1jz sc300 swap idle/drive problem

[armyastro]

i just got done with my swap and it start and the idle goes up and down and then kinda evens out. if i try to drive it it bucks and kicks and backfires and such. i have been looking for the 12v mod but you cant search for stuff with 3 letter words. i am lost and cant figure it out. does anybody have any ideas that might help. thanks

[armyastro]

there is a 3 wire plug on the harness right behind the intake mani next to the 2 wire plug for the heater valve... i think the shop may have left off the map/turbo pressure sensor and they are not open to get it. i also cant find it so that is what i beleive happened.... but would the car even start without it...??? please someone give me theyre 2 sense.. thanks

[armyastro]

yeah after alot of looking i have found it is gone and the shop is closed... i had one from the mk3 7mgte that i have... is it the same cause it snaps in??? thanks

[gonesingle]

Ask for your $$ back for the swap, they are idiots. The 3 wire plug next to the 2 wire heater VSV is for the MAP sensor. If they don't have it or "lost it", 1JZ MAP's are hard to come by and expect to pay 50-100$ for a used one. I'll sell you my spare for $100 shipped and tested on my car. It's off a supra 1JZ and looks different, but works just the same.

You can try the 7MGTE MAP, but it's known to not work. There is no american cross reference for the map sensor.


The fuel ECU is behind the drivers side rear passenger panel under the sail window. Remove the rear seat and the panel unclips. Unplug the plug to the fuel ecu and solder the two big wires together. Done.

[armyastro]

ok i got a 2jz map and hooked it up and it is the same thing but just alittle better.... it is idling badly and it misses alot.... i can unplug the coils one by one or even the injectors and it is like they are not working??? i will try the 12v mod and see and hopefully that will work... if not then i guess it is the 2jz map sensor... please someone confirm the map sensor thing... thanks

[gonesingle]

2jz map sensor makes it run richer. You probably just have a bad ecu like everyone gets at one point, or another

[armyastro]

i have another ecu let me try it

[armyastro]

nope ecu did not work
the coils seem to be not firing when they should...

[gonesingle]

shouldnt the shop you paid to install this have fixed this problem?

[armyastro]

no i asked them to put the engine in and run the wring harness for me... i dont have a lift or hoist and they are good friends
they did my 5 speed swap too and are very good people but they just installed for me and that is it...i checked continuity from injectors to ecu and ignitor to ecu then from ignitor to coils... all is good and the seperate wires on the inj and coils have 4 ohms between it and ground with key on and 11 with key off... i think maybe the coils are shot they have rust and stuff on them and had water around the plugs when bought. and there is a crack or two on the part that goes to the plug... but it stutters really bad when you try to drive it..

[Kaiser]

Are we using new spark plugs? Please say yes. Also, if the plug boot has a rip in it then the spark could be arching to the head.

[armyastro]

new ngk's and the boot is fine .. the coil has a crack in it... i know that could cause alittle of it but it is crazy bad.. like the timing goes haywire and it looses all power then starts sputtering and backfires

[Kaiser]

Try a different O2 sensor yet?

[armyastro]

o2 sensors dont work until it heats up to operating temp and goes closed loop i believe

[Bean]

what about timing and/or knock sensors

[armyastro]

ok fixed it all and it PULLS HARD love it and should have swapped along time ago.. thanks everyone for the help and FAST part shipping... it was coils, iacv, mas and plugs again.... lol but it if sine and great now...