Catastrophic Failure, 2uzfe. Rebuild questions

The 1UZFE EGR Delete Kit is available for sale here.


New Member
I blew up the motor in my 2005 4Runner Sport. I got forced off the highway in a near-accident in the middle of a bad storm, and plowed into deep water at 50mph. Apparently got water in the intake and hydrolocked the motor. Dropped the oil pan and found pieces of the #2 rod and what looks like an oil tube.

I pulled the motor and plan to bring it to a shop in Modesto called Yota1 Performance, which has a full machine shop and specializes in building motors. Will have to wait for the verdict on block damage. I've been reading the threads here, and I'm hoping for a little advice on planning my rebuild.

Background: My truck is both my daily driver (only a 6-mile roundtrip local commute, no freeway), and my adventure mobile. A lot of trips to the Sierras every year. A lot of mild off-roading, including snow and mud. The truck is lifted, 33-inch tires, Icon and total chaos suspension. It gets a work out, but no rock crawling or racing.

Objective: As much as I love power, I'm planning to keep it NA. My hope is to get 320-350 HP at the crank, and still have a bullet-proof motor that won't leave me stranded 20 miles from the nearest paved road.

Plan so far: headers, hi-flow cat-back exhaust. ECU tune. (CAI? Hearing mixed reviews on impact.)

Need advice:
Target for compression
Forged rods and pistons selection
Heads (currently has stock heads, VVTI)
Cam and valve train
Other considerations?

Any advice is welcome. Happy to post back on my experience.
This is what I found when I dropped the oil pan. I'll get the motor to the shop this weekend. Hopefully when they tear it down they'll find the block is still good.

Sorry to read of your issues; the rods are the weak link with the UZ motors. I don't have much advice for you, other than it may be cheaper/easier to grab another junkyard pull than to rebuild the existing motor. These engines are really expensive to hotrod.

Also noticed we share the same family name!
Thank you for the reply. I've read a lot of your posts, so I definitely appreciate your input. I got fortunate--my comprehensive insurance coverage actually paid out for the damage, because it was a highway incident. They paid against an estimate for a mechanic to replace the motor with a junkyard motor. So I've got about $6k budget to spend on the rebuild. I love my truck--the v8 4runners are beasts, and the run only lasted a few years, so I'm planning on holding on to it. I'll have a fresh motor and if I'm lucky, a bit more horsepower. :)
Last edited:
Good to hear you got another motor.

The bottom item is an oil squirter that bolts into the main oil gallery that runs under the plenum.

I would expect the block to be stripped where that fitting came from and I wouldn't trust any repair there as it's a main oil gallery and if it came adrift it would be even more catastrophic.

You couldn't weld the hole up and red-rill and tap without the risk of a bur coming adrift at some later point in time.

The replacement engine is the best move.
Good to hear you got another motor.

The bottom item is an oil squirter that bolts into the main oil gallery that runs under the plenum.

I would expect the block to be stripped where that fitting came from and I wouldn't trust any repair there as it's a main oil gallery and if it came adrift it would be even more catastrophic.

You couldn't weld the hole up and red-rill and tap without the risk of a bur coming adrift at some later point in time.

The replacement engine is the best move.

That is a huge tip. Thank you! I'll talk about that with the shop today. They have several 2uz blocks available in the shop. I know people have said you can't expect a 2uz junkyard motor from a different year/model to hook up directly in your engine bay--sensors, hoses can be different, etc.--do you happen to know if that applies at the level of the iron block? Or are those only a problem when you're trying to do a long block swap? Thanks for the tip!
So, quick update. Block did indeed turn out to be shot. Big hole in the gallery wall. So really starting from the ground up now. Crank and heads were fine.

Still planning to keep in NA for now, but questioning whether to increase compression. I found a compression calculator online,, which claims that going from 9.5:1 to 10:1 will only net an increase in 1 hp. It doesn't calculate any changes in timing, which with forged internals I should be able to advance, so I'm not sure that's an accurate picture, but at any rate, it seems like a small gain to trade for cutting off the potential for boost some time in the future.

