Just starting out, need a little help,

General Megajolt Questions and Answers

Moderators: JeffC, rdoherty, stieg, brentp

Post Reply
manx1641
Posts: 4
Joined: Fri Dec 08, 2006 9:38 pm

Just starting out, need a little help,

Post by manx1641 »

Hi everyone, i've installed megajolt on my vw type 1 1641cc engine, it's all running ok with the default map but i now want to start tuning with my own map,

firstly my trigger sensor is mounted so when the engine is at tdc the missing tooth is 90deg ahead, this appears to be the wrong way round according to the instructions, the engine still runs though, is this because the leads are also crossed over? i installed edis well over a year ago then built a new engine, but i do remember having to swap the leads around to get the old engine to run, will it affect the advance?

Also just a few basics for making a map, in general should i increase the advance as the rpm increases and decrease with load? or is it more linked to the amount of fuel required, hence as the engine leans out at higher rpm the advance decreases?

sorry for the stupid questions, i'm just trying to walk before i run!

MartinM
Posts: 433
Joined: Sat Aug 27, 2005 12:08 pm

Post by MartinM »

Fixing the VR sensor being the wrong side of the missing tooth by swapping the plug leads is fine. Done it myself on my install :oops:

For a map in general:

- advance increases as rpm increases - easy to understand

- advance decreases as load increases
...for TPS that means that advance is greater at low throttle (ie nearer the 0% end) than advance at full throttle (nearer the 100% end)
...for TPS that means that advance is greater at low MAP (ie small numbers of kPA) than advance at high MAP (large numbers of kPA)

Have a look at the default map in the MJLJ - it shows these features

manx1641
Posts: 4
Joined: Fri Dec 08, 2006 9:38 pm

Post by manx1641 »

Thanks thats great, good to know i'm on the right path, cheers.

DannyP
Posts: 417
Joined: Sun Apr 09, 2006 3:48 pm

Post by DannyP »

Are you map or tps sensor?

If tps, try mine:

http://www.autosportlabs.org/viewtopic.php?t=1772

I started with a map that copied the 009 distributor, and went from there. I am on version ten of it now, just minor tweaks around part throttle and idle.

Post Reply