I have a completely stock 97 GSR running Neptune RTP. I been having an issues where the car bogs in and out under decel, around 3k to 4k rpm. I datalogged it today and I noticed the fuel cut was turning on and off at the same time I feel the issue. I believe I have the Fuel Cut parameters out of proper adjustment. I put in my stock obd2 P72 in and the problem goes away.

I created a stock P72 base map from the Neptune Base Map menu. I'm not sure what the value should be under the Parameters: Extras: Fuel Cut menu. I figured these should be set to regular or normal operation of a stock P72 when creating a Stock P72 Base Map.(maybe I changed it though)

settings currently

below load: 213
below TPS: 5%
min rpm : 1900rpm
min mph : 0mph
fuel cut delay: +---------------*---------+

 

If you're bone stock then running the stock ecu would be more ideal.

Besides that you'll just have to play with it to see where you car likes it the most.


Look here for better responses

http://www.hrtuning.com/forum/viewforum.php?f=14

 

Trying to learning a lil more with my stock GSR before I build a b20vtec.

 

Make sure your closed TPS voltage is set correctly and you're at 0% with throttle closed then perhaps lower the TPS % setting so it doesn't kick in if you're cruising at less than 5%. You can also see what your MAP is when you're off the throttle and adjust the MAP setting to be closer to that. If you're going in and out of fuel cut one of those parameters is not being met.

 

It only does it off throttle. I will check my TPS value tomorrow.

 

when you say it only does it off throttle thats how you have it set up. your fuel cut delay time is way to long try 2/3's less and read the rtp forum that is where i found how to fix mine.

 

Its actually probably the Map value. Try setting it to like 280kpa and set your TPS threshold to 1% and see if that clears it up..

 

Agreed.

You can setup a light on the gauges in NepTune's software so it will light up when Fuel Cut is triggered.

The bets way to make sure the car hits fuel cut is to just rev the motor to 4000 RPM or so and just let off the throttle and let the RPMs drop just under 2000, while this is happening take a log and make sure the Fuel Cut light stays lit the whole time.

If not, it is likely your min map setting which is causing the car to have what is like a fuel cut oscillation, (it will cut fuel then the map reading will go above your min and it will inject fuel, then the map reading will drop below the min and then it will cut fuel, etc.) Basically a noticeable oscillation which is very simple to tune out.

Generally I raise the map setting anywhere from 250mbar to 280mbar on some cars and have the TPS setting around 1-2%.

I almost bet that clears it right up.

 

I checked out my log from last night and noticed MAP was hitting over my min while under fuel cut. Raise min. load and seems gone now.

Thank for your help.

P.S. Should fuel cut be disabled during street tuning?