1jz cold start problem

[chaserbuddy]

hey

I have a 1jz out of a jzx90 fitted into an mx83 and it has trouble starting in the mornings or when cold. I have noticed that the colder the weather is the harder it is to start. It turns over fine and will eventually start and splutter for a few seconds and then die, Also as soon as I press the accelerator it will kill it. I have to start it up again and leave it idling for a while and the rpm will eventually rise up from around 500 as it gets warmer. Generally it takes a couple of minutes for it to warm up enough to drive. Once its warmed up there are no problems at all and it runs fine. Things I have done so far are check that the fuel is priming which it is, cleaned the iscv, replaced the water temp sensor for the ecu, replaced the air temp sensor. and pulled codes, 1, 2 twice(not sure if that means 22 or 2 as it flashes twice with a 2.5sec pause and then another two times),4,7 and 8.

If anyone has any idea of what may be wrong with it please let me know.

Also if anyone has a auto jzz30 or jzx90 ecu that I could try to help eliminate the ecu as the problem that would be great.

Thanks

[midnight_purple_GA70]

I think i have a jzx90 ecu but am not sure... definately some variant of 1jz auto ecu...

is the IACV actually opening on startup?

[chaserbuddy]

I think i have a jzx90 ecu but am not sure... definately some variant of 1jz auto ecu...

is the IACV actually opening on startup?

there is power to it, so i assume its doing its job, I did swap it over from a running 1jz so it's probably not that. Hopefully someone has one locally so I can check rather than having to purchase one from interstate. I'll let you know if I require it thanks.

[JP]

What heat range are the plugs that are installed?

A 1J I got from japan once had a set of cold HKS plugs in it which started OK in summer in Brisbane, but once it got to winter it was a real pain to cold-start. Replaced them with Denso PK20R11's and it started fine when cold.

[chaserbuddy]

What heat range are the plugs that are installed?

A 1J I got from japan once had a set of cold HKS plugs in it which started OK in summer in Brisbane, but once it got to winter it was a real pain to cold-start. Replaced them with Denso PK20R11's and it started fine when cold.

I'll look at that, haven't looked at the spark plugs yet, Also I sprayed some start ya bastard into the intake and it fired first shot and then died once the vapors were used up. I'm really not too sure whats happening it seems as though the ecu isn't putting enough fuel in on cold start. thanks for your input

[midnight_purple_GA70]

there is power to it, so i assume its doing its job, I did swap it over from a running 1jz so it's probably not that. Hopefully someone has one locally so I can check rather than having to purchase one from interstate. I'll let you know if I require it thanks.

try disconnecting the breather hose off the back of it and blocking off the turbo side...

you will hear a very loud suction noise from the IACV if it works if you dont then somewhere in the wiring a fault has come about... or a sensor is playing up with something etc...

[wilbo666]

First think I'd be doing is sorting out the check engine codes

Is it possible that you may have codes 22, 24 and 78?

22 = Water Temp Sensor
24 = Air Temp Sensor
78 = Fuel Pump Control

I'd be checking the resistance values of the Water Temp Sensor and the Air Temp Sensor at the engine ECU plugs with the engine ECU unplugged to make sure the wiring in the loom and the sensors are OK

Cheers
Wilbo

[chaserbuddy]

First think I'd be doing is sorting out the check engine codes

Is it possible that you may have codes 22, 24 and 78?

22 = Water Temp Sensor
24 = Air Temp Sensor
78 = Fuel Pump Control

I'd be checking the resistance values of the Water Temp Sensor and the Air Temp Sensor at the engine ECU plugs with the engine ECU unplugged to make sure the wiring in the loom and the sensors are OK

Cheers
Wilbo

I suppose it is possible, As I haven't had much experience in checking codes. thanks Wilbo I will check the sensors and wiring again.

[chaserbuddy]

had a look at the wiring again and I noticed that someone had wired the temperature gauge off the water temperature input to the ecu also having known that the dash temp gauge has its own thermostat the wiring was incorrect. Makes sense as the current and voltage to the ecu will have been reduced and therefore changed the predicted water temperature. Problem is now fixed. thanks for everyone that contributed.

You must spread some Reputation around before giving it to wilbo666 again.

[wilbo666]

Good to hear you fixed it!

Cheers
Wilbo

[Hengsta]

That would of been me!

My bad, glad you fixed it mate. All running now?

[chaserbuddy]

That would of been me!

My bad, glad you fixed it mate. All running now?

yeah no problems now, starts first go every time and runs well.