Checking MJ Timing
Turbo Mini Forums

I have just been out to check my timing to ensure that the engine is doing as MJ is telling it to and I just wanted to check I have the right theory. I have never used a timing gun before, but I read a good few websites before proceeding but I wanted to check I've got it right!

I am using one of these snap-on guns.
http://buy1.snapon.com/products/diagnostic...me_mt2661ap.asp

The gun can do lots of clever stuff which I really dont need, so, I changed my MJ map to run 20 degrees advance in every box so it doesnt matter what rmp the engine is running at, set the gun to 40 degrees as I understand it reads double due to wasted spark (its certainly reading double rpm), pointing the gun at the crank wheel and the mark is a few degrees off the zero marker.

Changing the gun to 44 degrees shows the timing mark bang on zero degrees on the engine.

I've then changed the sensor position in the MJ software to -2 and now the engine mark is spot on zero with the gun set to 40 degress and the MJ showing 20.

Is this a good method or have I got something wrong somewhere?

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

funnily enough I was thinking this exact same thing just yesterday, i was going to do a similar thing by checking the actual fixed timming from the edis unit with the MJ unplugged (should be fixed 10degrees on edis only) then double checking it using your method of a single map value.

Didn't realise the gun would read double due to wasted spark though!

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.

I could be wrong but I didnt see the point in checking the edis timing at 10 degrees because if its out there isnt anything you can do about it...?

The trigger offset value is within the MJ software so I thought I might as well check the timing with that running rather than the edis on its own.

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

Your right,

On the ford the edis gives out 10deg, but its unlikly you'll get the bracked bang on easily,

best bet is to get it closeish and then trim the megajolt to be bang on.

no I understand that, but checking it on the edis only means you wouldn't HAVE to make a single value map, you could just measure the deviation on edis only, then make the adjustment in megajolt. then, on idle with the jolt plugged in, measure real time advance with a gun, and check it matches the value displayed on the screen!

Either way, I think we're all on the same page, and agree'd it'll work.

now I just need to get my USB - Serial adaptor to work :(

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.

So is this a confirmed method? due to it being a wasted spark you have to half the values?

yes!

that sounds like what i done, didnt have a clue, just point the gun with roughly dubble whats on the map there its is. oh saying that i got my map of oneeyed, all though its based on a metro turbo

ive just got a standard metro turbo map, i dont really know what to do with it but coupe is going to help me a bit when were at coombe.

Thank you, i will sort the timing out tomorrow