

Thanks though, shall be checking it as soon as i get chance!!