Lean Misfires at 2700-2800 rpm - Page 59 - 3000GT/Stealth International Message Center

badass3000 · 12-14-2007, 09:51 PM

yeah, my cars been back together for a while, driven it around the block a few times, but the tune is soo far off its a bear to drive. I cant tell if I made any headway.

do you plan on checking your valves? Im not sure if I can check them w/o removing ALL of them. the oil on them might make the dark enamel hard to see. Its supposed to be on the top.

DoctorDex · 12-15-2007, 12:39 AM

Quote:

Originally Posted by badass3000

Im not sure if I can check them w/o removing ALL of them. the oil on them might make the dark enamel hard to see. Its supposed to be on the top.

How big of an area does the dark enamel cover? Is it just on the very top, like in the pics? Is there a way to tell by looking at the "twists"?

When I take my car out of storage in spring, I'm going to first double check that my timing belt hasn't jumped a tooth or something and I'm going to pull the valve covers off and check the clearance of the cams lobes (to make sure they are all worn equally). Then I'm going to check each rocker piece, to make sure the needle bearings inside don't have a flat spot (this tends to happen with piston-valve strikes). My motor was rebuilt ~ 20000 miles ago because of a bent valve and I don't think they changed the rocker piece, so this could be causing uneven wear and/or ticking. Lastly, if I can't find anything wrong, I'll pull each lifter out, test them and then examine the valve springs. Its too bad I have to wait until spring... my car has been in storage now for ~ 2 months and I almost feel like working on it again.

StealthCRF · 12-15-2007, 02:15 PM

I know its a long shot, but I really want to see a video of spark plug ingestion

10CentGT · 12-17-2007, 10:59 PM

Why is that many people are having this problem? I am having this problem my self too. At low RPM and higher gears, the car is misfiring and hesitating like crazy. But after like 3500 RPM, it's fine. Has any body been able to figure out this problem? If there's a boost leak, will it cause the misfiring and hesitating through out the RPM band or just at certain RPM bands? I have check every thing and at first I was thinking it might have being my emanage ultimate but I unplug it but the problem was till there. But the funny thing about it is the previous night I drove the car and it was just find. The problem just magically disappeared and now it came back as quickly as it disappeared.

DoctorDex · 12-18-2007, 11:29 AM

Quote:

Originally Posted by 10CentGT

The problem just magically disappeared and now it came back as quickly as it disappeared.

The missing problem that I have seems to get a bit better when the car is warm. Does that account for the difference?

UCSB VR4 · 12-18-2007, 12:07 PM

Just as an FYI, I'll be ditching the ARC II and switching to MAFT-PRO w/ speed density & wideband in the next few weeks.

I'll report the resulting affects on this problem.

Thanks,
Jeff

10CentGT · 12-18-2007, 11:25 PM

No, whether warm or cold, it's still misfiring? But I took out the spark plug and I found out that 5 of the plugs were fine but one of them was really dark with a clear sign of that cylinder running really rich. Could it be that that injector on that cylinder is bad and what will it be doing?

ProwlerGT · 12-19-2007, 03:11 AM

Where tha hell we at with this problem?

I've been away dealing with my life's drama drama.

DoctorDex · 12-19-2007, 10:30 AM

Quote:

Originally Posted by 10CentGT

No, whether warm or cold, it's still misfiring? But I took out the spark plug and I found out that 5 of the plugs were fine but one of them was really dark with a clear sign of that cylinder running really rich. Could it be that that injector on that cylinder is bad and what will it be doing?

You could try swapping in a new injector...

turbomaniac · 12-20-2007, 02:35 PM

I used to have that problem, for like a year in fact. I thought it was pump, injectors, or even turbos, then come to find out, it was my TPS sensor, so try that? that's what worked for me.

