[UcatchMyDrift?]

Hi, the cars running on a bofi basemap (ms3 mini) . Just fitted a set of ev14 injectors. Hopefully ive entered in the settings for them in tuner studio correctly, including the dead times.

Wondering if there is a way of richening up the whole map as it looks a bit lean whilst cruising? Im not really accellerating more than the absolute minimum until its tuned in a week and a half, but want to have it running as safe as possible until then. See below:

Also, when starting the car, it is very lean to start with, then after a while it settles. This was the same before i fitted the ev14's, just not as bad, and it only did it when cold starting. With the new injectors its every start.. Would changing the initial enrichment help with this?

Thanks 👍👍👍

 

[UcatchMyDrift?]

Looking at the ms3 instruction manual, possibly, after start enrichment, after start enrichment taper, and warmup enrichment?

 

[Martin Y]

Yeah, the O2 can get a bit confused by however much cranking fuel is going through but after the engine starts the O2 should be able to give sane readings within a few seconds. When the engine is turning faster than whatever startup RPM you have set, the MS decides it's running and so it switches from injecting cranking fuel to injecting the normal map amount of fuel plus* the afterstart enrichment plus* the warmup enrichment. Afterstart tapers off over either a set amount of seconds or a set number of engine revolutions (you can choose) while warmup tapers off as you'd expect, at the coolant temperature rises. If it's lean after starting then I'd begin by adding afterstart enrichment, and if you track how that changes over, say the first half minute to a minute, then you can have a go at adjusting how fast or slow it tapers off. (That's assuming that the basic fuel map is already tuned about right in the cells around idle, including the faster idle speeds it'll use when cold. And that's easy to set by letting autotune do it after the engine's warmed up.)

* I say "plus" but maybe I should say "times" as I think both are a percentage addition, so really a multiplication of the stock amount. Can't exactly remember what the options are but I think the default is that it adds a percentage.

 

[UcatchMyDrift?]

Yeah, the O2 can get a bit confused by however much cranking fuel is going through but after the engine starts the O2 should be able to give sane readings within a few seconds. When the engine is turning faster than whatever startup RPM you have set, the MS decides it's running and so it switches from injecting cranking fuel to injecting the normal map amount of fuel plus* the afterstart enrichment plus* the warmup enrichment. Afterstart tapers off over either a set amount of seconds or a set number of engine revolutions (you can choose) while warmup tapers off as you'd expect, at the coolant temperature rises. If it's lean after starting then I'd begin by adding afterstart enrichment, and if you track how that changes over, say the first half minute to a minute, then you can have a go at adjusting how fast or slow it tapers off. (That's assuming that the basic fuel map is already tuned about right in the cells around idle, including the faster idle speeds it'll use when cold. And that's easy to set by letting autotune do it after the engine's warmed up.)

* I say "plus" but maybe I should say "times" as I think both are a percentage addition, so really a multiplication of the stock amount. Can't exactly remember what the options are but I think the default is that it adds a percentage.

Thanks for the reply 👍👍
I increased the fuelling for the warmup enrichment which seems to have done the job for cold starts, which is great.

I tried increasing the fuelling for the afterstart enrichment, for example as an experiment, i set 10deg C to 80deg C to 40% more than the base amount (i think 50% is about the max it reccomends). But unfortunatley it hasnt made the slightest diffrence. Runs very lean on warm startups for a minute or so. I didnt touch the afterstart taper.
The idle is a bit high and also takes quite a while to settle. I dont have the autotune option as its going on a dyno in a week or so and didnt bother buying it.

I havent touched any of the basic fuelling maps at all, including the idle ones. But seems strange to me that adjusting the after start enrichment didnt do anything. But then, ive only been messing with this stuff for about 2 days lol, so i know nothing anyway 🙄

 

[Martin Y]

Lean warm restarts are often caused by heatsoak. The air temp sensor gets hot and takes time to cool down after restarting. During that time the ECU thinks the incoming air is really hot, so will be low density so it reduces the fuel to match.

On my MS2 the workaround is to tick the box to "ignore IAT at startup" and that gives it a useful few seconds of not being fooled by the hot sensor.

