Engine surge with indicators..........

[hudson44]

......... Yes that's correct. Just make the 1200km round trip from Melbourne to Robe and back and although the car hummed and served me well the whole way, i discovered that the 3.0lt would surge in time with the indicators.

To me it seems that the ignition power is surging with the indicators however with any other electrics (lights etc) its fine. Also using the hazards has no effect on the engine. I'm suspecting a bad earth in the indicator circuit or a fault with the aftermarket alarm system which cuts the ignition and uses the indicators to signal.

Has anyone else had a similar problem? Just thought i'd ask before i go exploring.

[-Scott-]

Can't really help - but, for a long while, the tacho in my Sigma would fail in hot weather, but still work in time with the indicators. Now it simply fails most of the time, except for cool mornings.

I'm waiting for total failure before I try to troubleshoot it.

[hudson44]

Yeah, it's got me a bit buggered. Haven't started testing as yet but thinking about it opens up a wide variety of possible causes. It's funny that its only the indicator circuit that trips it out. I'm thinking something along the lines of the ECU supply voltage dropping (whatever the fault may be) or the ignition voltage dropping, as it runs through the immobilizer as do the indicators and there may be some sort of short within the immobilizer module which is dropping the link made to the ignition.

Might try bypassing the immobilizer and checking the ecu earths and go from there. The speedo stopped working for a week a few months ago, but hasn't missed a beat since and wasn't affected by the indicators.

If i have the ignition on and use the indicators, the red "display lights" will dim as the indicator does which makes me think the drop in ignition power is causing the surging.

[NJV6]

Interesting!

Of no use but may be of note, when I operate my winch (with no load but it still pulls a good current) even at idle the engine revs do not change even though my volt metre drops to about 10.

[hudson44]

Problem sorted. The immobiliser was u/s and giving low ignition power. I bypassed the immobiliser and it's running fine.

[date]

Question: How did you bypass the immobiliser? I would expect that the ECU would think that the car was being stolen and somehow refuse to allow it to be started. What use is an immobiliser if you can bypass it?

[hudson44]

Question: How did you bypass the immobiliser? I would expect that the ECU would think that the car was being stolen and somehow refuse to allow it to be started. What use is an immobiliser if you can bypass it?

Its an aftermarket one which i intalled myself. I cut the ignition to run through it as the immobiliser side of the module. It must be shorting out internally and not supplying enough current to the ignition. It does still run the doors etc so i might cut the ignition supply at the control relay which has less current as it still has no resistance (closed circuit) but may have been too much current flow for the module.