Could It Be The Ecu?

[humanz 3]

Firstly, i've had some idling issues from the go on my 1.9 GTI. I'm still trying to cure these. To this end, I recently got a 1.9 afm to match my 1.9 ECU for my 1.9 engine, after running the engine on a 1.6 AFM and ECU. But the 1.9 ECU has always behaved a bit strangely, which is why I was using a 1.6 ECU in the first place: once the car is idling in neutral, I can rev all the way to 6500 rpm without a miss. No problems at all. But once I'm really giving it the beans on the road, the car acts as if it has a fuel cut right around 5500 rpm. Something just stops doing what it's supposed to. Once the revs drop back down to below 5500, the car has some go again.

 

I don't know what to make of it. Additionally, my ECU has this wire that comes out of it which is joined with a second wire leading back into the ECU. Any ideas what those wires could be for? Is it a known mod or something?

 

I'm not using a tachy relay. The car only does this with the 1.9 ECU. The 1.6 ECU does not exhibit this, and will rev as far as I let it without a problem. I've recently changed the ignition amp, plug leads, coil, and swapped in a spare fuel pump I had lying about. I plan to purchase a new coil and uprated fuel pump in a few weeks.

 

So is it just a bad ECU, or is it that the ECU isn't working well with some other component in the car?

[welshpug 1,666]

have you tried a different distributor? or just the cap and rotor arm?

[humanz 3]

Yes. Different distributor.