The 3.4L TRD Supercharger Thread

Hey guys I just hit 300k and need to replace a bad injector. I have 1st gen supercharger with air box mod and TRD exhaust - should I mess with trying to source Supra injectors (no plans on further mods) or just get fresh stock injectors (might as well replace them all if I have to tear apart the rail and get new seals)?

Yes if you are ok with installing a larger fuel pump. It'll start to lose fuel pressure at WOT without it. Still more fuel then you are getting right now though, it'll just be near impossible to tune if you decide to go that route. I've been running mine for about 7 years. Get the blue top Supra injectors that have Air Assist like ours do, it'll idle better.

In short, yes it's worth it. Better with a 190LPH - 250LPH fuel pump but not critical.
 
So I’m going through my parts and I’m missing the one check valve that goes under the throttle body. Does anyone know where to buy one?


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Thanks guys! I'm actually going to go with these 295cc injectors from MotorWest: Set of 6 295cc 28lb Upgrade Fuel Injectors for all 3.4L 1996-2004 Toyota Engines HP5194 | MotorWest Performance

I think they will give it just enough extra ooomph without having to worry too much about the ecu. Also, I wasn't having a lot of luck sourcing REAL Supra injectors without paying through the nose.


That’s insane I paid $160 for my injectors prices have gone up I guess but I got mine and have gotten multiple sets for other friends from eBay. I’ll find the link and post it if you’re interested.
 
FWIW, I'm running the lime green top 315cc out of the 7MGE engine with no issue. I snagged them at a junkyard out of a Toyota Cressida (same motor as MKIII Supra) and sent them off to be professionally cleaned. They are the non-air assist type. I ran those injectors while naturally aspirated first, and didn't have any issues. Not having the air assist port blocked off was creating a bit of a vacuum leak, so I blocked off the air assist hose at the y-fitting when I installed the turbo and it still runs great. I think air assist is over rated IMO.
 
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FWIW, I'm running the lime green top 315cc out of the 7MGE engine with no issue. I snagged them at a junkyard out of a Toyota Cressida (same motor as MKIII Supra) and sent them off to be professionally cleaned. They are the non-air assist type. I ran those injectors while naturally aspirated first, and didn't have any issues. Not having the air assist port blocked off was creating a bit of a vacuum leak, so I blocked off the air assist hose at the y-fitting when I installed the turbo and it still runs great. I think air assist is over rated IMO.

Air Assist only helped under vacuum as when we put the one-way check valve in and build boost, the air flow would actually flow backwards back into the intake without it. So under boost it's just a regular injector. I've been fighting low idle for as long as I had the non Air Assist brown tops. I had to actually adjust the non-adjustable throttle body idle speed and break off the factory paint marks and dive into the unknown. Turns out it's not that hard to do but I'd rather not do that at all.

For the check valve question, try Home - Superchargers Online. They sell parts from Magnuson and odds and ends they don't list on the website. Just reach out. If they say no, try URD next.
 
Anyone got pictures of how to hook up a 1st gen grey charger for the existing vacuum hoses and stuff. I just got done installing 2 knock sensors, knock sensor wiring harness, 295cc injectors, complete valve cover gaskets, and complete timing belt kit (belt, pulleys, cam seals, crank seal, water pump, 170* thermostat, k22 plugs). I have the diagram, but I’m a visual kind of guy. Any help is greatly appreciated. [emoji1686]


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Charger is on. Just have to finish the timing belt.
e9cfb421f1794ecdafaaaabf2ac66b5c.jpg
 
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I've been fighting a problem for a while and want to see if you guys have any input.




My 98 3.4 SC manual falls on it's face and pulls all timing until around 3500 rpm, then it pulls "ok". I do have the URD / split second FTC piggyback.


I thought I was having a knock sensor issue, which I have the GM style external bolted to the head setup and have had that on the truck since shortly after the rebuild and SC install roughly 50k ago. Have installed new sensors, remotely put them in the glovebox covered in foam, and disconnected them. Disconnected resulted in a CEL and pulling all the timing completely.

With all that being said, It's looking like the factory ecu or the piggyback. Has anyone had a similar problem? Any way to test either or send either off for testing / repair?

I'm strongly considering a stadalone ecu, but don't know where to start...
 
I've been fighting a problem for a while and want to see if you guys have any input.

My 98 3.4 SC manual falls on it's face and pulls all timing until around 3500 rpm, then it pulls "ok". I do have the URD / split second FTC piggyback.


I thought I was having a knock sensor issue, which I have the GM style external bolted to the head setup and have had that on the truck since shortly after the rebuild and SC install roughly 50k ago. Have installed new sensors, remotely put them in the glovebox covered in foam, and disconnected them. Disconnected resulted in a CEL and pulling all the timing completely.

With all that being said, It's looking like the factory ecu or the piggyback. Has anyone had a similar problem? Any way to test either or send either off for testing / repair?

I'm strongly considering a stadalone ecu, but don't know where to start...

There's nothing magical about 3500 RPM but it could be an open loop/closed loop dynamic. If you are really mashing it, it will downshift to about 3500 RPM and switch to open loop in which the piggyback alters the signals to add more fuel and pull some timing. That makes me think it's not the piggyback and instead you've got a rogue sensor feeding bad data in closed loop. The sensors that could be on the suspect list are:

Mass Airflow Sensor
Ignition/coils/spark plugs (some engines eat spark plugs in 15K miles)
Oxygen sensor, upstream
Throttle Position Sensor (this can fail with no code)

That should get you started. I am not saying these all have to be replaced, just tested. First thing to check is the plugs and not just a visual check. Measure the spark gap. Should be no larger than 0.035" but ideally 0.032". Once you get above 0.035" you'll start to lose power under high boost situations. Once you go over 0.038 you'll start having misfires and severe hesitation under heavy throttle. More than once I've helped a friend with hesitation like this and found out there's a worn out or damaged spark plug.

