What's the lowest hrz signal the ecu can take in? - 3000GT/Stealth International Message Center

Overboosted · 10-02-2008, 04:05 PM

I can't get my logger to read anything lower than 25hrz, is this normal?

The reason why I ask is that my idle is rich if its under 900 rpm and there seems to be nothing I can do to fix it. I can remove as much fuel as I want on my maft-pro and I can see that the pro is sending a lower signal every time I do but my idle doesent change and neither does the hrz displayed on my logger.

3000GT MR · 10-02-2008, 04:18 PM

i cant answer your Hz question but are you using PT tracking at idle? if you are disconnect o2s and reset your ecu.. if this is your case your o2s are fighting PT tracking and your not making any headwind. some people go as far as fixing the low end of the VE table

Overboosted · 10-02-2008, 04:23 PM

My o2's are unplugged and since fixing the low end of the ve table would do the same as the user tune (lowering the hrz sent to the ecu) that wouldent change anything.

3000GT MR · 10-02-2008, 04:39 PM

i dont know then ask rouge art hes been real helpful in these situations. i think 40ish is stock for Hz right

Overboosted · 10-02-2008, 04:43 PM

Maybe I will post on the maft thread too.

keithmac · 10-02-2008, 04:58 PM

It`s between 22 to 25, the ecu will assume faul mode and ignore it. Only way to trim more out at this point is to let the Mitsi ecu into closed loop, it will then trim quite a bit of fuel until you hit stoich.

I can`t pull enough fuel with the MAS and 450cc injectors.., proobably all the people with bigger injectors on here suffer idle in the 13:1 region or worse?.

Overboosted · 10-02-2008, 05:05 PM

That makes sence. My idle can hit as low as 12:1 sometimes a bit into the 11's. I just hate the idea of fouling up my plugs for 1-2 minutes everytime I shut down the car.

If only there was a way to trick the ecu into closed loop while not changing trims.

edit: or maybe let the ecu into closed loop mode at idle and then somehow stop the o2 feedback as soon at the tps changes or something.

Rogue_Ant · 10-03-2008, 11:35 AM

Overboosted - I replied in the T-Pro thread.

keithmac - You could swap an EVO/3G Eclipse MAF... it reads about ~20-25% lower. Should bring your AFR in enough that the trims can take over (since your injectors are ~25% larger the two cancel eachother out). *edit - didn't see that you had an EM - nevermind about swapping MAF sensors*

-Rogue

donniekak · 10-16-2008, 09:59 PM

I had to raise my idle rpm to get my nb's to dither at idle.

cbehnken · 10-17-2008, 01:00 AM

yeah, especially the evo 560 injectors do this.

I can pull my safc down to -50% at idle and it makes no difference.

doesn't bother me though...

10-02-2008, 04:05 PM	#1 (permalink)
Overboosted Dont f#@k with me I own a Join Date: Jul 2007 Location: Winnipeg Drives: 1991 Stealth TT AWD Trader Rating: (5)	What's the lowest hrz signal the ecu can take in? I can't get my logger to read anything lower than 25hrz, is this normal? The reason why I ask is that my idle is rich if its under 900 rpm and there seems to be nothing I can do to fix it. I can remove as much fuel as I want on my maft-pro and I can see that the pro is sending a lower signal every time I do but my idle doesent change and neither does the hrz displayed on my logger. __________________

10-02-2008, 04:18 PM	#2 (permalink)
3000GT MR Verified Seller Join Date: Jul 2007 Location: stoughton Drives: with MR gears Trader Rating: (6)	Re: What's the lowest hrz signal the ecu can take in? i cant answer your Hz question but are you using PT tracking at idle? if you are disconnect o2s and reset your ecu.. if this is your case your o2s are fighting PT tracking and your not making any headwind. some people go as far as fixing the low end of the VE table __________________ 94 VR4 99 conversion with 6K HIDs and PIAA fogs, 17G/15G combo, FMIC, DN downpipe, 560cc, walbro 255lph hotwired, MR gears, RPS 6-puck clutch, fidanza flywheel, hybrid logger, dejon preturbo, MAFT pro. K&N and custon carbon fiber heat sheild, HKS ssq, blitz turbo timer, 18" TSW kyalamis wraped in proxy 4's, polished Y-pipe, polished strut bar,solid engine mounts, seattle short throw, vac line reduction, misc REAL carbon fiber trim and misc gauges..ect

10-02-2008, 04:23 PM	#3 (permalink)
Overboosted Dont f#@k with me I own a Join Date: Jul 2007 Location: Winnipeg Drives: 1991 Stealth TT AWD Trader Rating: (5)	Re: What's the lowest hrz signal the ecu can take in? My o2's are unplugged and since fixing the low end of the ve table would do the same as the user tune (lowering the hrz sent to the ecu) that wouldent change anything.

