idle issues

[whynot]

Well I seem to be having all sorts of strange issues with this car the latest a stalling issue it developed last week.
ok so it's an early 1jz ge in a ex 7m powered cressida. It was working fine but it has now started stalling only after going above 80ks for a few minutes. I pull up at an intersection and it either idles really low say 2/300 rpm then stalls or just dies before I even come to a stop. Once I restart then its fine until I go above 80ks again.

So far I have checked the idle control valve. ignition timing, earthing and ecu for fault codes. next on the list is tps for correct adjustment and operation.

Anything else I am missing or should check?

[crispy'86]

Does the idle control valve run coolant through it like most of the other toyota's? May pay to check it's not blocked in the air bypass

[Jonno2002]

fkn 1jzs and their idling aye, my 1jzgte did this, i cleaned out the IACV (intake air control valve) like 3 times and that didnt fix it, then i pulled off the throttle body and cleaned that and that seemed to fix it, $&#$% knows how, either that or it was the final clean of the IACV which i did at the same time.

it still idles very low somtimes tho but never stalls, could be cause its an auto engine and ecu converted to manual who knows.

my 1ggte has a mind of its own with its idle too, sometimes high somtimes low.

just keep messing with it ull get it soon.

[whynot]

as far as I can tell it only has electronic idle control and i have had it apart and cleaned it right out so that may be a bugger. my next try is going to be the tps then i will have a look elsewhere.

I managed to keep it running when I got home and managed to get it idling at 200rpm and it slowly picked up to normal over a minute or so. dunno what that means though.

[crispy'86]

Can you get a workshop manual for the motor? Genuine toyota workshop ones like Revvy was selling seem to be the in-depth ones to consult. They have all the info on testing components in detail, Guess maybe try and see how much voltage is at the IACV with key, on engine off with a mulitmeter.
Maybe throttle body is carboned up, throttle body cleaner works wonders but strictly go off the instructions on the can.

[whynot]

I dont think it is the actual idle control valve that is the issue as it does work fine unless I go above 80k/hr. But the odd thing is this morning it went into limp home mode for 5 min then started idling fine even after driving into town at 100ks. me thinks sensor or ecu has intermittent fault and those are the worse to find. Checked with toyota and they dont have manuals in nz for the jz's as not a nz new motor.

[Jonno2002]

na u wont find an english 1jz workshop manual.

try bridging TE + E1 in the diagnostics port and checking to see if theres any error codes.

[whynot]

no fault codes in ecu. even the transmission codes come up empty. i dont think i am going to figure this one out in a hurry but It actually drivable as it is so not too worried