1jz wont rev past ~2500rpm *SOLVED*

[CrUZida]

Yeah, and its pretty much all useless in Australia. (unless you live somewhere uber cold).

[Hydra]

So, I'd be best off removing it from my 1JZ? Perhaps with the exception of the ISCV (doesn't this use bi-metal to actuate the valve or something?)

[wilbo666]

So, I'd be best off removing it from my 1JZ? Perhaps with the exception of the ISCV (doesn't this use bi-metal to actuate the valve or something?)

Really, really old ISCVs use a bimetalic strip...

Have a search on how the 1JZ ISCV works...in short there is a little stepper motor that is driven by the ECU to open / close (let more / less air in).

It has coolant around it so it doesn't freeze shut in really cold climates

Cheers
Wilbo

[Hydra]

Sweet, thanks!

That'll save me some space getting rid of those pipes

[JZA70 R]

there is no measurable performance gain by removing either of these water routes due to the fact the intake manifold will heatsoak within 20 minutes of driving anyway. However, if you have a passion for deleting unneccessary things things in your engine bay, this would be a great place to start. It will allow easier access the oil filter, and simplify and neaten the engine bay.

[Kyosho]

I have heard of people in Australia actually needing it, whilst cruising...
Basically, whilst cruising, in deep vacuum, pressure drop, ends in a huge temp drop... In cool condition, causes freezing...

[JZA70 R]

not possible with a 1JZ retaining the stock intake manifold im sorry as it acts as a heatsink for the head. a large percentage of heat from the head, is passed through to the intake manifold, this is why it heatsoaks so badly.

ill gaurantee you that you could drive around in canberra in the middle of winter with no bonnet and still you wont be able to hold your hand on the intake manifold for more than a second.

[AeRoKaBn]

sorry wrong post

[Hydra]

I'll see how worth while it is removing it today with any luck... Got a few other coolant hoses that don't appear to have clamps to worry about first, d'oh!

[takai]

Hm, iinteresting. Im getting choking at around 2500rpm too. Maybe i have mucked up the washers on the dampener.

[Hydra]

Decided that I didn't have enough time to worry about chasing down every hose going to and from something related to heating the plenum/iscv, so I just put some new hose clamps on, tightened up about 5 bolts that were about 5mm away from being in correctly and connected up the bov (whoosh!). Still no wastegate on the rear turbo Not sure what I'll do there yet - need some mig welder love to get that going. And there is an exhaust leak somewhere near the turbos. More work

[RObErT_RaTh]

Glad to hear you got the idle problem solved buddy One step at a time

[Hydra]

Haha you should see what I'm bodging up to get the muffler on there for the moment - it's far too loud to drive to an exhaust shop right now

[RObErT_RaTh]

Show me and if it's better than what I can do I might get you to do mine lol

[lexsmaz]

Good to hear that you have fixed the problem, but i am wondering if the damper & fuel filter are actually accidently fitted on the return rail, because if it was restricting the fuel as you mentioned, the plugs shouldn't be black & the injector pulse width should be quite large if it is dying of fuel ? Where as if its restricting returning fuel, that explains the narrow pulse width & black plugs ..
Or maybe just way to much fuel pressure from the pump ? .....