1jz vvti wont idle mx73

[sundee86]

sundee86
regarding resetting procedure, there's none, however here's what it says
disconnect water temp sensor (for efi, that with 2 wires) , turn ignition on, disconnect and connect ISCV connector
Each time you disconnect and reconnect it (when ignition is ON) it must cycle from fully open to fully close to half open

Did this just now - could not hear or feel the iacv function

I am bout to run it for 15min at 2000 rpm to see if helps the situ.

[sundee86]

Tested mrel output from ecu... Ecu is outputting 12v for 3 seconds after shutdown.

[George]

have you also tried the presumably good IACV?

[dumbass]

if the iac power drops off straight away and not 3 seconds
I recon u have wired the black/red that powers idle motor and auto box and o2 sensor and the vac solenoids to samepower as injectors
and not to the efi relay output power

[wilbo666]

Most of this has been covered already...
http://wilbo666.pbworks.com/w/page/4...CV%29%20Wiring

Have you checked / confirmed that the ISCV is being supplied power after ignition is switched off for a few seconds? (check the middle two pins of the 6 pin ISCV plug when the ignition is switched off)...



Cheers
Wilbo

[sundee86]

Doesn't the B/R from EFI main power injectors and B/Y from MRel power other sensors?
Since the Mrel output from ecu powers the coil in Mrel, which powers the coil in EFI main rel and CO rel?
How does that make a difference?
Only asking because I'm pretty new to this wiring biz .

I ran the car for 15min at approx 2000rpm... Shut it down, re started... And it started in assisted and idled on its own!
Stoked! Going to wait till the morning to see of the cold start works.

[sundee86]

Hey wilbo, posted this a few posts ago:
Thanks for the link, I'll check it out

Just got some odd reading from the tps.

E2 - VC closed : 3.53 Kohms (tick)
E2 - VTA closed : 3.12 Kohms (tick)

E2 - VTA open : 0.8 Kohms ... This is odd

Tps fail? Showing no tps error codes and car drives fine, it's just the idle that's the issue .

BK_ I only realised while testing the tps the other day, that there was no idol switch in the tps aswel.

I just tested the iacv +ve terminals.
Started car, running ,terminals had over 13.5v
Ign switch to acc - terminals lost power what seemed to be instantly!

The ecu is storing fault codes fine though.....

[dumbass]

ecu gets power at igsw wire
then mrel wire positively triggers efi relay

efi relay powers ecu at +b abd +b1 and also powers idle motor and auto and some vac solenoids and o2 and COR

spark plug coils and ignitor and injectors get power straight from ign switch or an ign relay


COR gets power from efi relay and is triggered by FC pin but most late model ecus don't have fc pin they have fuel pump ecu
so I get modules made up to trigger COR thru rpm

most people think that these small wiring isseus don't cause many problems
but its hit n miss sometimes how bad the engine runs if they are not wired properly

[dumbass]

also I never check tps using ohms its to easy to get bad readings even though Toyota gives u those settings

at idle u need around 0.6 v and slowly climb to 3.9 or 4 v
atleast testing the voltage u are checking it under load

[wilbo666]

I just tested the iacv +ve terminals.
Started car, running ,terminals had over 13.5v
Ign switch to acc - terminals lost power what seemed to be instantly!

This is incorrect and I would strongly suggest your problem!



Cheers
Wilbo

[sundee86]

Yeah I figured as much wilbo, your page has great info! .... Now just to find out why.. I assume it's the way I have wired to power to the sensors etc. (forehead slap)

[dumbass]

I think most people get to over excited about testing tps and don't worry about the real problem
testing tps is a 5 second process so don't waste to many days on it hehehe

tps hardly ever fail and should never ever be adjusted until all other avenues are exhausted
that's y Toyota put yellow or white paint on the screws

[sundee86]

Tried cold start this morning... No love.

I found I had wired the iacv to the EFI relay +12 constant.
Now re wired to EFI relay switched + 12 v.

Now to tidy up wiring an see how it goes.

[sundee86]

Just going to reply incase anyone else has this issue in the future..
The issue was the incorrect wiring of the iacv +12.
I had it coming from the ignition side, instead of it being powered by the Mrel.
Re wired it, and happy days.
Runs like a gem!

Side note - went to swap out the fuel pump today..
Mr toyota, why do you make me drop the entire tank to change a measly pump?

Thanks for everyone's help, appreciate it

[dumbass]

that's the biggest mistake backyarders make
idle motor does not have a chance to reset once u turn ign off