Megasquirt EFI conversion

[opethmike]

Here is how I did my conversion to EFI.

[Spittybug]

Good write up Mike.... gives people another reference to consult.

I'm going to suggest that we get Sean to move this over to the EFI area though where we want to build up the entire body of EFI knowledge in one place. Make sense to you?

[opethmike]

Works for me.

[Spittybug]

Mike, I noticed that your warmup enrichment values are significantly higher than mine. Did you get to them from trial and error in your colder climate? I know that I have mine extend to too high a temperature (WUE stays on too long) and will be adjusting that, but since I seldom have really cold mornings (today excluded, but still mid 30's) I don't really have the opportunity to find out what the cold end of my curve should look like.

How about your AFR table? Based on anything other than gut? Mine is flat across the board which I know is not optimal, but I was looking for guidance on where to adjust it to.

[opethmike]

Good catch on the WUE - I had initially run with WUE set to the same values you have. But I found that I was getting very lean AFRs from them; 15.5-17.8 or so.

The AFR table is based on the AFR table suggested in the tuning section of the MS documentation, but with slightly richer values as that is what the PRV (at least mine) seems to like. With how nicely my car drives, they seem like good values.

[Spittybug]

I tried your values and I ended up wayyyyy rich, so I backed off. Amazing how different climates and different cars behave.

[opethmike]

My WUE definitely still needs some work. The car does start quite rich, but settles nicely after 10 or 20 seconds of running.

My accel enrichment might need work too. As far as I can tell, its enabled, but when I jam on the loud pedal, I notice neither bucking (too lean/too rich), nor any particular change in the feel of the car.

[dmc6960]

You folks with standard cams have it good. I cannot reliably use the MAP setting for acceleration enrichment. Too much natural bounce in my readings. Being that I only have a MS 1 processor, I also cannot do some of the functions everyone else can. I only have the option of 100% TPS or 100% MAP. I have decided to upgrade to MSII in the spring though. Then I can hopefully get a reliable 50/50 for that.

[opethmike]

How come you chose MS1, out of curiosity?

[Bitsyncmaster]

My WUE definitely still needs some work. The car does start quite rich, but settles nicely after 10 or 20 seconds of running.

My accel enrichment might need work too. As far as I can tell, its enabled, but when I jam on the loud pedal, I notice neither bucking (too lean/too rich), nor any particular change in the feel of the car.

I tested our engine (stock) for cold start and it does run around 10 AFR when first starting. With your LC-1 wideband, it takes about 15 seconds to go closed loop.

[dmc6960]

How come you chose MS1, out of curiosity?

Cost. At the time I was on a tight budget as I was also spending on a complete suspension rebuild at the same time. Total EFI costs were less than $1000. Other than a few lacking features which arn't totally necessary, the MSI with Extra firmware has been more than enough for my car now for 2 years, a cross country drive, and at least 15,000 miles.

Now I can spend a little extra on a MSII daughtercard, new throttle body, and another O2 sensor and heatsink.