The next piece of the puzzle I'm trying to work out is a set of cams. Waiting to hear from Crower about their options. If anyone has any recommendations based on experience, I'm trying to learn what I can. Thanks.
I'd talk to Kelford cams in New Zealand.

They would have more experience with UZ cams than anyone.

Gloverman (kelvin) on this site would also be a good person to ask advice or obtain parts from.

You can't increase compression by shaving heads as this mucks up the cam timing big time. Well you can but the timing will be all over the place.
I exchanged emails with Josh at Kelford. He said their 2uz VVTI cams will be on the market in 5-6 weeks. Also checking with Crower. I checked Isky (I have a set of their cams on my 65 mustang), but it looks like they have nothing for Toyota.
Got a helpful follow up from Josh at Kelford today, with a list of all the UZ cams they're shipping in 6 weeks, with specs. There's a road cam and set of springs will work with the stock heads and an ECU. Josh thinks that set up will put out up to 360hp without boost. Still a lot of other wrinkles to iron out, though.

My next task is picking an ECU and finding a tuner. I was looking at a piggy back ecu, and was reading up on Megasquirt and ECU Map 3, but Gloverman has been kindly offering some advice. He strongly suggested I go with a dedicated ECU, especially as one of my requirements is to pass California smog, and he thinks I won't be able to get the tune right with the stock ECU. As he put it, might as well get that right the first time, and I definitely trust his experience. Exactly how I'll get it set up to pass smog, I'm not sure yet. The hardest part right now seems to be finding a tuner in the Bay Area that knows anything about tuning 2uzs.
Quite happy to report that I placed the official purchase order today with Kelford. They're being milled this week and shipped out next, right on time. Josh couldn't have been more helpful. Really pleased.

Web Cams, by contrast, literally wouldn't give me the time of day on the phone. When I said I was looking for 2uz cams, their first response, no exageration, was... "well... they'll be at least $2500". Not, yes! we have the cams you want. Just a snobby price push off. No thanks. Crower never even called me back.

So at least for being helpful, promoting a product with some R&D and experience behind it, and shipping when they said they would, 5 stars for Kelford.
Cams are on the way, build will commence shortly. I'm going to be faced with a decision soon on ECU and would love some feedback. Link Xtreme seems to be the preferred ECU among Kelford fans. AEM Infinity is a bit more familiar to my tuner. Aside from brand preference, are there any significant objective advantages/disadvantages that separate them? Cost seems to be roughly similar--around $1500 US.
Kelvin (Gloverman) is an ace with these engines and the Link ECU and can probably get you a great tune without ever seeing the engine.

The most important decision with picking an ECU is not the ECU itself, but picking the right tuner for it. So I wouldn't spend that much time poring over ECU specs as I would getting recommendations for solid tuners. Most tuners think that getting the absolute maximum power out of an engine is the right tune, but for a daily driver maximum power is useless if the thing is undriveable, won't idle, or stalls every time you let the clutch out. That's the tune that a well respected AEM tuner gave to me for my 2JZ-GTE Supra many years ago.
I keep saying I know nothing but no one seems to believe me. Haha.

Tuners that make undrivable cars annoy me. Powerful can be smooth, idle and still do everything like normal but go much better.

It's been awhile. I finally got my build together. Had a bit of a delay when the Kelford cams didn't initially fit. The exhausts were fine, but the intakes were different. There's apparently a variant in the 2uz vvti head in North America that is slightly different. I'll post Kiel's comments about it, which are interesting. They were great about it--I sent the original intakes and they rebuilt them to the same spec at no additional charge.

I'm just about ready to fire the engine up, and I would value any smart advice for the weekend mechanic over here. I'm scared shitless to screw this up. I've done my homework on start up and run in routines, but I've still got some questions. Here's my plan, and then the questions. Would love any wisdom you can offer.

