I fitted a 123tune to my BMW m10 4 cylinder and cannot track down an intermittent problem.
When it is cold the ignition completely cuts out for a second, only with a light throttle, around 1800rpm.
I have triple checked the earth, the wiring, changed the coil and the coil lead to the distributor.
Once it is fully warmed up there is no problem.
I know it’s the ignition as the rev counter dies for a second at the same time, plus I have changed the carb set-up once.
Anybody experienced any kind of temperature related failure within the 123tune?
Cheers, Nick
[img]http://www.m2bmw.com/cheironPics/DSC_0088.jpg[/img]
Hi Nick
I have similar annoying hiccups in my 1971 Fiat 124 Spider, after installing the 123 system. I believe to have traced the problem to the voltage regulator (Charging circuit) putting out voltage spikes in excess of 15v, thereby triggering the voltage protection of the 123. This could well be the case with yours -. during warm-up - when charging demands are higher.
After installing an electronical regulator the ignition cut-outs (and voltage spikes) are much more infrequent - but are alas still happens intermittently.
I now intend to install a voltage limiter on the ignition lead to try eliminate the problem.
In short: use a voltmeter to check voltage at your regulator around the troublesome RPM, and check that voltage does not exceed approx. 14.4v.
Hope it helps - Sven
PS: Otherwise a brilliant system - faster start ups + more responsive and powerfull engine.
Tip: I have increased plug gap to almost double at 1.2mm
Thanks Sven,
I shall give that a go. I'm using a later 3 series alternator with a built in voltage regulator, but it's still possible it's not working properly.
Cheers, Nick
In some cases a very unstable boardnet voltage can cause misfires. The 123ignition is protected for high voltage peaks and goes in protection mode for a split second when a spyke is detected. Most of the time this error occurs when the car battery is charged full again and the voltage regulator starts to work.
This problem can be caused by a broken alternator / dynamo or bad voltage regulator. Unfortunately this is impossible to measure with just a standard voltage meter because we talk about high voltage spikes of micro seconds.
You could easily test this to drive a while without working alternator / dynamo. Use a fully charged car battery and make sure no other important systems are driven by the dynamo belt, like the coolant pump!!!
