Lean Misfires at 2700-2800 rpm - Page 27 - 3000GT/Stealth International Message Center

DoctorDex · 04-18-2007, 05:59 PM

I'll have to look this up, but I believe the 3 ECU "chassis ground" pins connect to different grounding points in the car??

Edit: Looked this up and here's what I found:
Pins 26 & 71 - Both ground the ECU to ground point #2, which corresponds to the point beside the wiper motor on the firewall.
Pin 13 - Is the ground for the CAS. However, I can't tell from the manual where on the car it is grounded to.

I think I'll wire up all my accessories to wires coming off of Pins 26 or 71.

badass3000 · 04-21-2007, 06:54 PM

pins 13 and 26 are connected right off the ECU then to ground point #2 along with pin 71.

badass3000 · 04-23-2007, 02:59 PM

any thing new?
did you try those other sparkplugs wires?
I still think it has something to do with my jumpy rpm that I logged.
heres what I mean...

DoctorDex · 04-23-2007, 03:43 PM

Nothing new except my Supra pump died the other day. Maybe that's what was causing my car to die suddenly without explanation. Checked it with both the check connector and directly with the battery and she's dead.

As far as other things go, I found another ECU, so hopefully it'll cure my problems. Once I get it and a new fuel pump installed I'll post the results. Looking forward to getting this meth. kit installed too.

badass3000 · 04-23-2007, 03:46 PM

haha, did you copy any of my(Trevors) meth kit?
Ill give you some pics and details if you need them.

regulator213 · 04-23-2007, 03:58 PM

wow i have the same problems. except mine went away after i shut my car off. it all orignated when i sprayed mass airflow sensor cleaner on my mass airflow sensor. on the way home it started stuttering at 27-2800rpm. then it totally died. my mass airflow sensor is shot. does your car idle good? when at idle, give the mass airflow sensor a good smack with the butt of a screwdriver and see if it doesn't change the idle/kill the car. if it does then it's pry time for a new mass airflow sensor....not sure if this is any help but after 27 pages, any help is pry appreciated.

DoctorDex · 04-23-2007, 04:02 PM

A little bit yeah.

I bought the stage 2d kit with the 220psi upgrade. I was just going to go with 1 nozzle, but I figured with 2 I can customize how much meth is going in a little better, so I'm ordering the dual nozzle upgrade as we speak. As far as a tank is concerned, I found a used 3.5 L euro headlight washer tanks (with the stock fluid level indicator) to fit in the front bumper. Still waiting on it to show before I can tackle this project.

Currently researching the idea of using the AUX wire on the MAFTranslator.

DoctorDex · 04-23-2007, 04:04 PM

Quote:

Originally Posted by regulator213

wow i have the same problems. except mine went away after i shut my car off. it all orignated when i sprayed mass airflow sensor cleaner on my mass airflow sensor. on the way home it started stuttering at 27-2800rpm. then it totally died. my mass airflow sensor is shot. does your car idle good? when at idle, give the mass airflow sensor a good smack with the butt of a screwdriver and see if it doesn't change the idle/kill the car. if it does then it's pry time for a new mass airflow sensor....not sure if this is any help but after 27 pages, any help is pry appreciated.

I no longer have the stock MAF, I have a GM MAF. No idle problems, just misfires in the 2600 - 3000 rpm range, the worst part being 2700-2800 rpm. Also noticed rpm oscillate under hard acceleration (similar to badass3000's pics).

regulator213 · 04-23-2007, 04:22 PM

yeah, my car idles perfect. it was just when it would hit 2800 it would lose most power, then gain it back at 3 with what seems to be full power. try hitting the sensor with the butt of a screwdriver or something at idle. it is worth a shot??? because it seems like we have SIMILAR problems.

DoctorDex · 04-23-2007, 04:56 PM

Getting really off topic here, but maybe TurboBob can help. Bob how many volts are needed to trigger the "AUX" wire of the MAFT? I've been looking at using a relay, wired into the electronic injection solenoid of the snow kit, to trigger the AUX wire. Is 12 V from the battery too much for the AUX wire?

04-18-2007, 05:59 PM	#261 (permalink)
DoctorDex Forum Member Join Date: Jul 2005 Location: Edmonton, AB Drives: '91 VR4 - RIP Trader Rating: (13)	Re: Lean Misfires at 2700-2800 rpm I'll have to look this up, but I believe the 3 ECU "chassis ground" pins connect to different grounding points in the car?? Edit: Looked this up and here's what I found: Pins 26 & 71 - Both ground the ECU to ground point #2, which corresponds to the point beside the wiper motor on the firewall. Pin 13 - Is the ground for the CAS. However, I can't tell from the manual where on the car it is grounded to. I think I'll wire up all my accessories to wires coming off of Pins 26 or 71. __________________ '91 VR4 - Modlist: DR650R turbos, Snow stage 2D alky kit, DSM SMICs, blowthrough ported LT1 MAS, Dejon Tool intakes & y-pipe, Blitz DSBC Spec R, HKS SSQV BOV, PTE 580cc injectors, Dual feed fuel system with Aeromotive FPR & filter, Hotwired Supra pump, HKS DLI, MSD Wires, Apex'i S-AFC II, MAFTranslator, Turbobob ECU, Scanmaster III, LC-1 WBO2, ESP downpipe, Vac/EGR delete, Gutted precats and test pipe, Maximal solid mounts, 300m 18 spline output shaft, Centerforce Dual Friction clutch, RPS flywheel, GC coilover conversions with helper springs, Powerslot slotted rotors, Goodridge SS brake lines, Hawk pads (front), Stillen metal matrix pads (rear) Last edited by DoctorDex : 04-18-2007 at 08:19 PM.

