help with starting a hot engine

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luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

help with starting a hot engine

Post by luciano e46 brazil »

my e46 2.5 dme ms43 injectors of 52 lbs bosch 100% ethanol from sugar cane, it starts very cold, when hot it starts with a lot of fuel the injector time at the beginning goes to 16 mls I've looked in all the tables and I can't find anything that is At this value, hot after idle it runs very well but the problem is the hot start, could someone help me Any opinions are welcome, I've been dealing with this for months
Renovelo
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Re: help with starting a hot engine

Post by Renovelo »

Can you upload your tune so it’s possible to see how it’s been modified so far?
luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

Re: help with starting a hot engine

Post by luciano e46 brazil »

I'm not able to post the file here, is there an email I can send it to?
Renovelo
Site Admin
Posts: 310
Joined: Thu Aug 08, 2013 7:02 pm

Re: help with starting a hot engine

Post by Renovelo »

Renovelo
Site Admin
Posts: 310
Joined: Thu Aug 08, 2013 7:02 pm

Re: help with starting a hot engine

Post by Renovelo »

It seems you're on the correct path by modifying IP_TI_CST, IP_TI_CAST, and IP_TI_TCO_WUP. However, is there a reason you didn't scale all of the proper fuel tables by your new injector scalar? It appears you only modified the fuel values for some of the temperature correction maps around warmer temps. Otherwise, the rest of the tables are completely stock.

See here for more details: https://www.ms4x.net/index.php?title=Si ... or_Scaling
luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

Re: help with starting a hot engine

Post by luciano e46 brazil »

Yes, I didn't modify them all because I'm learning to deal with it, I'm still going with caution, the abbreviations of the table names make me confused, but I'm getting used to it, one more question would be to use the voltage input of one of the post cat probes to input a 0 to 5v signal from a wb reader and have the value displayed in the log as a lambda value
luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

Re: help with starting a hot engine

Post by luciano e46 brazil »

I didn't find these tables

ip_ti_cast__tia__tco -
ip_ti_cr_cst__cyc__tco -
ip_ti_cr_cast__cyc__tco
Renovelo
Site Admin
Posts: 310
Joined: Thu Aug 08, 2013 7:02 pm

Re: help with starting a hot engine

Post by Renovelo »

Search for these instead and you'll find them:
  • ip_ti_cast
  • ip_ti_cr_cst
  • ip_ti_cr_cast
luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

Re: help with starting a hot engine

Post by luciano e46 brazil »

I adjusted the start and start tables and it continues to shoot a lot of fuel at hot start, it only starts by pressing the accelerator pedal, I don't know what else to do with it
Renovelo
Site Admin
Posts: 310
Joined: Thu Aug 08, 2013 7:02 pm

Re: help with starting a hot engine

Post by Renovelo »

What about IP_TI_TCO_WUP? With this parameter, you can target a specific coolant temperature and perhaps dial it back a bit.

There is another similar parameter which may come into play called IP_TI_TCO_WUP_IS.
luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

Re: help with starting a hot engine

Post by luciano e46 brazil »

I'm going to make a log of the cold start and the hot start to see if you can identify where this high injector time is coming from, if I leave it set to start very cold it starts very hot, if I set it hot it doesn't start cold at all
Renovelo
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Posts: 310
Joined: Thu Aug 08, 2013 7:02 pm

Re: help with starting a hot engine

Post by Renovelo »

Sorry, we can’t provide in-depth support for “how” to tune. We can provide insights, but ultimately the details are up to you. We do this for our protection as well as yours.
luciano e46 brazil
Posts: 11
Joined: Thu Apr 11, 2024 10:48 am

Re: help with starting a hot engine

Post by luciano e46 brazil »

I found what could be causing this problem but I don't know how to solve it in the log I noticed that at startup the maf value goes up which is why the injection time is high, any tips on what could be causing this
Renovelo
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Posts: 310
Joined: Thu Aug 08, 2013 7:02 pm

Re: help with starting a hot engine

Post by Renovelo »

The MAF reading only surges during a hot startup, but not during a cold startup?
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