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Jefferson.C

Lean Spot After Hot Start

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So just a quick rundown, this is my first time getting a vehicle to start and run with a plug&play system. R32 GTR Rb26 itb engine setup. Any advice in general if you have the time to look it over would be great! Keep in mind, it has not been tuned by my tuner yet, I am strictly driving around under 4500 rpm and max roughly 60% throttle for break in and basically just learning how to set it up myself. So far I've been very successful and extremely happy with this ECU.
One small problem I am having is this lean condition after hot startups. I understand it's probably from heat soak from fuel and stock location IAT sensor. It's quick and clears out once closed loop control comes into effect it seems. I tried some changes to the post-start enrichment and decay time but with little change. Cooler ECT it's not as bad. 
Thoughts here? 

 

apr19hotstart.llg apr17.pclr

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I tried going with a higher value in the Post start enrichment % in the 70-90 degree ECT and longer post start decay time (20 seconds) to see if having the decay timing longer then my closed loop lambda timer lockout (18 seconds) It helped a little bit. Still went into a lean condition but for a shorter amount of time.

 

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The GTR IAT is not a great sensor, it is a solid brass sensor and doesnt protude much into the air stream so it is quite slow to respond.  Many companies sell a replacement fast response sensor that extends further into the airflow which will help.  Here is one example:  http://www.nzefi.com/product/fast-response-iat-sensor-r32-34-skyline-gtr-specific/

The other thing you can do is set up your IAT trim table with TP on one axis, then at small throttle openings and high IAT's, you can add fuel (or remove less).  You will notice our latest GTR base map is set up this way.

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Its a GM sensor but stock location. The actual sensor tip does protrude into the manifold air path.

I read about the IAT trim table in another post from awhile back. If i select this ON, would i start with zero'ing out the entire table and try adding some values in the 0% TPS / higher IAT areas first? 

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5 hours ago, Jeffersonc said:

Its a GM sensor but stock location. The actual sensor tip does protrude into the manifold air path.

I read about the IAT trim table in another post from awhile back. If i select this ON, would i start with zero'ing out the entire table and try adding some values in the 0% TPS / higher IAT areas first? 

Yep, if you are using modelled mode then you will want the IAT trim table to be mostly zeros with just some trim in the top right corner.

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