To try and cut a long story sort of short, a few weeks back I changed the clutch cable on my 1990 Digi2 8v golf. In doing so I obviously rattled the loom around a bit and opened up all the dodgy "twisted together" connections left behind by previous owners removing immobilisers. So it wouldn't give a spark at all. Unwound the loom and soldered up/heatshrunk all the bad connections - sparking happily again. Problem now is, It'll start fine and run for about 3 or 4 seconds at idle before it dies on me. If I touch the throttle it dies pretty much straight off. During the few seconds it's running it idles 100%, sounds perfect. When it dies, it sounds like a fuel cut more than an ignition cut - tried running a known good fuel pump straight to the fuel rail/ FPR from a bucket of petrol - no change, so it ain't the fuel pump or lines. Tried swapping the ECU, Ignition module, AFM, coil, FPR, coolant temp sensor etc. from my other (running perfectly) 8v (same year/model) - no change. Ignition timing (as set statically)/cam timing are spot on. Any suggestions? The only thing I can think of is that it's fittted with a Thatcham approved immobiliser - a pretty old one. I think the thatcham ones cut two circuits - one is the starter, because it won't crank unless I disarm it. The other one could be ignition or ECU power - but I assume it's working right, because it works fine on the starter cut function. I also can't see why the immobiliser would let whatever else it cuts run for a few seconds before it cuts it out, either - so I don't think it is the immobiliser at fault. If I hold the key in the "start" position for a while (30 secs or so) it'll do it's usual "3-4 second idle then die" routine first, then every couple of seconds it'll "try" to start, with a few splutters before going back to plain cranking and no starting. Have to admit I'm stumped with this one - I've never taken a car to a garage in my life and don't intend to if I can help it, but I'm at my wit's end! The car was running 100% before this happened.... So, any suggestions before I roll it down the road into the nearest Nunnery and torch it?
But would that let it run for a few seconds before quitting? Posted the same question on your forum BTW - was hoping for some expert advice... Will give the ign. switch a crack tomorrow anyway...... cheers!
Tried several different bosch rotors/dizzy caps/ht leads on it (am I the only person that hoards old ones? I swear I have a cupboard full of them ) - still no difference! Like I say, I'm stumped by it, I can't see how it can run perfectly for a few seconds and then die, given that the fuel is there, and it's sparking like a good'un - does the Digi 2 ECU do anything unusual on initial start that might explain it running for a wee bit?
Can you not locate and bypass the immobiliser to rule it out?? Probably just a relay acting as a cut anyway.
The whole loom has been unsleeved right back to the ECU connector, any duff connections have been properly soldered and done with heatshrink tubing, all cracked wires have been spliced in with silicon insulated high-temp stuff instead.......
That's what I'm going to have to do soon - but I just know it's going to be something really fucking obvious that's been staring me in the face the whole time causing the problem! Any relays are inside the immobiliser, so it's not an external relay causing the problem. If it wouldn't start at all I could understand, but the fact that it runs like a dream for a few seconds has me totally befuddled. (That word sounds a bit gay, please substitute "fucked up" in it's place).
Hello my born again friend. While I look at the current flow diagrams for you, quick question. Have you tried it with the ISV unplugged or the pipe crimped? Just wondering if it was going fully shut/open and causing the stalling.
Yup, tried it with the ISV totally out of circuit, and the pipe plugged...... it's bizarre, I've never been unable to fix anything on a MK2 before no matter what the fault - but apart from 800g's suggestions which I'll have a go at tomorrow, I have tried everything. Been over the whole thing with a propane torch for vacuum leaks, swapped over every swappable component with the other GTi. The ISV is definitely working, too - if I unplug it it won't hold a steady idle, but plugged back in it'll idle perfectly for those few seconds....
800g's suggestion sounds promising but as the coil is also fed from the ignition switch why does it still run for a few seconds? Also have you tried a different TB in case the WOT and Idle switches are playing up?
Yup, both switches are fine and dandy right back to the ECU connector. I've tried jumpering the ECU relay and the results are exactly the same. I' have in fact tried everything I can think of, replaced everything I can think of, and still no go........
Well i can say i know what is wrong!!! You've pissed the devil off and he now lives inside your ecu and simply fucks with you whenever you try to start it!!
It could be the ignition switch if a bad connection gets hot enough it can cause open circuit which cause the engine to die after a few seconds then restart when the connection has cooled down, it could also be a dry joint on the connections you've soldered, not saying your crap at soldering but i do hundreds and get the odd dry joint.
Nah Matt, they were all just copper wire - weaved together then soldered, no PCB stuff. I'm hoping it's the switch - that'd be an easy fix.....
