Question about vacuum throttle opener to SC

JHRRLD · 01-22-2007, 05:43 PM

Searched didn't find anything

Here's the story:

Couple of week ends ago I installed the TuRD Gen II supercharger and URD fuel kit on my 2000 4wd 4runner. Everything went fine. I was experiencing some mild pinging when I first got everything running. I remember reading that having the Deck plate mod without the proper tune can cause this. I screwed back in my deck plate and that pretty much fixed it until I have the time to properly tune it.

Well tonight I installed a AIRaid modular intake tube. While I was in there I noticed that I didn't hookup any vacuum line to the vacuum throttle opener on the TB. Ran to the auto parts store to pick up some vacuum line to hook it up like the TRD vacuum routing diagram states: vacuum throttle opener to the vacuum port on the backside of the supercharger just behind the TB. I previously had this port wide open (on SC) without any problems. (no codes). So when I have the line installed the engine starts and then stumbles and dies. So I pull it off and start it up and reinstall the vacuum hose while the engine is running and it dies. So I just left the vacuum throttle opener unhooked and put a vacuum cap on the port on the supercharger. Pinging is gone and now I have much more low end torque.

Anyone know why this would be the case? Is it okay to leave the vacuum throttle opener unhooked?

Thanks for any input.

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TRDatVT · 01-22-2007, 06:03 PM

Hook everything up correctly and pull the EFI fuse and relay under the hood in the black fuse box for a night, or just for a few hours... This will reset your fuel trims that have been ruined since your computer has been trying to compensate for the extra air it was "magically" pulling from the open tube (this occured since the leak was behind the MAF sensor). Go ahead and hook the fuse and relay back in and start the truck and let it idle for 2 or 3 minutes or until its nice and steady around 650-750... then drive it and see what happens!

JHRRLD · 01-22-2007, 08:54 PM

Quote:

Originally Posted by TRDatVT

Hook everything up correctly and pull the EFI fuse and relay under the hood in the black fuse box for a night, or just for a few hours... This will reset your fuel trims that have been ruined since your computer has been trying to compensate for the extra air it was "magically" pulling from the open tube (this occured since the leak was behind the MAF sensor). Go ahead and hook the fuse and relay back in and start the truck and let it idle for 2 or 3 minutes or until its nice and steady around 650-750... then drive it and see what happens!

Thanks, before I posted this q I pulled the relay for about 20 minutes, Didn't know there was a fuse too. Got em both pulled now for the night. Will report back in the morning.

MTL_4runner · 01-23-2007, 05:37 AM

Quote:

Originally Posted by JHRRLD

Thanks, before I posted this q I pulled the relay for about 20 minutes, Didn't know there was a fuse too. Got em both pulled now for the night. Will report back in the morning.

Pulling the negative battery terminal is the most complete way to do it, but it will reset your radio stations.

JHRRLD · 01-23-2007, 06:34 AM

That fixed me. Thanks guys...

I understand what was going on now. Additional air coming in not read by the MAF was causing a semi lean condition. After the ECU adjusted to that additional air coming in (after the throttle body mind you) when I cut it off without reseting the ECU it would die because that additional air was no longer there.

mastacox · 01-24-2007, 07:10 AM

You're going to have to adjust your fuel map on the FTC also, use Gadget's U-Tune guide. Do you have Wideband?

JHRRLD · 01-24-2007, 07:48 AM

Quote:

Originally Posted by mastacox

You're going to have to adjust your fuel map on the FTC also, use Gadget's U-Tune guide. Do you have Wideband?

Yep, this weekend. Let the fun begin...

TRDatVT · 01-24-2007, 08:57 AM

Glad that worked out for you... Lay down any dyno numbers?

JHRRLD · 01-24-2007, 09:02 AM

Quote:

Originally Posted by TRDatVT

Glad that worked out for you... Lay down any dyno numbers?

No dyno runs. I'm just going to road tune it for now with no real plans to dyno it.

01-22-2007, 06:03 PM	#2 (permalink)
TRDatVT Registered User Join Date: Jun 2006 Posts: 275	Hook everything up correctly and pull the EFI fuse and relay under the hood in the black fuse box for a night, or just for a few hours... This will reset your fuel trims that have been ruined since your computer has been trying to compensate for the extra air it was "magically" pulling from the open tube (this occured since the leak was behind the MAF sensor). Go ahead and hook the fuse and relay back in and start the truck and let it idle for 2 or 3 minutes or until its nice and steady around 650-750... then drive it and see what happens! __________________ 1999 4 Runner 9.9 sec 1/8 mile on 7 psi and fuel injectors only (NO Alcohol) weak tune! TRD Supercharger, Alcohol Injection, Walbro fuel pump upgrade, Custom 2.5" stainless exhaust, 3" Tundra/LC Coil Lift, 1.5" 4Crawler BL, 305/70/16 Mickey Thompson MTZ's... Next: HID Bi-xenon Conversion, Tundra brake upgrade...

01-23-2007, 06:34 AM	#5 (permalink)
JHRRLD Registered User Join Date: Aug 2006 Location: Tulsa Posts: 138	That fixed me. Thanks guys... I understand what was going on now. Additional air coming in not read by the MAF was causing a semi lean condition. After the ECU adjusted to that additional air coming in (after the throttle body mind you) when I cut it off without reseting the ECU it would die because that additional air was no longer there. __________________ 2000 4WD 4Runner Sport, auto, 5VZ, SC, URD fuel kit, 2.2" pulley, 4" deckplate, Trueflow filter, Airraid mini intake, TRD Exhaust, trans cooler, IPT Valve Body, TrueTrac rear, SS 7.2, 285 75R 16 BFG ATs on PC'd LX450 wheels, JAOS color matched Spoiler, Line-X'd stubbs sliders 07 Kawasaki Brute Force 750i, stock for now

01-24-2007, 07:10 AM	#6 (permalink)
mastacox Contributing Member Join Date: Dec 2003 Location: Los Alamos, NM Posts: 2,652	You're going to have to adjust your fuel map on the FTC also, use Gadget's U-Tune guide. Do you have Wideband? __________________ Brian 1998 4Runner SR5

01-24-2007, 08:57 AM	#8 (permalink)
TRDatVT Registered User Join Date: Jun 2006 Posts: 275	Glad that worked out for you... Lay down any dyno numbers? __________________ 1999 4 Runner 9.9 sec 1/8 mile on 7 psi and fuel injectors only (NO Alcohol) weak tune! TRD Supercharger, Alcohol Injection, Walbro fuel pump upgrade, Custom 2.5" stainless exhaust, 3" Tundra/LC Coil Lift, 1.5" 4Crawler BL, 305/70/16 Mickey Thompson MTZ's... Next: HID Bi-xenon Conversion, Tundra brake upgrade...

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