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Old 04-07-2010, 02:28 PM   #1
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Default Too lean on warmup?

Hello all, another noob question for you all.....

1991 MX5
running NA
DIY MS1 V3.0
Tunerstudio

Using the DIYautotune basemap, I notice that it idles when warming up at AFRs of about 13:1 and as it reaches full operating temperature this steadily drops to around 11:1 (this sounds backwards to me - what are the warmup enrichments doing???)

So I thought id tune the idle for AFRs of 15:1 with the engine off warmup (full operating temp), which was pretty easy to do by dropping idle areas on the VE table by about 15 points. Now when I start it from cold, it idles at 16-17:1, which is completely backwards as it was before I started tuning, what is going on here? Needless to say, I tuned it back so that it idles rich when cold and even richer when hot - as before.

So basically, what are my warmup enrichments doing?

I looked at the warmup wizard whilst the engine was warming and watched the coolant temperature cause the enrichment table to read off a lower percentage, so I know its doing something!

I also did a bit of autotuning (just around the block) but dont feel confident about tuning untill I get this issue sorted

Many thanks
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Old 04-07-2010, 02:40 PM   #2
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Sounds like you need less fuel at idle and more warm up enrichment.
Look for around 13.5:1 at idle.
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Old 04-07-2010, 03:46 PM   #3
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Quote:
Originally Posted by paulj View Post
So I thought id tune the idle for AFRs of 15:1 with the engine off warmup (full operating temp), which was pretty easy to do by dropping idle areas on the VE table by about 15 points. Now when I start it from cold, it idles at 16-17:1, which is completely backwards as it was before I started tuning, what is going on here? Needless to say, I tuned it back so that it idles rich when cold and even richer when hot - as before.
You've got the right idea by adjusting the idle VE table cells while the engine is fully warmed up. Put the VE table numbers back to what they were after you did that. Then to adjust WUE you will have to let the car cool down fully, like overnight.

Warmup enrichment gives x% fuel at y CLT temperature. If say at 100* CLT you have a WUE of 120%, that means MS is injecting 20% more fuel than would be dictated by the VE table alone. In MS1 it tapers down so there is 100% of your VE table-based fueling (no enrichment) at 160* CLT.

So starting from cold, open up the warmup wizard. The arrow will move to point at the row your CLT is at, and then you adjust the WUE % to whatever it needs to be to give you a reasonable AFR.

I don't know what you mean by the table "reading off a lower percentage" but all of the WUE percentages should be ≥100. If any of those numbers are <100 the car will probably exhibit some interesting behavior. It happened to me once when my msq got corrupted. Took me a minute to figure out WTF was going on LOL.
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Old 04-07-2010, 04:14 PM   #4
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Originally Posted by ScottFW View Post
You've got the right idea by adjusting the idle VE table cells while the engine is fully warmed up. Put the VE table numbers back to what they were after you did that. Then to adjust WUE you will have to let the car cool down fully, like overnight.

Warmup enrichment gives x% fuel at y CLT temperature. If say at 100* CLT you have a WUE of 120%, that means MS is injecting 20% more fuel than would be dictated by the VE table alone. In MS1 it tapers down so there is 100% of your VE table-based fueling (no enrichment) at 160* CLT.

So starting from cold, open up the warmup wizard. The arrow will move to point at the row your CLT is at, and then you adjust the WUE % to whatever it needs to be to give you a reasonable AFR.

I don't know what you mean by the table "reading off a lower percentage" but all of the WUE percentages should be ≥100. If any of those numbers are <100 the car will probably exhibit some interesting behavior. It happened to me once when my msq got corrupted. Took me a minute to figure out WTF was going on LOL.
Thanks for the replies! So its basically a case of beefing up my warmup enrichments then I just kind of assumed I wouldnt have to mess with the percentages at all from the basemap.

What I meant from "reading off a lower percentage" was as you said, the percentage value gradually decreasing from around 120% down back to 100% in the warmup wizard.

I will have a play with this tomorrow and update here how I got on, hopefully its as simple as this!

Thanks
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