1UZ VVTi In IS200 - Using Stock Rad, Fuel Pump etc

[adarmo]

I have bought an IS200 which has had a 1UZ VVTi installed by the previous owner.

It doesn't feel as quick as I thought it would.

In essence he has ONLY used the 1UZ engine and ECU everything else is stock:

Gearbox, fuel pump, rad, axle etc

Has anyone got experience as I find it hard to believe that the items designed to run 150ish bhp can cope running 300ish bhp

In fairness I have taken it for a decent run and it doesn't overheat (albeit it's only 10 degrees today) and generally drives well and is far more civilised that I expected.

 

[gloverman]

The 1uz VVti is rated in stock form at 300hp at the fly. I always like to check conversions on a dyno to see that they are making what they should. I've found some which are well down on what they should be. The 1uz go well and are often quite civilised , especially in a stable chassis.

That said I've run 300rwkw (400rwhp) 2JZ in Altezza (Toyota's equilivant) on stock radiators. After that they need upgrading. Stock fuel pump is well up to the job if they are healthy.

 

[adarmo]

Thanks.

I was thinking the dyno and / or an AFR gauge is my next step

It has been professionally wired in and the VVT seems to be working it's just far more civilised than I was hoping for - my 240bhp Supercharged MX5 is far livelier.

On another forum it's been suggested the ECT switch on the gearbox (in the LS400) also affects the throttle - do you know if that's the case ?

 

[gloverman]

If the gearbox part of the LS400 ecu isnt wired correctly you would know. They don't rev correctly.

Is it running the IS200 6 speed manual?

One common failure is the ACIS solenoid. I replace them on around 50% of the VVti engines I work on. They make the performance lacking down low. Easy to check for movement on the lever assembly on the back of the plenum at startup.

Also have you run a scan tool on it to monitor everything is working? The O2 trims will indicate how close the mixtures are.

 

[adarmo]

It's ok then as it revs fine.

Yes - so it's pretty low geared - I expected it to struggle to get the power down.

Thanks I'll look into it.

I tried to connect a mate's Snapon Modis earlier today but it seems it can't communicate with pre 2000 cars even on OBDII

 

[adarmo]

Update: Gloverman - spot on diagnosis - the ACIS wasn't working - cable tied it down and it feels like a V8 should.

Just have to fix it properly now to get the top end back.

Thanks

 

[gloverman]

Thanks for the update. I always buy new solenoids. I saw a tend a few years ago and find about 50% the the engines I work on they are stuffed.

 

[adarmo]

I don't suppose you know the part number ?

I've googled it to death and spoken to my (unhelpful) Lexus Dealer

They think I need 17650 No.1 25860-50110 but no one seems to mention that part no.

I think I need 17650 No.2 25860-50121 which a few people mention (albeit with later cars)

I'd rather order one before taking it apart as they say it's a special order and has to come from Japan - taking 3 weeks !

 

[gloverman]

You require VSV No2 so I am quite confident 25860-50121 is the correct part. (I checked it on the toyota parts ordering system that I have access to over here in NZ as I sell lots of toyota parts). early engines used 25860-50120 but this superceeds to 121 which is used in the 3uz as well. No1 vsv changed in the 3uz. .

 

[adarmo]

Thanks again.

I have gone to order the part and after checking my donor's Chassis No. JT153UF2000131082 they have said that 25860-50121 won't fit and I need

Lexus Vacuum Switching Valve No.2 90910-12183

Part cost: £85.56 BUT that it is obsolete

Googling that part no. gives me 17650E which does not appear to be the No2 valve so it's possible they've made a mistake.

It looks like I'll have to take it apart and see - perhaps putting it back together extending the connections so that I can later plug in the valve remotely.

Presumably it isn't rocket science to modify it to take the later valve - from parts diagrams it appears to have two electrical and two vacc connections or am I missing something ?

 

[gloverman]

Dealers can be so hard to deal with at times but there are some times I understand when I see the information they have to work with. Luckily I have access to the ordering system and all the correct diagrams. Below a link (hopefully) which is a copy of the toyota system. The way I take it 90910-12183 is the valve for the fuel tank breather located on top of the manifold. Now if you look at it 25860-50110 is the same valve with the bracket attached which would explain why 90910-12183 is obsolete, they now sell it as a complete unit with valve and bracket.

The part you require is the valve under the manifold which is VSV No2. 25860-50120 which then swaps to 25860-50121.

Toyota part numbers are quite simple once you get to know them. the first 5 digits are the part group. the next two are the model number. 50 is Celsior the next are the part number with the last digit being each supercession. They start at 0 then 1 then 2 etc.

https://www.megazip.net/zapchasti-d...7211/ucf20-aeank-427570/vacuum-piping-5559824

Ill see if I get some time today to make it even simplier with some photos. I think I have all the bits here.

 

[gloverman]

This is the vsv No 1 which is the breather for the fuel tank. I've taken the photo on the engine so not to be confused. Note the hose fittings.

 

[gloverman]

And the part number on it. This is a 20 series vvti engine. Remember this is the No1 vsv

 

[gloverman]

Now I've sliped

 

[gloverman]

Let's try again. I've slipped the manifold off and it looks like this.

 

[gloverman]

Solenoid vsv No2 and catch tank.

 

[gloverman]

Now this is a later engine with a different part number which may help you. It's listed on toyodiy for lots of models

 

[cribbj]

Kelvin, in case no one has mentioned it to you lately, you're an incredible resource. Thanks for all you do!

 

[adarmo]

That's fantastic.

Thank you.

 

[adarmo]

To wrap this up I ordered the 25860-50121 valve from Parts Souq who are in the UAE as they had them in stock and were 1/3 the price of Lexus.

It arrived within 3 days.

Stripped the manifold off and it IS the exact part I had fitted - so Gloverman was right and Lexus UK got it wrong three times !