From there, clean the MAF and test the TPS as outlined in the factory service manual. The O2 sensor is about $50 on Amazon and can be replaced anyway if has never been done and should improve things a little.
 
Need Help - Dynamic Tensioner Issue

Hello all,

I have been dealing with an issue that has finally led to my SC belt being just about shredded. For some background, I got my 4Runner ~8k miles ago, where the PO installed the SC about 50k miles ago at this point. When I got the rig, I did knock sensors and a timing belt job. At that time, the belt looked fine but I noticed serious wear to the URD idler pulley on the dynamic tensioner.

State of idler pulley:IMG-0384 hosted at ImgBB — ImgBB

I knew this was an issue when I first got the rig; there is serious wear on the main pulley surface as well as wear along the "retaining wall" on the engine-side. However, it didn't cause any issues and I didn't want to mess with it.

Then, after I did the knock sensors & TB job, the threads that the long bolt of the dynamic tensioner thread into in the block were stripped. Due to the wear on the pulley before I took it all apart, I'm assuming they cross-threaded the tensioner on initial install. I fixed this with a Helicoil & Loctite which has held up so far.

Long story short, it seems like the idler pulley is out of alignment, causing this issue: IMG-0420 hosted at ImgBB — ImgBB

I also believe I've been dealing with belt slip during my ownership, as first gear doesn't pull as much boost as second. Plus, with the wear on the idler, something is definitely very wrong.

I found an old post where someone experienced belt slip, which was fixed by a new tensioner. However, my torsional spring seems to still be quite stiff.

Does anyone have any experience with this sort of issue? I can physically bend the arm of the dynamic tensioner away from the engine, making its misalignment worse... could there be some way that my tensioner is slightly worn out? Without belt tension, I can feel play in the bearing of the URD idler, likely making matters worse. I have my eye on the Dayco 82941 / 89007 combo to replace the dynamic tensioner if needed, but I'm hesitant that the issue will be solved.

Apologies for the long writeup, but wanted to try to get as much info out in one post. Any help is greatly appreciated!
 
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TVS1320 hood clearance?

Hey guys, I just got done with my first test drive of with the new Magnuson TVS1320 blower installed (stock boost - 65mm pulley and 7th injector install pending). It looks like it is rubbing on the hood insulation (and likely would rub through and get to a hood rib with time). Anyone else experience this?

I have no body lift and have poly body mounts. I will be checking to see the condition of the engine mounts (still original at 326k miles...) when I get back to the truck on the way home from the office (brake torque in gear).

A while back, I did have some 1/4" body mount spacers made - maybe its time to install those - and just cut out that interfering rib on the hood...

Thoughts?

-Charlie
 
A while back, I did have some 1/4" body mount spacers made - maybe its time to install those - and just cut out that interfering rib on the hood...

Thoughts?

-Charlie
Hood rib cut. Mechanical install complete... runs well with the stock pulley with no fuel/timing mods for the moment. The engine bay portion of the 7th injector is done and hidden.

I've been fighting P0420 and P0446 codes for a few years now. Looks like I found the P0446 - it was a crack in my evap canister. That's been sealed. I also put on a short O2 sensor extension (both AFR and rear O2 are ~2 year old Densos). Looks like I'm on the right path. Cat readiness monitor set correctly on the way to work this morning and I heard vacuum release from the fuel tank when I filled it up this morning for the first time in years...

L036zLf.jpg


-Charlie
 
65mm pulley installed. I had a wiring snafu (caused by me) in 7th injector kit that kept the truck from starting... but now that that its fixed, the party is really going. ~7psi here near sea level.

b0OqXkMh.jpg


-Charlie
 
65mm pulley installed. I had a wiring snafu (caused by me) in 7th injector kit that kept the truck from starting... but now that that its fixed, the party is really going. ~7psi here near sea level.

-Charlie



MY GUY!!!!

now you got some serious SICMODS in your engine bay!


so if I understand correctly, even before you installed the 7th injector, you were NOT experiencing any engine pinging?




 
so if I understand correctly, even before you installed the 7th injector, you were NOT experiencing any engine pinging?
Yup, the engine was happy with the stock boost - even with CA 91 octane. I think having 4.88 gears helps - it is rarely below 2k rpm. I'll check once I get the boost gauge installed, but I think stock boost on the TVS1320 supercharger is really low - like 3-4psi, even at sea level. The ~7psi number I saw when checking what the 7th injector computer saw with the upgraded pulley. Exhaust is 100% stock. ISR and deck plate mod on the intake side.

I will likely need a bit of tuning up top since the URD off-the-shelf maps are supposedly only good to the 70mm pulley (I have the 65).

-Charlie
 
I realized I didn't post anything about how I did the 7th injector fuel line...

Instead of the line over the top of the supercharger to a T in the cut fuel inlet line, I ran my line to this:

URDFuelRailTapx500.jpg


A URD fuel rail tap, sandwiched between the fuel rail and the regulator. It is very tight back there and you have to modify the harness to clear and route around the extended regulator and get different lines/fittings, but it makes things REALLY clean:

Cr9BVsa.jpg


This was in place and all hooked up at my local smog shop that is VERY strict and he didn't notice it. The injector wires and vacuum line are routed through the stock harness boots from right at the engine, so nothing is visible over there.

Wideband bung is also installed:
nREShY3h.jpg


Nothing special there. I'll be using an Innovate PSB-1 AFR+boost gauge. It also has a tach input, so I can log the same parameters as the 7th injector map uses and make sure things are tuned well. Still have to hook up a few more wires before testing that.

-Charlie
 

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