Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post

nick_d_240sx · 07-11-2019, 08:58 AM

I was going to heavily edit my post above, because it seems I may have went a little to far with the dMapAccel stuff, but I want to leave it as a reference to additional changes that I have been making or will make. Maybe as a 'what not to do'. I was getting really rich bumps when touching the throttle and some pops from the exhaust shifting at low rpm.

Since editing and raising up the dMapAccel wasn't solving my lean midrange, I increased the fuel map in the lower vacuum areas. -10inhg to 2psi and this made quite the difference however it is not perfect. If you compare it to the map above you can see the difference. For those wondering why my positive pressure map is mostly all the same value, I use the boost fuel trim to increase IPW based on boost.

Using the TCD compare under the tools pull down, I compared my map with the canned SR20DET_RT_MANUAL.tcd.
Link to Nismotronic wiki for TCD Compare
Be sure to save your map when making changes or comparing, because I did have it crash/fatal error when trying to compare the fuel map and the software just closes.

My Base IPW ECT settings. I raised this based on John's comment above.

Difference between maps

Map Load Factor Table.

Difference between maps

ECT corrections

Difference between maps

When I went from stock 370cc injectors to 740's I updated the injector size but left the 370 as the base. This allowed me to start the car and start tuning.

Also when making these changes I'm trying to keep transitions smooth by using the, super handy, graphing feature.

I still get the ~12afr idle and I've tried leaning it out and when it goes above ~13.5 is starts missing and popping.
Fuel injector base pressure to low? Stock plugs fouled? **Edit: ordered BKR7EIX plugs** WB reading wrong? I need to look into it, but I'm not convinced it's the tune because it used to idle just fine around ~14afr.

If anyone would like to see the current map and a recent log it is posted up in the link on the first post.

Edit: Is anyone using an aftermarket knock sensor and can you give me any details about why you like it, how you installed it, and how your using it? I keep noticing some weird spikes from the stock sensor around 4700rpm and I'm not sure if it's a knock or just unreliable readings from the stock sensor. I'll do some research as well, just thought I'd throw it out there..

Edit 1-16-20: Car is down for a few upgrades. Thinking the rich idle is from not having the crankcase vent ran to vacuum which will be fixed. More to come in March when I get back at it.

07-11-2019, 08:58 AM	#11
nick_d_240sx Leaky Injector Join Date: Dec 2017 Location: Oregon Age: 42 Posts: 98 Trader Rating: (0)	I was going to heavily edit my post above, because it seems I may have went a little to far with the dMapAccel stuff, but I want to leave it as a reference to additional changes that I have been making or will make. Maybe as a 'what not to do'. I was getting really rich bumps when touching the throttle and some pops from the exhaust shifting at low rpm. Since editing and raising up the dMapAccel wasn't solving my lean midrange, I increased the fuel map in the lower vacuum areas. -10inhg to 2psi and this made quite the difference however it is not perfect. If you compare it to the map above you can see the difference. For those wondering why my positive pressure map is mostly all the same value, I use the boost fuel trim to increase IPW based on boost. Using the TCD compare under the tools pull down, I compared my map with the canned SR20DET_RT_MANUAL.tcd. Link to Nismotronic wiki for TCD Compare Be sure to save your map when making changes or comparing, because I did have it crash/fatal error when trying to compare the fuel map and the software just closes. My Base IPW ECT settings. I raised this based on John's comment above. Difference between maps Map Load Factor Table. Difference between maps ECT corrections Difference between maps When I went from stock 370cc injectors to 740's I updated the injector size but left the 370 as the base. This allowed me to start the car and start tuning. Also when making these changes I'm trying to keep transitions smooth by using the, super handy, graphing feature. I still get the ~12afr idle and I've tried leaning it out and when it goes above ~13.5 is starts missing and popping. Fuel injector base pressure to low? Stock plugs fouled? Edit: ordered BKR7EIX plugs WB reading wrong? I need to look into it, but I'm not convinced it's the tune because it used to idle just fine around ~14afr. If anyone would like to see the current map and a recent log it is posted up in the link on the first post. Edit: Is anyone using an aftermarket knock sensor and can you give me any details about why you like it, how you installed it, and how your using it? I keep noticing some weird spikes from the stock sensor around 4700rpm and I'm not sure if it's a knock or just unreliable readings from the stock sensor. I'll do some research as well, just thought I'd throw it out there.. Edit 1-16-20: Car is down for a few upgrades. Thinking the rich idle is from not having the crankcase vent ran to vacuum which will be fixed. More to come in March when I get back at it. __________________ S13 Last edited by nick_d_240sx; 01-16-2020 at 11:02 PM..