JZA70 wont start...problem is very very wierd

[MR 1JZ]

no kustom wiring

this thing is mint electrical wise...not a scotch lock in sight

[oldcorollas]

bugger

regarding the fires once thing...
if a coil is charged, it will release a spark when power is removed (thats how they work anyway..).. but that means if for some reason the coil is charging during cranking, and then the power to coil is cut when you turn back from cranking, then it will give a spark once (but not necessarily timed to the engine of course).....

but if it fires once at normal timing, then maybe this is not the problem, and ECU is just confused about trigger shit... or trigger sensors are rooted.. or wiring has become melted/rooted

[MR 1JZ]

yeah i gathered that much...somehow the farked ECU is sending one spark during cranking...and then stops...once we put the known good ecu on there it sends zero spark...obviously its one of the sensors...

I didnt think the map sensor controlled spark at all?
TPS sends sparking signal?
CAS does...also do the cam angle sensors send one?

Ive got a whole 1JZ filled with parts I can use to test...except TPS...

[ONETEN]

MAP & TPS has nothing to do with ignition events, think about it engine is just below atmospheric during cranking anyway. CAS is the primary engine position sensor on the 1jz, cam sensor is only for homing signal so computer can distinguish between ignition and exhaust strokes on each pair of cylinders. Considering what i have read i would be putting my money on the cas.

Easiest way to tell would be to put a noid light on an injector plug and see if they are pulsing during crank, cause if the injectors aint convulsing then the CAS aint pulsing. Especially since u have tested hengstas ecu.

[ONETEN]

Alternativly you could get the signal on a silly scope if you have one available. From memory 1jz CAS is 24 teeth so should see 24 even pulses per revolution. Then you could also look at both the cam angle sensors, only have one tooth each so if they show 1 pulse per 2 revolutions, and should see the same pulse on the opposite cam sensor on the opposite engine stroke.

Considering how crap magnetic CAS sensors are in general and especially toyota ones i would say that is prob your problem (failing fuel & spark issues).

Goodluck

[ONETEN]

1 More thing, CAS plug in engine bay is located down behind water pump, its a yellow plug from memory, check the plugs integrity first... and that its acutally plugged in :O

[MR 1JZ]

thanks hcope...ill have to track down a noid light and give it a go...

basically a test light is the same thing right?

[oldcorollas]

injector test light is an LED.. much faster reaction time than test light.. (LED and a resistor to allow it to work with the voltage you are using, ie 5V or 12V)

[MR 1JZ]

ahh fark

ok...who in SA has a noid light I can borrow?

[oldcorollas]

got a jaycar/DSE in the area?
http://forum.allaboutcircuits.com/sh...ad.php?p=75398


1K ohm 1/2 watt resistor (normal one), and any colour LED you like

[MR 1JZ]

i dont wanna make one

I wanna plug one in

[oldcorollas]

LOL, if you have wire, solder, a jet lighter and 5 seconds of time.. you can make one

or you cna probably buy one for $30.. instead of 20c....

[MR 1JZ]

oh...alright

any more than 5 seconds and you get a neg rep

[ONETEN]

yeah make yourself a jaycar LED one, but if you fail at that any mechanic worth their salt should have one the might lend...

If you wanna drive down to Sydney you can use mine.

[oldcorollas]

from dickies..
Auto Test Probe - 12V & 24V
Complete with a screw-on probe-protecting cap and alligator-clip lead, this durable metal test probe is suitable for automotive use and measurement of 12V and 24V electrical systems. An indicator globe lights when voltage is present.
Cat No. Q1539
A$9.99




edit, or this sucker.. 12V LED, $1.60 and you just solder two wires.. or spit n wrap.. or alligator clip.... or... just hold with fingers
http://www.jaycar.com.au/productView...Max=&SUBCATID=