Supercharger seventh injector versus upgraded six injectors

I've had the Walboro 190 pump installed for almost 5 years with my 7th kit. It's noisy AF when it's hot but it's been like that since day 1. Silent day to day commuting around town, but on a long freeway drive or long off-road trip it will start to howl.

According to Walboro its a characteristic of the pump design and nothing to worry about, though it is annoying. If I'd known back then before I had it installed I would've switched it for something else.

 

thx for all the help @Jon64l . really appreciate the input

 

ive heard that too which is why i'm assuming mine's stock. Is there a different look to yours as compared to stock when you open the door under the rear driver side seat? hopefully i can identify mine some way besides "it doesnt have a sound"

 

mile HIGH means LESS Air

several on here put more fuel to the engine

if U have a way to monitor mid range & WOT.......more fuel might be warranted

Not Likely

until U can substantiate air/fuel ratio BEFORE & After

7th injector UNnecessary

 

which aem pump were you using? I'm trying to find one with similar flow to the Walbro 190 but most im seeing are 340lph+

 

I am using the 340. It is over kill. But I am also turbo and have 440cc injectors.

You could probably get away with a stock pump on the 2.5" low boost pulley.
Maybe consider a twin turbo supra fuel pump if you need the fuel after all. You really just need to get the SC on there with a wide band to see how things are meshing together. Or sell it to me

 

This is true, plus I believe @1997tacomav6 is still running a stock/OEM Denso fuel pump while making 10psi. He's also at higher elevation in CO.

 

ok great news. The previous previous owner who had the SC installed was super nice and dug up the receipts for the install. Huge shout out to that guy.
So apparently a Walbro 190 was installed, but this thing is dead quiet. I've only driven it a few miles here and there so far and it has a full tank, but the previous owner also said he's never heard a noise from it.
I hope someone didn't replace it with a stocker at some other point in its life.

to run an AFR gauge i just need to drill a hole and weld a bung for a wideband o2 sensor right? I'm assuming that doesn't go straight to the gauge, so where does it hook up to?

 

Mine goes through phases it seems like, to be honest I haven't heard a peep from it in months. But then once it does start getting noisy it'll do it for months on end. Give it time lol.

 

Disconnect Battery. Drill a hole for 02 bung in Y pipe before Cat. Weld. Install the sensor supplied with guage. Find a pass thru into the cabin. I used a fuse tap in the cabin fuse panel under steering wheel. Hook it all up and connect Battery.

 

in the mean time, before my AFR gauge comes in, any idea what my long term and short term fuel trims should look like?

just to recap so you guys dont have to look for my other posts:

2.2 pulley (i measured it wrong when i said 2.5, also found the receipt for the 2.2)
URD 7th injector
Walbro 190 (a suspiciously quiet one, but i have the receipts from prev prev owner)
K&N intake thing, goes from stock box location to the throttle body
stock exhaust

No knocking or pinging any any rpm/load range, but a little rough idle (gonna do new plugs and get the injectors cleaned while i do valve cover gasket)

 

The fuel trim thing is hard to answer honestly. Some people claim near zero with the supercharger, stock injectors, etc.

But there’s the thing. In stock N/A form the vacuum hose from the fuel regulator is hooked up BEFORE the throttle body. It never saw vacuum at idle and Toyota tuned the fueling this way.

When you convert to the TRD Supercharger you change the location that the fuel regulator is referenced to at the manifold. So now it’s seeing -21in of Mercury of vacuum where as it didn’t before.

This technically lowers fuel pressure which lowers the amount of fuel supplied per injector pulse at idle. The computer is going to compensate by adding fuel because it’s running lean.

mine have always been high. If I unplug the vacuum hose to the fuel regulator my fuel trims drop like a rock closer to 0.

Anybody else experience this?

 

I don’t know why you would think that we need WOT runs before and after to confirm AFRs when we already know OPEN LOOP does not use the AFR sensor to correct for fueling.

MORE AIR + N/A fuel maps = LEAN

 

2.2 changes things. You are lucky you are in high altitude. I couldn't get my truck to the main road without experiencing ping when I first installed the SC. I quickly pulled timing progressively in the maps and it helped dramatically. I do live in Arizona fwiw.

Lots of good info posted by other folks on here!

As stated, typically you want lower fuel trims. It throws a code around 19 I believe. That's how I found a vacuum leak.

Ultimately each truck and location is different, so do what works for you.

 

hooked up an OBII reader and got some data points. Seems pretty healthy but I haven't found a lot to compare it to (and IDK wtf im talking about )
BTW im in San Diego and not getting any pinging anywhere in the rev/load range

Idle - at idle its really rich (7th injector working when it doesnt need to?)
short term fuel trim 0 to -4.8
long term fuel trim -16.4 pretty steady

Partial Throttle - cruisin around town
short term fuel trim -1 to -5 with occasional spikes to 3
long term fuel trim -4 to -8

Wide Open Throttle - these numbers don't seem to budge
short term fuel trim 0
long term fuel trim 5.5

 

I thought you were in the mile high city for some reason.

Honestly that isn't bad overall. The -16.4 is a little suspect, but the rest seems fine Assuming afr is in check. Cali 93 octane might be treating you well, not to mention cool air year round.

Change the plugs and fuel filter with quality items and enjoy that rig.

 

many think 7th injector necessary................usually Not

definitely Not at idle

the ECM does have some latitude w/o the extra fuel

WOT is 1 zip code the Epa is not concerned about

so little time by the masses spent at WOT

 

You’re running super rich. That’s a bit odd. I’d be looking at the MAF and the fuel injectors.

The 7th injector does not do anything at all until you hit boost. The stock maps retard the timing ~ 1-2 degrees per psi, it enriches CLOSED LOOP fueling to 13.5 in boost and it starts the spray fuel @ 4PSI and 3000RPM. The amount of fuel ramps as the RPMS and boost increase.

Unless the maps are way wonky from being set up improperly I would be trying to find out why my truck is trying to pull so much extra fuel out.

Fuel trims are not used during WOT.

The difference between Open loop and closed loop is that closed loop the AFR sensor is being used to correct AFRs. This is why you’re seeing negative fuel trims. The factory AFR sensor is seeing all this extra fuel and the ECU is cutting the pulse with of the injectors by 10%

during wide open throttle the computer switches OPEN LOOP. The ECU is now ignoring the AFR sensor and only going off of maps set up by Toyota for naturally aspirated air flow. When you add the supercharger the ECU has no way of knowing this. Now that you’re cramming more air in it’s going to run lean with those stock N/A fuel maps. Especially with smaller pulleys.

This is why you should not listen to that other guy on how you should tune your truck. He may have 20+ years of engine building but he doesn’t know how your truck is running, nor does he seem to understand how the 7th even works.


Use your standalone wideband AFR sensor and learn how to open up the R4 software. It’s easier and cheap to open up the R4 software to make sure those Stock maps are set up correctly.

 

no one ‘ needs ‘ WOT

no one needs a SC

no 1 needs ‘ running super rich ‘

Im all wet.................................................not !