Petros 0 Posted May 24, 2016 Hi folks, got a strange problem with a 1.8 20v turbo. Full disclosure, it isn't in my Corridor, it's in a mk1 Leon. I'm posting here cos it's generally a helpful place and I know a bunch of you have done 20v conversions and hence know their electrics rather well. Plus I've still got my VR so I figure it's allowed :-) Long story short - engine cranks over fine but never starts. No spark and fuel pump isn't running so it's as if the ecu doesn't realise it's being asked to start. Using vag com to read the measuring blocks shows no engine speed signal (G28) while cranking. Changed crank sensor and replaced ECU. Still no signal. Anyone know how to test the wiring from ecu to crank sensor? Or have any suggestions of other tests to try? Sent from my Nexus 6 using Tapatalk Quote Share this post Link to post Share on other sites
Petros 0 Posted May 24, 2016 Corridor lol. That'd be Corrado auto corrected! Sent from my Nexus 6 using Tapatalk Quote Share this post Link to post Share on other sites
Bengould 10 Posted May 25, 2016 My scirocco did the exact same thing when I put my 20v engine in. Check your ecu is still getting power when you're turning the engine over. The fusebox pin I had used to power my ecu was turning off when the starter was engaged. Moved it over to a different one and it worked first turn of the key. Ben. Quote Share this post Link to post Share on other sites
Petros 0 Posted May 25, 2016 Thanks Ben. I'd considered that having read similar issues from a few people transplanting a 20v into a mk1 or mk2. I had discounted it because: 1. The entire loom, including all relays, fuses, sensors, etc. is standard factory fit and hasn't been removed (it's not a conversion, just a modified car with a fault), 2. Vagcom seems to hold its connection during cranking. I'd expect a comms error if the ecu was losing power. I'm far from certain on that last point though, as I've never seen an ecu cutting out to know exactly what symptoms to expect. Any simple conclusive checks I could do? Sent from my Nexus 6 using Tapatalk Quote Share this post Link to post Share on other sites
Bengould 10 Posted May 25, 2016 I never got a comms error in vagcom, just wouldn't start. Can't remember which pin it is but put a multimeter on the ecu switched live and an earth as you crank it, if it goes off that's your problem. If not that's about as much help as I can offer. Rubjohnny on club gti would be the man to ask though. He is a bit of a wiring loom legend. Ben. Quote Share this post Link to post Share on other sites
Petros 0 Posted May 25, 2016 Cheers, I'll give that a try, and hunt down johnny if it's ok! Sent from my Nexus 6 using Tapatalk Quote Share this post Link to post Share on other sites
Petros 0 Posted June 7, 2016 Got this solved finally - it was a loose ground connection from the ecu. Well hidden so took a good while to find. Thanks for the help and suggestions! Now I can return to getting my VR back on the road :-) Sent from my Nexus 6 using Tapatalk Quote Share this post Link to post Share on other sites