12-14-2007, 09:51 PM	#581 (permalink)
badass3000 Wanted: Traction Problems Join Date: Nov 2002 Location: Jacksonville, Fl Drives: 18 Y.O. "badass" VR4 Trader Rating: (21)	Re: Lean Misfires at 2700-2800 rpm yeah, my cars been back together for a while, driven it around the block a few times, but the tune is soo far off its a bear to drive. I cant tell if I made any headway. do you plan on checking your valves? Im not sure if I can check them w/o removing ALL of them. the oil on them might make the dark enamel hard to see. Its supposed to be on the top. __________________ ++++++++++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

12-15-2007, 02:15 PM	#583 (permalink)
StealthCRF Gixxer Fixer Join Date: Feb 2002 Location: Dallas/Fort Worth Drives: on empty Trader Rating: (4)	Re: Lean Misfires at 2700-2800 rpm I know its a long shot, but I really want to see a video of spark plug ingestion __________________ 92 Stealth RT/TT Best time: 13.2 @105

12-17-2007, 10:59 PM	#584 (permalink)
10CentGT I ♥ JDM Hoes Too! Join Date: Aug 2007 Trader Rating: (3)	Re: Lean Misfires at 2700-2800 rpm Why is that many people are having this problem? I am having this problem my self too. At low RPM and higher gears, the car is misfiring and hesitating like crazy. But after like 3500 RPM, it's fine. Has any body been able to figure out this problem? If there's a boost leak, will it cause the misfiring and hesitating through out the RPM band or just at certain RPM bands? I have check every thing and at first I was thinking it might have being my emanage ultimate but I unplug it but the problem was till there. But the funny thing about it is the previous night I drove the car and it was just find. The problem just magically disappeared and now it came back as quickly as it disappeared.

12-18-2007, 12:07 PM	#586 (permalink)
UCSB VR4 Forum Member Join Date: Jan 2003 Location: San Jose, CA Drives: 1992 3000GT VR4 Trader Rating: (1)	Re: Lean Misfires at 2700-2800 rpm Just as an FYI, I'll be ditching the ARC II and switching to MAFT-PRO w/ speed density & wideband in the next few weeks. I'll report the resulting affects on this problem. Thanks, Jeff __________________ 1992 RED 3000gt VR4: Air: DR 650s, DSM SMICs w/ 1 3/4" piping, hard pipe kit upgrade & 2 pre-turbo (no-maf) pipes w/ filters, GReddy Type-S BOV (open loop). Fuel: MAFT-PRO v5.03 (SD mode w/ Electronic Boost & Timing Control, GM 3 BAR MAP Sensor, GM IAT Sensor, & Innovate LC-1 wideband O2), Supra fuel pump (hotwired), 550cc PTE injectors @ 45 base psi. Ignition: Magnecore KV85-R100 spark plug wires, Denso iridium IK27 spark plugs gapped @ .034", Odyssey PC925 battery. Engine: .03" Overbore, 2nd-gen Lifters, polished heads. Exhaust: Gutted precats, ATR 3" downpipe, 3'' CAT, ATR 3" catback. Drivetrain: RPS 6-puck disk, RPS lightweight flywheel, 3sx lightweight drive pulley, polyurethane motor mounts, stillen drilled and slotted rotors, 18x9.5 5Zigen FN01RC rims, BF-Goodrich KDW-2 tires, Cusco rear strut bar. Miscellaneous: Corbeau seats, short throw shifter, presidential alarm system, 8 inch bazooka tube, kenwood double-din deck, 300lbs of miscellaneous weight reductions... "who's your daddy?" license plate Future Mods: 1 Piece PST CFDS

12-18-2007, 11:25 PM	#587 (permalink)
10CentGT I ♥ JDM Hoes Too! Join Date: Aug 2007 Trader Rating: (3)	Re: Lean Misfires at 2700-2800 rpm No, whether warm or cold, it's still misfiring? But I took out the spark plug and I found out that 5 of the plugs were fine but one of them was really dark with a clear sign of that cylinder running really rich. Could it be that that injector on that cylinder is bad and what will it be doing?

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12-20-2007, 02:35 PM	#590 (permalink)
turbomaniac Forum Member Join Date: Feb 2006 Location: Corpus Christi, Tx Drives: 91/99 3000gt vr4 Trader Rating: (0)	Re: Lean Misfires at 2700-2800 rpm I used to have that problem, for like a year in fact. I thought it was pump, injectors, or even turbos, then come to find out, it was my TPS sensor, so try that? that's what worked for me.