Opel Commodore GS/E 3,0 24V

[Wally]

So, where is the missing teeth in relation to that TDC mark? Sorry if you have said before.

Wally

[Anders_Karlsson]

The missing teeth are in bottom left of the picture.

Engine rotates clockwise.

11 teeth to the TDC-mark counting anticlockwise from the gap.

I also managed to take this picture.

Counting anticlockwise from the gap, i get leading edge of tooth 15 just at the edge of the sensor "eye" in the magnetic cranksensor.

That would suggest sensor position 90 degrees BTDC? Could also be 270 degrees if counting 45 teeth from the other way?

My settings in DTASwin is sensor position 60 degrees BTDC, and the engine runs ok with that?
It wouldnt run at all if the cranksensor was off by 30 degrees?

I think i posted my map back in the thread, dont know if its still there.

I will have to check my timing again, now that i know the TDC-mark is right.

[Roverdose]

90btdc. that's probably why your main ignition map is so low, and you were getting det. your adding 30gr advance to your whole map.

Drew

[Wally]

I agree with Drew, If you have 60 in DTASwin then there would already be 30 deg of advance plus what you have in the ignition map.

When you get the timing light on this you should see what is happening, put 90 in DTASwin and say 6 deg in the map and you should see your tdc bracket line up with your 6deg mark painted on your pulley (with the timing light is set to zero). Make sure there are no compensations active and then adjust the 90 figure either way to get the marks to line up.

Wally

[Anders_Karlsson]

I agree with what you say, makes perfect sense.

The main ignition map is set at 8 degrees in idle, but in reality its 38 degrees
No wonder my starter motor was getting bad, so much advance in cranking makes engine kick back violently.

Before i try anything else i will strobe the ignition with stock ECU and proper timing light, then i´ll install DTA again and strobe ignition before making changes.
If things get clearer i will try changing the sensor position and see what happens.
Should make the ign. map lower as you say, so nothing should break down i hope.

[Anders_Karlsson]

Strobed the ignition with a digital timing light.

With sensor position at 82 degrees BTDC, advance map set to 6 degrees at idle 850 rpm and timing light set to zero degrees i get the pointer at the trailing edge of the tooth marked 6 degrees.

If i increase the advance on the timing light to 6 degrees the pointer is at the trailing edge of TDC-tooth.

If i set sensor pos at 90 degrees BTDC, advance map at 6 degrees and timing light set to zero the pointer is halfway between the TDC-tooth and the first tooth after TDC.

So correct sensor position seems to be 82 degrees BTDC? Or is my pointer 2 degrees off?

Anyway, took it for a small testdrive with sensor pos at 82 degrees, otherwise unchanged map and engine seems to run fine. No rattling/detonation that i can hear.

Feels stronger and smoother than stock ECU so i guess it just needs some small adjustments to the map now.
It also makes a very nice intake sound, wich is a bonus

Edit:
Managed to take a picture of the markings, this is 8 degrees advance at 850 rpm.
There is a 0 mark on the tooth direct above the pointer.

[stevieturbo]

Not sure what you are saying.

Create a TDC marker. Then ensure that timing commanded ( ie timing displayed in real time info or dyno screen after any compensations ) is exactly what you are seeing on the timing light relative to the TDC marker.

[x30xe]

If real time info shows 6 degrees advance while running, and strobo shows that ignition happens 6 degrees BTDC then your offset is right.

82 degrees is good baseline for a Opel straight six (12v or 24v).

[Anders_Karlsson]

Stevie: as far as i can see my timing mark, strobe light and Swin says the same advance with cranksensor at 82 degrees.
Engine runs fine too, just need some small adjustents.

X30XE: excactly, that is what i get in realtime window and on timing light.
Guess you have done Opel CIH-based engines with DTA before?
Good to know im not alone

[x30xe]

Yes Anders, I'm pretty sure you've seen my CIH stories in opeltuners. Good luck with the Commodore !