Need a little help getting timing/spark set right

[94teggy]

Alrighty so at the hands of hockey930's friend Rob and hockey's expert ground wire failure detection (and my supervision of course :-P) Megasquirt-n-Spark is installed in my '89 740tic woot! However, we had some funky issues arise when it came time to initially set the timing. For some reason, no matter what settings Rob would enter in MS, when checking the engine with the timing light it constantly showed around 10 degrees AFTER top dead center.

Any ideas as to why he could not get the timing to change at all?

Here's the MSQ file from my box...it's a file that was used on the Lolwagon while it was here in Charlotte before it died. We used this file because it has a very similar setup to my 740...the only difference is the block mount distributor vs my head mount distributor and it was a B230F motor vs my B230FT (so slight difference in compression ratio)
LINK (http://www.mediafire.com/?sharekey=f414ba8620ddd1088ef1259ff1b60e81e04e75f6 e8ebb871)

[JohnMc]

Isn't there a setting on the spark to hold it at a fixed angle? Make sure that's turned off. I think it's supposed to be 10 deg BTDC, but perhaps you have your trigger angle wrong.

[94teggy]

I'm pretty sure we tried that and nothing changed :-( ....I'll go give it a shot though and see if that gets me anywhere

[JohnMc]

I don't have MT on my work laptop, so I can't look at the MSQ.

[hockey930]

I think they set it fixed and then tried to adjust the triger angle. When they adjust the triger angle the timing mark does not move.

[JohnMc]

Ah, makes slightly more sense. Is this using wheel decoding - 2.4 crank position sensor and flywheel?

[94teggy]

No, it's with the stock LH2.2 head mounted dizzy with hall sensor

[Turbo B]

this pretty much sums it up. I set 0 degrees for a fixed timing setting, and then tried to change the trigger angle and couldn't get it to move. Megatune showed a commanded 0 degrees but the timing light showed about 30 retard no matter what the trigger angle was.

[linuxman51]

as I told hockey yesterday..

One of two things has happened here:

1) You wired the distributor input up incorrectly

or

2) You have the spark output defined incorrectly in the msq.

I can't check the msq right now since I'm at work, but those two things are just about the only two things that will cause ignition strangeness along those lines.

Of the two, I would hedge my bets on #2.

Distributor output for trigger return is either fidle (default) or LED17 (i think. the one closest to the serial port).

If you set the board up for the LED output but the ms is firing the fidle, you would see this type of behaviour since the led would be indicating a trigger event from the distributor.


Now, once you have sorted that issue out, and you find yourself unable to set the correct trigger angle without the engine trying to die/run backwards/etc as you approach what 'should' be the trigger angle, then you have also saddled yourself with #1.

In which case I can really only say "Shoulda read my writeup" :-P

[Turbo B]

Thanks Kenny, I too expect something dumb to have happened.

We are triggering off of LED17 on the board, and when I left yesterday, Megatune was set to LED17 as Spark output A.
HOWEVER, I did look at the voltage display in megatune yesterday and ignore it for 5 hours before deciding to relocate the ground away from the stock ECU connector- PRESTO - we got spark.

Volvo stock wiring impresses me about as much as stock Lucas wiring on MGBs. If I didn't run the wire, there is no reason to trust it.

Thanks again for the help.
Rob

[hockey930]

bump