I bought an 03 1.9jtd multipla a few months back that had a few issues. It wasn't running when I picked it up. Would crank but not fire.

The dude I got it from reckons as it gets warmer out side it will start. I though bs but yeah still took the punt and bought it. I scanned it a couple times. Comes back saying egr and immobiliser problem recognising the key p1800. Had the key scanned at a lock place. They said can read the transponder and it has a code saved. Anyway yesterday I thought stuff it I'll try again just to see. The key light flashed on the dash for the first time like it's meant to and fired up. Turned it on off quite a few times and everything was good. Took it out for a blast and certainly feels like a blocked egr and has a crank pulley issue to. Noisy when idling low, Got home after work tonight. It started no dramas. So thought I'd do the crank pulley. Put another one on and again it's back to not seeing the key. Hmmmm. Annoying.

Is there anything temp related in the immobiliser circuit that could cause anything like that. Just seems way bizarre to. Is the anyway to check the key aerial? Is it just the key aerial and ecu that's the immobiliser or is there another box somewhere I'm missing. Any ideas would be greatly appreciated.