Fixed, but now hesitation :(

[mikemk4gti]

After breaking my ecu last week by messing with the earths I've now had a replacement and it's running again, I actually think its a fair bit quicker now too 
 I've fitted a few new earths just to be sure it doesn't happen again.
 Today was the first time I've actually driven the car for more than ten minutes, a lot of it in traffic, and I've noticed that there's a hesitation when the throttle is first pressed which wasn't there before. Also it's very jerky when you come off the throttle. I've swapped the blue temp sensor for another (used but tested resistance) and its no better.
 It idles fine at 900 Rpm and I've checked the timing and it's spot on. Anyone know what could be causing this?

[tomp]

Ignition amplifier, if you have another one try it.... Also known as a TCI unit, its next to the ECU...

[mikemk4gti]

Yeah got my old one, does it need to be screwed onto the ecu bracket to test it?

[Mr Blue]

They call this Digilag.  The ignition moduel ontop of the ECU does not have to be screwed down but if that was faulty the engine would not run.

Timing issue I think. Need's to be set like Rubjonnys guide.

http://www.golfgtiforum.co.uk/index.php?topic=33253.0


 

[mikemk4gti]

I've set the timing using that guide already, (excellent guide btw) the thing is it was running perfectly before?

[tomp]

They call this Digilag.  The ignition moduel ontop of the ECU does not have to be screwed down but if that was faulty the engine would not run.

Timing issue I think. Need's to be set like Rubjonnys guide.

http://www.golfgtiforum.co.uk/index.php?topic=33253.0


 

The 8v that I had to change the ECU on after it filled the bores with petrol was hesitating, I changed the ignition module and it cured it, it did start and run ok but was lumpy.. According to rubjonny the ignition modules are all the same

[mikemk4gti]

I've just been out and swapped the ign module over and it's still the same. I've noticed that its fine when cold and only start to do it when it's started to warm up.
 Also I've found out that it happens as soon as the cam on the throttle comes off the idle position switch.

[Roverdose]

my mate had this, timing. i know it sounds imposible from what you have said but i'll put a bet on it

[Mr Blue]

Coolant temp sensor change then time again.

my mate had this, timing. i know it sounds imposible from what you have said but i'll put a bet on it

Exactly that. Even if you set the timing like the guide it can still cause problems. You have to be dead accurate.

I've found mine gives better mpg and performance when its all set to 0 which is wierd.

[mikemk4gti]

I've checked it with a timing gun following rj's guide and it's ok. Just the co I've not had chance to check.