 

[dadbif]

ISTR there is a cold start feature using auto tune?

 

[UcatchMyDrift?]

Lean warm restarts are often caused by heatsoak. The air temp sensor gets hot and takes time to cool down after restarting. During that time the ECU thinks the incoming air is really hot, so will be low density so it reduces the fuel to match.

On my MS2 the workaround is to tick the box to "ignore IAT at startup" and that gives it a useful few seconds of not being fooled by the hot sensor.

Ahhh, ok, thanks. Would that the be option for me that says "ignore MAT correction during ASE"?

 

[UcatchMyDrift?]

ISTR there is a cold start feature using auto tune?

Hi, dont have autotune, and cold start is ok now thanks...

 

[UcatchMyDrift?]

Also, something unrelated, i bought an aftermarket fuel filter from my local car shop, was going to fit it soon, but was thinking, should i have gone for a genuine mazda one? Anyone have a turbo mx5 using a cheap fuel filter? Dont want those injectors to be starved of fuel - that could be bad!

 

[Martin Y]

Ahhh, ok, thanks. Would that the be option for me that says "ignore MAT correction during ASE"?

Yes, that sounds like it.

 

[Martin Y]

Also, something unrelated, i bought an aftermarket fuel filter from my local car shop, was going to fit it soon, but was thinking, should i have gone for a genuine mazda one? Anyone have a turbo mx5 using a cheap fuel filter? Dont want those injectors to be starved of fuel - that could be bad!

Well I've used pattern parts and never had a problem with a fuel filter, for whatever that's worth.

 

[UcatchMyDrift?]

Annoyingly, this morning, cold start was worse! Bad hunting going from lean to rich. Hmm.

 

[UcatchMyDrift?]

Hi, dont have autotune, and cold start is ok now thanks...

Spoke too soon lol.

 

[Martin Y]

I think for a kickoff I would get the fuel map tuned in the idle area. After a drive let it idle and then tweak the cell of the map it's idling in to get the fuel right (and blend in its neighbours too). If you give it the faintest bit of throttle to raise it closer to cold idle speed you can trim that cell too.

Once you know the fuelling isn't going to do anything weird just because the idle speed is gradually coming down after a cold start, you can look at what the O2 is doing after a cold start and compare it to the amount of extra fuel that's going in.

 

[UcatchMyDrift?]

Thanks,

I think for a kickoff I would get the fuel map tuned in the idle area. After a drive let it idle and then tweak the cell of the map it's idling in to get the fuel right (and blend in its neighbours too). If you give it the faintest bit of throttle to raise it closer to cold idle speed you can trim that cell too.

Once you know the fuelling isn't going to do anything weird just because the idle speed is gradually coming down after a cold start, you can look at what the O2 is doing after a cold start and compare it to the amount of extra fuel that's going in.

Thanks,, i think thats a bit beyond me atm,, but The cars been sitting for a number of hours so i just tried again. I dont think i upped the wue enough in the 30-40 degree c range, had a fiddle and this time all is good. But to be sure ill need to wait until tomorrow to be sure. Going to go for a drive now and check if the hot start works now too. 🔥👍

 

[UcatchMyDrift?]

Well, got the car up to temp and seems to start ok after telling the ecu to ignore the iat at startup. Hopefully in the morning itll start ok too! If so, ill be good until a week tuesday when its getting tuned.. 👍

 

[UcatchMyDrift?]

Started ok this morning. Starts ok after being warm, but still very lean after startup when hot. But ill leave it at that untill its tuned. Barely using the car anyway. Hopefully the tuners will sort it 🙏

 

[UcatchMyDrift?]

Well,, spent the morning getting the ecu mapped on the dyno, and is all done! 235bhp/210f/lb (asked for 230bhp, so that'll do me nicely 😃). Feels awsome, pulls real good all the way to the limiter, very pleased after many hours work! And a big thank you to those that have helped me on here with many questions over the last couple of years or so 😁👍👍👍👍👍
Cant believe it.
Time for some bigger brakes (mk2.5 sport cali's in the post arriving soon) 👌