Shuld I replace ICU?

[Donald360]

Took the van for a couple of runs after putting the engine (1985 1.9 DG) back in and all seemed ok, perhaps running a little hotter than before. Anyway I drove to work (13 miles) without a hitch, but when it came time to drive home again the van conked out a couple of times after only driving a few hundred yards. It then started up again and drove for a few miles before dying and I managed to coast onto a quiet side road. Engine turns over well enough but but nothing else, so I got the AA out.He was able to establish that there was petrol but no spark, coil seemed ok. We then found a broken wire, the red one from the ICU. Connected it back together, but still no spark. AA chap reckons its the ICU and I got a tow home.

The question now is, do I replace the unit? Pretty expensive new - should I source a second hand one? I've also read that many people simply by-pass the unit, how do I do this and is it advisable?

Cheers
Donald.

[BOXY]

Disregard this post. I didn't know a DG engine didn't have an idle stabilizer.


The two plugs on the idle stabilizer control unit simply plug together. Try this first and if it gets the engine running . If you've still got no spark then the ECU or Hall sensor are probably the cause. You can sort of test them to try to pin down which one is the most likely.

This post might help.
https://club8090.co.uk/forum/viewtopic.p ... ilit=+hall" onclick="window.open(this.href);return false;

[toomanytoys]

ICU (amplifier really as it isnt a control unit) and ISU (idle stabilisation unit) are 2 different things.. 1.9DG's dont have the ISU..
If it the amp thats blown then they are about 30 quid, but good news is that many golfs/passats and audis use the same unit.. so a used one should be cheap..

Hall sender is a different matter..

You need to estanlish whats gone wrong.. as any part of the loop will result in no spark.. systematic approach to fault finding needed rather than replace the bits till its fixed..

[Donald360]

Tested the hall sender and it seems ok so it looks like I need to get a new ignition unit. Latest problem now is my battery keeps draining. I checked with the meter and pulled each fuse to try and find the dodgy circuit but no difference. Tried disconnecting the leisure battery in case it was a fault with the split charger, but no difference. Now I'm out of ideas. Any help appreciated.

Cheers
Donald.

[Donald360]

Ordered a new ignition amplifier from Brickwerks and fitted it this morning. It's a slightly different size from the unit I removed so its not attached to the engine bay yet. But guess what, I turned the key and the engine burst eagerly into life - result! All I need to do now is figure out why my battery is draining away. There must be some leccy genius out there that can suggest a cause that is not affected by pulling fuses.

I need to drive to a training course tomorrow. I'm wondering if I just disconnect the battery when I pull up for the night...

Best
Donald.

[BOXY]

What reading are you getting when you connect the ammeter in series with the battery?

Maybe the battery is shot? After it's been on charge leave it disconnected for 12 hours and then test it. After 12 hours any surface charge should have dissipated and the meter should read 12.6 volts. If it's as low as 12.2v that means the battery is only at 50% charge.

[Donald360]

Yes. Testing the battery is the next thing on my list.