04-21-2007, 06:54 PM	#262 (permalink)
badass3000 Wanted: Traction Problems Join Date: Nov 2002 Location: Jacksonville, Fl Drives: 18 Y.O. "badass" VR4 Trader Rating: (20)	Re: Lean Misfires at 2700-2800 rpm pins 13 and 26 are connected right off the ECU then to ground point #2 along with pin 71. __________________ ++++++++++JUNE 2007 RIDE OF THE MONTH+++++++++++ Slideshow1..........Slideshow2..........My Photobucket..........My ImageStation.........MOD LIST Questions about the silver car?.....Rear message board info.....Turbo oil cap info.....nicest ass

04-23-2007, 02:59 PM	#263 (permalink)
badass3000 Wanted: Traction Problems Join Date: Nov 2002 Location: Jacksonville, Fl Drives: 18 Y.O. "badass" VR4 Trader Rating: (20)	Re: Lean Misfires at 2700-2800 rpm any thing new? did you try those other sparkplugs wires? I still think it has something to do with my jumpy rpm that I logged. heres what I mean...

04-23-2007, 03:43 PM	#264 (permalink)
DoctorDex Forum Member Join Date: Jul 2005 Location: Edmonton, AB Drives: '91 VR4 - RIP Trader Rating: (13)	Re: Lean Misfires at 2700-2800 rpm Nothing new except my Supra pump died the other day. Maybe that's what was causing my car to die suddenly without explanation. Checked it with both the check connector and directly with the battery and she's dead. As far as other things go, I found another ECU, so hopefully it'll cure my problems. Once I get it and a new fuel pump installed I'll post the results. Looking forward to getting this meth. kit installed too.

04-23-2007, 03:46 PM	#265 (permalink)
badass3000 Wanted: Traction Problems Join Date: Nov 2002 Location: Jacksonville, Fl Drives: 18 Y.O. "badass" VR4 Trader Rating: (20)	Re: Lean Misfires at 2700-2800 rpm haha, did you copy any of my(Trevors) meth kit? Ill give you some pics and details if you need them.

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04-23-2007, 03:58 PM	#266 (permalink)
regulator213 Forum Member Join Date: Oct 2006 Location: kansas Drives: 97 3000gt Trader Rating: (1)	Re: Lean Misfires at 2700-2800 rpm wow i have the same problems. except mine went away after i shut my car off. it all orignated when i sprayed mass airflow sensor cleaner on my mass airflow sensor. on the way home it started stuttering at 27-2800rpm. then it totally died. my mass airflow sensor is shot. does your car idle good? when at idle, give the mass airflow sensor a good smack with the butt of a screwdriver and see if it doesn't change the idle/kill the car. if it does then it's pry time for a new mass airflow sensor....not sure if this is any help but after 27 pages, any help is pry appreciated.

04-23-2007, 04:02 PM	#267 (permalink)
DoctorDex Forum Member Join Date: Jul 2005 Location: Edmonton, AB Drives: '91 VR4 - RIP Trader Rating: (13)	Re: Lean Misfires at 2700-2800 rpm A little bit yeah. I bought the stage 2d kit with the 220psi upgrade. I was just going to go with 1 nozzle, but I figured with 2 I can customize how much meth is going in a little better, so I'm ordering the dual nozzle upgrade as we speak. As far as a tank is concerned, I found a used 3.5 L euro headlight washer tanks (with the stock fluid level indicator) to fit in the front bumper. Still waiting on it to show before I can tackle this project. Currently researching the idea of using the AUX wire on the MAFTranslator.

04-23-2007, 04:22 PM	#269 (permalink)
regulator213 Forum Member Join Date: Oct 2006 Location: kansas Drives: 97 3000gt Trader Rating: (1)	Re: Lean Misfires at 2700-2800 rpm yeah, my car idles perfect. it was just when it would hit 2800 it would lose most power, then gain it back at 3 with what seems to be full power. try hitting the sensor with the butt of a screwdriver or something at idle. it is worth a shot??? because it seems like we have SIMILAR problems.

04-23-2007, 04:56 PM	#270 (permalink)
DoctorDex Forum Member Join Date: Jul 2005 Location: Edmonton, AB Drives: '91 VR4 - RIP Trader Rating: (13)	Re: Lean Misfires at 2700-2800 rpm Getting really off topic here, but maybe TurboBob can help. Bob how many volts are needed to trigger the "AUX" wire of the MAFT? I've been looking at using a relay, wired into the electronic injection solenoid of the snow kit, to trigger the AUX wire. Is 12 V from the battery too much for the AUX wire?