Megasquirt - starting

[gifdy]

Does anyone have MS fitted and has got involved in tinkering with it themselves, rather than use a pro tuner ? One of the reasons I went with MS was I wanted to learn a bit about it myself. It would be great to hear other people's TVR experiences.

My first aim is to improve the starting. At the moment I need to have the accelerator down for it to start. Doing some research ( the back up material online is pretty good ) it looks like the MS injects a set amount of fuel ( temp rated ) when cranking. Adding throttle is letting in more air so presumably I need to reduce the amount of fuel. What are others curently at ? Around 15-20 degrees C I am at 270%.

[Grey Ghost]

If you post the same question in the Chimaera section you will be knocked down by the response based on previous threads about MS.

DAZ

[neal1980]

Get yourself to www.extraefi.co.uk and have a read of his tech articles / help.

I had a tinker with mine but was too difficult to hold the laptop when the turbos boosted up

[gifdy]

Walford said:

what does your voltage drop to when cranking
this afects injector open time

Is that right ? I would have thought it would be regulated. OK - one to check

[gifdy]

neal1980 said:

Get yourself to www.extraefi.co.uk and have a read of his tech articles / help.

I had a tinker with mine but was too difficult to hold the laptop when the turbos boosted up

Yep, I'm working my way though them. The youtube turorials are pretty good as well

[gifdy]

B-Reight said:

My settings (3.9 wedge) are:

Temp-Cranking PW%
10 - 276
24 - 251
31 - 226

with a req'd fuel value of 8.35ms

Have you got your idle valve doing anything at startup?

I'll need to check that. I reduced the crank fuelling from 270ish to 220% but no major difference. Need to keep tinkering. I appreciate each setup will be different but it's useful to hear how others have got on. Thanks !

[Bassfiend]

gifdy said:

Walford said:

what does your voltage drop to when cranking
this afects injector open time

Is that right ? I would have thought it would be regulated. OK - one to check

No - the injectors are fed directly from a (switched) battery + ... the ECU provides a ground for them to fire them. However the time that it takes an injector to open varies quite drastically with battery voltage.

I don't know whether the MegaSquirt has a table to map this against - the CANEMS that I have does - and the CANEMS automatically adjusts the time when it *STARTS* to open the injector so that it adjusts automatically for supply voltage variations (I would assume the MegaSquirt does too?)

Phil;