10-02-2008, 04:39 PM	#4 (permalink)
3000GT MR Verified Seller Join Date: Jul 2007 Location: stoughton Drives: with MR gears Trader Rating: (6)	Re: What's the lowest hrz signal the ecu can take in? i dont know then ask rouge art hes been real helpful in these situations. i think 40ish is stock for Hz right

10-02-2008, 04:43 PM	#5 (permalink)
Overboosted Dont f#@k with me I own a Join Date: Jul 2007 Location: Winnipeg Drives: 1991 Stealth TT AWD Trader Rating: (5)	Re: What's the lowest hrz signal the ecu can take in? Maybe I will post on the maft thread too.

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10-02-2008, 04:58 PM	#6 (permalink)
keithmac Forum Member Join Date: Sep 2006 Location: YORK / UK Trader Rating: (2)	Re: What's the lowest hrz signal the ecu can take in? It`s between 22 to 25, the ecu will assume faul mode and ignore it. Only way to trim more out at this point is to let the Mitsi ecu into closed loop, it will then trim quite a bit of fuel until you hit stoich. I can`t pull enough fuel with the MAS and 450cc injectors.., proobably all the people with bigger injectors on here suffer idle in the 13:1 region or worse?. __________________ JDM GTO TT, Emanage Blue - 450`s Hotwired Walbro - K&N - Blitz SSBC Port Methanol Injection - E85 - 12.4@115

10-02-2008, 05:05 PM	#7 (permalink)
Overboosted Dont f#@k with me I own a Join Date: Jul 2007 Location: Winnipeg Drives: 1991 Stealth TT AWD Trader Rating: (5)	Re: What's the lowest hrz signal the ecu can take in? That makes sence. My idle can hit as low as 12:1 sometimes a bit into the 11's. I just hate the idea of fouling up my plugs for 1-2 minutes everytime I shut down the car. If only there was a way to trick the ecu into closed loop while not changing trims. edit: or maybe let the ecu into closed loop mode at idle and then somehow stop the o2 feedback as soon at the tps changes or something. Last edited by Overboosted : 10-02-2008 at 05:09 PM.

10-03-2008, 11:35 AM	#8 (permalink)
Rogue_Ant Background Guy Join Date: Aug 2006 Drives: '86 Porsche 944 Trader Rating: (0)	Re: What's the lowest hrz signal the ecu can take in? Overboosted - I replied in the T-Pro thread. keithmac - You could swap an EVO/3G Eclipse MAF... it reads about ~20-25% lower. Should bring your AFR in enough that the trims can take over (since your injectors are ~25% larger the two cancel eachother out). edit - didn't see that you had an EM - nevermind about swapping MAF sensors -Rogue __________________ '86 944 Turbo (951) E-85 Fuel Convert Powerhaus K27DR Turbo MAF Translator Pro - MAP Conversion! With Knock Monitoring! Motronic Enhanements Custom Chip By Hally! Old Dyno Corrected: 390 RWHP, 417 RWTQ @ +5200ft See my build-up here! '02 GSX-R 750 Stock w/ Yoshi slip-on

10-16-2008, 09:59 PM	#9 (permalink)
donniekak Forum user Join Date: Feb 2008 Location: surprise az Drives: 92rt/tt Trader Rating: (5)	Re: What's the lowest hrz signal the ecu can take in? I had to raise my idle rpm to get my nb's to dither at idle.

10-17-2008, 01:00 AM	#10 (permalink)
cbehnken Forest Gump Join Date: Nov 2004 Location: Cape Girardeau Mo Drives: 1992 Stealth TT Trader Rating: (45)	Re: What's the lowest hrz signal the ecu can take in? yeah, especially the evo 560 injectors do this. I can pull my safc down to -50% at idle and it makes no difference. doesn't bother me though... __________________ Power: DSM 13G/DR650 Combo, EVO 560cc injectors, SAFC I, K&N, Ebay Downpipe, ATR Dual Catback, no cats, DN Y-Pipe, HKS SSQV, HKS EVC 5 at 14.5PSI, Walbro 255 with AN Bulkhead 8.07 @ 85.55 1/8th mile 1.84 60FT Suspension: KYB GR-2 - Tein S-Techs, Crossdrilled/slotted rotors, AWS Delete Drivetrain: RPS Street Max, M.W. 300m O/S, Seattle F&R Poly Mounts Etc: Roller Bearing Short Shifter Smokinvr-4 Corner box, 10" Rockford Fosgate Punch sub, Eclipse Headunit Leatherseats.com Charcoal/Dove Grey Interior, 99 front end/lights/wing/sideskirts/doorcaps Maintenance New VSS, all 60K stuff, new 1st,2nd, 3rd syncro, trans seals, oil pump, rod and main bearings. Mobile 1 10w40, Redline MTL in trans, 85w90 Coastal GL5 in transfer case and rear