1uz vvti - bypassing heater

[aniesigh]

Hi all, have fitted a vvti 1uz into my comp 4x4 which has no heater so i need to bypass the hoses for it, am i better blocking them both off or connecting them together? have got them connected together at the minute but seem to be struggling to bleed cooling system. (running davies craig elec water pump with radiator mounted in rear)

Also have very low idle at the minute, do the iacv play up on the vvti motors?
Can't seem to get techstream to connect so can't pull any fault codes.
if that is just how it idles, can it be upped at all?

 

[gloverman]

I always block them when not running a heater core. In the factory situation the core acts as a cooler. Without this you have a uncooled passage for the coolant to circulate. The 1uz VVti have a bleeder on the top of the throttle body.

Idle speed is wire it correctly and leave it alone.

 

[George_R]

Yes idle speed can be raised up to 650 RPM, when transmission is in D range

In a completely stock 1999 LS400, idle speed is 550 RPM (when in D) . If you turn on headlights or rear window defogger (or both), the idle speed would then jump to 650 RPM to ensure enough current from alternator.

Engine ECU for vvti models "sense" electrical load by waiting for a special command on the digital communication line (labeled MPX on the wiring diagram). This signal is normally transmitted by Body Control ECU.

I could replicate the signal so I don't need BCU any more for idle up. I even wrote an article on the topic, but unfortunately Zuffen failed to post it somewhere on Lextreme.

 

[Zuffen]

I have my heater hoses blocked and have no problem in Australia's warm climate.

Although it is chilly in winter!

Maybe if my car a roof or doors it would help.

 

[aniesigh]

I'll block the hoses then, cheers!

George do you have a supply of ecu's? I think I need your services but wouldn't mind a spare Ecu so keep the one I've got and get another from you with raised idle, sub o2's and immo removed!

Cheers

 

[George_R]

aniesigh my services is offtopic here bet yes I usually got some ECUs in stock. Mostly JDM