1. The motor was built as a higher compression (9.5:1) N/A motor. Forged rods and pistons (Eagle and RaceTec), Kelford's 208-B cams. The heads have been ported. It's running stock intake and injectors. It's running stock exhaust for now as well.

2. It's currently got only the stock ECU. The builder believes the stock ECU will run the engine, so my tentative plan is to run it in before taking it to the tuner for an ECU install and tune.

3. I've got run in oil with zinc. New fuel filter. Triple checked all the hoses and connections.

4. My plan is to fire it up, run it for 20 minutes continuously cycling to different low to low-mid RPMs, but not leave at idle. Monitor oil pressure and look for leaks. Dump the oil and oil filter, and look for anything ominous. New oil and filter, and a cycle of road sprints, 30(mph)-60-30-60 etc. to set the rings. Then drive it moderately around town over the next couple of weeks until I reach 500 miles. Change the oil and oil filter. Off to the tuner.

Here are my questions:

1. Should I manually prime the EFI, or will it self prime? I'm used to working on old Mustangs with carburetors. Working on EFI is new to me. I've read some accounts that you should jump the fuse box connectors to run the fuel pump on its own to prime it. I've read some accounts that you should loosen the union joints on the fuel rails and run the pump until fuel comes out. I've read some accounts that you should just turn the key on without cranking for 3 seconds, turn off for ten seconds and on for 3, repeat a few times. This is a 2005 4runner. Will it self prime on ignition?

2. Is there any reason to think the stock ECU would be a problem for start up?

3. I also overhauled the automatic transmission. I put a quart in the torque converter. The FSM says you need to run the tranny through the gears after start up, and add more fluid as it gets drawn into the system. I haven't yet reinstalled the transaxle (4wd), so my plan is to just run it through the gears in the driveway while I'm doing the first fire-up and 20-minute run-in. If I have my son manage the throttle, can I keep the fill plug open while the engine is running and keep adding tranny fluid until it hits the factory capacity? Or is there enough pressure in the system to spray fluid out of the fill plug?

Rabbits feet? Hail Marys? What else am I missing?

Thanks for your help. Below are the comments from Kiel at Kelford about the cams for anyone interested:

"Our exhaust cams are identical so they’re still at Yota1 to be fitted and we got back your intakes cams, our intake cams and also a pair of dud heads that Nick had lying around for our records. We have your intake cams in the workshop to be welded and ground to the specs of 208-B and we’re hoping to ship this week.

It appears we were somewhat mislead with the R&D parts we got to commission these cams for all of the UZ VVTi’s, but we have confirmed the 1UZ and 3UZ are compatible definitely now. There could still be a variant of the 2UZ that they work with but we haven’t found it yet if it exists.

The 2UZ VVTi has a different snout to the 1UZ and 3UZ VVTi where the phaser goes on. They’re painfully similar but the nose of the 2UZ is shorter with slightly different machining for the oil passages, otherwise the cams are identical. It does appear to be something the raw castings we had made can be machined to but it won’t be until our next stock run of them which will be some time now unfortunately.

For what it’s worth the thrust surfaces in the heads are ever so slightly different too."
Sounds like good progress is being made.

Interesting on the camshafts. I'm playing with a few 2uz bits and they are interestingly and annoyingly different.

For startup I would crank up oil pressure first (fuel injectors and spark disabled). This should give the fuel pump enough time to fill the rails.

Then have everything good to go, start and warm up keeping an eye on everything. Once warm and checked over I would be driving with a wideband attached to ensure mixture is in the ballpark and be watching the knock control through the ECU.

Can you confirm the compression ratio on your 2uz standard? Again exact specs seem to differ.
As Kelvin said, make sure you have oil pressure first before you actually run it. The UZ oil pumps are not known for their ability to self prime.