Rpm drops to 650 rpm before recovering 1,000 rpm
Dipping Below Target Idle on Lift Off
Thanks
Adjusted TPS 0.51v to 5.00v and done the procedure for setting idle. IAC Duty cycle is set to midway between Normal and Increase. I also set (1) the overrun fuel cutoff (tps) delay to 0 msecs (2) and overrun fuel cutoff (map) to 8 kPa for 500rpm and 2000rpm (3) increased timing in the idle portion of the ignition tables (4) and matched the idle speed in the idle versus coolant tempreture. it seems better, but it still happens. By the way I am using Toda C2 cams, so my idle is set at 1,000 rpm. Should I switch closed loop on or off when adjusting the IAC Duty cycle? Would using different rpm breakpoints in the overrun fuel cutoff (map) help?
Adjusted TPS 0.51v to 5.00v and done the procedure for setting idle. IAC Duty cycle is set to midway between Normal and Increase. I also set (1) the overrun fuel cutoff (tps) delay to 0 msecs (2) and overrun fuel cutoff (map) to 8 kPa for 500rpm and 2000rpm (3) increased timing in the idle portion of the ignition tables (4) and matched the idle speed in the idle versus coolant tempreture. it seems better, but it still happens. By the way I am using Toda C2 cams, so my idle is set at 1,000 rpm. Should I switch closed loop on or off when adjusting the IAC Duty cycle? Would using different rpm breakpoints in the overrun fuel cutoff (map) help?
Last edited by Johnny_9 on Fri Aug 13, 2010 6:02 am, edited 2 times in total.
Re: Dipping Below Target Idle on Lift Off
Johnny, take a screen shot of your low fuel MAP and post it. I'll be glad to help. Problem is your tune. Fixed this many times.
Low Fuel Map
- Attachments
-
- 01 skunk2 tb 30 jul 2010.skl
- low fuel map
- (30.87 KiB) Downloaded 182 times
Last edited by Johnny_9 on Mon Aug 23, 2010 4:17 am, edited 1 time in total.
Ok Im done. notice a couple things that I made changes to. Didn't make any changes to the main parts of your map, just the Idle section in Parameter and "below" idle section of the low cam map. I went off of the 1000 rpm idle that you set in the Parameters. Just try this and see how it works out.
- Attachments
-
- 01 skunk2 tb 30 jul 2010 Johnny.skl
- (34.73 KiB) Downloaded 200 times
I added fuel below your idle as to not change the AFR where your car idles at since you said that you wanted you car to idle at 1000. But what I did was as you're slowing down and the rpms drop hard, the injectors will stay open wider in the area where the engine tries to recover after rpms drop suddenly.
Idle - RPM vs Engine Coolant Tempreture
Uploaded with ImageShack.us[/img]
I was interested in setting "Rpm (moving) vs. Engine Coolant Temp" higher at 1,300 r.p.m. versus 1,000 rpm (stationary). Totally missed that.
I'd like to hear in your experience how much that setting helps in stopping rpm dipping and then recovering to target rpm as you slow down and let off the gas.
Thanks for your help. I will play around with that and the IACV duty.
First off, the tune you gave me the Water Temp Numbers are different than above. -40 67 87 106 141 177 302 are the numbers in the tune you gave me.
To answer your question. The reason its needed is because of the loads that put on the engine while slowing down in neutral for instance braking, brake lights, power steering, Alternator etc.. Everything is putting a load in the engine so it's necessary to give the engine some rpm so it doesnt die from the load. Now, you want your idle at 1000rpm without dropping below that when slowing down that's why I gave it 1300 rpm in the 141 and 177 column (moving). When the vehicle comes to rest, it should return to your Stationary idle. 1500 in the 302 column is for overheating situations. As for your IACV setting. It looks like it's in the right spot. Mine and the others I've tune is set 1 notch back or one notch above the middle.
These settings help alot along with keeping those injectors open below your target Rpm so that the engine does not stall.
To answer your question. The reason its needed is because of the loads that put on the engine while slowing down in neutral for instance braking, brake lights, power steering, Alternator etc.. Everything is putting a load in the engine so it's necessary to give the engine some rpm so it doesnt die from the load. Now, you want your idle at 1000rpm without dropping below that when slowing down that's why I gave it 1300 rpm in the 141 and 177 column (moving). When the vehicle comes to rest, it should return to your Stationary idle. 1500 in the 302 column is for overheating situations. As for your IACV setting. It looks like it's in the right spot. Mine and the others I've tune is set 1 notch back or one notch above the middle.
These settings help alot along with keeping those injectors open below your target Rpm so that the engine does not stall.
TPS Scale (min) - Can it accept a NEGATIVE Value?
Cancel
Last edited by Johnny_9 on Sat Sep 18, 2010 5:55 am, edited 2 times in total.