Hey all, just wanted to post an FYI for anybody going through the same hell that I endured for the last two months:

After replacing my 3.4L supercharger (with 200k miles on it) with a new 2nd-gen model and URD 7th injector kit with 2.2" pulley, the truck was running like crap.

Basically, the truck's acceleration was hesitant and rough. It would do fine until the supercharger started really kicking in (around 2600 to 3000 rpm), then would cut out and barely rev. But the biggest problem was a lean backfire that occurred when downshifting.

While cruising along at ~40 mph, if I stepped on it, and the tranny downshifted, it would cough and sputter and backfire. I THREW 3 ALTERNATOR BELTS THIS WAY!!! I ended up spending a small fortune troubleshooting the problem with a local tuning shop (btw, Gadget at URD did his best, too).

Long story short (actually, a VERY long story), I chased down the part number for the IAC (Idle Air Control) check valve -- that wasn't provided with my s/c kit -- and installed it out of sheer desperation.

$5.99 (plus tax) and 3 minutes later, the problem was cured. AMAZING. Truck runs like a champ. I wish I would've known about it when I first installed the kit!!!

For anyone encountering this issue with a 3.4L TRD supercharger, here's the new Toyota part number for a 1-way IAC check valve (since the TRD part number won't work anymore and the idiots at dealerships won't help you find it):

PTR26-35042

Install it. The directions say you don't need to for certain models, but install it anyway (when installed correctly, valve should block air from entering the throttle body).

Anyway, I really hope this helps someone down the line!!! <img src="/forums/images/graemlins/scared.gif" alt="" />

For the money you guys throw into this mod, this is an AWESOME bit of info. Thanks Burly!!!

Actually been a pretty repetitive problem lately. A few people on customtacos had this problem (were you one of them?)
Also, what did you do with your old s/c? you could have had it rebuilt for 500 bucks...

I'm unclear - where does that check valve get installed?

That's really good that your first S/C lasted 200K miles, particularly since you can't easily replace the oil on the 1st gen S/C's.

My 2nd gen TRD supercharger (black) was overhauled by Magnuson and they said they had to replace just about every component of it. It cost about $1000 for the overhaul. That was despite replacing the supercharger oil with fresh supercharger oil a couple times during those first 110K miles.

I believe they suggest replacing the nose drive or atleast getting it rebuilt even 60-70k miles. If you replace that and the bearings in the back, the rotors should be fine, i'm guessing that's what added 500 more.
But yea i missed that, 200k on teh s/c without maintenance? that's nuts!

Part of the cost of the overhaul on my S/C was they claimed they HAD to replace the housing. They didn't give me a good reason. But yes, normally it's just the nose drive and bearings and labor, which they originally quoted me $670.

As for where to install the check valve: It installs inline with the Idle Air Control vacuum line (on the bottom backside of the throttle body - it's the hose WITHOUT clamps).

And ya, that S/C went over 200k miles without a rebuild. Dangerous? Yes. I know.
I never got it done because I drive the truck every day and it would be very difficult to remove it, ship it in, then wait to get it back, so I just kept putting it off, putting it off, and putting it off. <img src="/forums/images/graemlins/scared.gif" alt="" /> Plus, Magnuson told me the same spiel about having to replace everything; it would've cost almost as much to rebuild it as it was to buy a new one.

Btw, no notching or grinding from the nose drive in that old blower, and no leaking oil. I think I really just got lucky...

And Greg, I wasn't one of those guys from the other sites. But I'm tellin' you, I really wish I would've found those threads before throwing fistfuls of cash at the problem! Haha!

OK, thanks for the additional info.

BTW, my nose drive/bearings did have a faint notchy feel before replacement, so that's awesome that yours lasted that long and still didn't feel bad.

There are some pics in this thread,
http://www.customtacos.com/forum/showthread.php?t=135790

I'm totally laughing my a$$ off now. I searched for weeks about this problem when I was going through it, and couldn't find any relevant information. Now that it's fixed, I see there were a lot of others going through the same problem. I guess I just wasn't searching for the right keywords...
No offense to Gadget, but a lot of the stuff he was saying was just not making practical sense, and I would think that he (and others) would consider a $5.99 part over more extensive tuning and additional aftermarket parts - especially if this problem is somewhat commonplace.

But whatever. It's fixed, the truck is SUPER fast, and the world is a better place with my blood pressure back down to normal these days... <img src="/forums/images/graemlins/cheers.gif" alt="" />

Thanks for the support, guys. <img src="/forums/images/graemlins/patriot.gif" alt="" />