Mk3 Golf Electrical Fault. HELP PLEASE. Won’t Start

[Mk3GTISpencer]

Good afternoon everyone.

New on this forum but I can see me being a regular very soon.

Anyway back to the point in question.

I’ve recently purchase a 97’ mk3 8v Golf that’s been off the road for 10years. I believe it’s original fault back then was the fuel pump but was never replaced and didn’t turn a wheel after that.

I’ve changed the fuel pump which is now buzzing away as it should but the car still just spins over.

I’ve checked for a spark and we seem to be missing that also. I’ve check the 3 wires to the coil pack and we have the earth and ignition live but no live when cracking.

Am I correct in thinking that the cranking live comes from the ECU? (Could this be at fault)

Any help on getting this started would be greatly appreciated

If anyone has wiring diagrams for this year also that would be great as I found one from 95’ but the wire colour doesn’t seem to match.

Thank you all in advance

James 👍

[Pete le Deet]

Hello, James,

As I understand it, the engine ecu responds to the distributor Hall sensor and crank sensor, and operates the h.t. coil. The crank sensor is a common failure, without it the ecu doesn't seem to regard the engine as rotating. I thought it doesn't inject fuel in this situation, but I'm not sure if it won't spark either. 

There's a method I've used for checking the crank sensor, though. Are you aware of what's sometimes called the digital tachometer, part of a hidden section of the instrument cluster? See a topic here, tailed atm by my earliest post, titled 'hacking the Mfa'

[Mk3GTISpencer]

Hi.

Thanks for you response. I’ll have a look at the. I believe the guy that had it recently put a new crank sensor in it. But I’ve also been told there’s different types.

Think I need to start from scratch.