1jz running bad - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

dakotawelch21 · 04-09-2018, 06:03 PM

After swapping a 1jz into my 240sx I've had issues with the motor. Compression tested fine with all cylinders around 155. Once I start it the engine will run good until it is switched over to open loop the car runs bad. When trying to rev it up there is sudden jolts of power and is not smooth at all. The idle seems a little higher and has many hiccups in it. I've already changed O2, MAP, Crank position, cam position, and throttle position sensor. None of those sensors have changed anything. Yes I did set my TPS when installing it.

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di-devol · 04-10-2018, 10:08 AM

Quote:

Originally Posted by dakotawelch21

After swapping a 1jz into my 240sx I've had issues with the motor. Compression tested fine with all cylinders around 155. Once I start it the engine will run good until it is switched over to open loop the car runs bad. When trying to rev it up there is sudden jolts of power and is not smooth at all. The idle seems a little higher and has many hiccups in it. I've already changed O2, MAP, Crank position, cam position, and throttle position sensor. None of those sensors have changed anything. Yes I did set my TPS when installing it.

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Any codes? What wiring? non-vvti? ECU good?

I had a bad ecu on mine, leaky capacitors.

dakotawelch21 · 04-10-2018, 10:23 AM

Quote:

Originally Posted by di-devol

Any codes? What wiring? non-vvti? ECU good?

I had a bad ecu on mine, leaky capacitors.

No codes and I wired the motor by myself. Earley I had the car running fine so I doubt it is the wiring although it could be. It is a non-vvti. I have replaced the ecu with a buddy of mines and nothing has changed.

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coBBz · 04-10-2018, 10:42 AM

Could be the igniter chip acting up, or something in your piping stopping airflow like mine was lol

dakotawelch21 · 04-10-2018, 11:02 AM

Quote:

Originally Posted by coBBz

Could be the igniter chip acting up, or something in your piping stopping airflow like mine was lol

I will check when I get home. I also have a spare ignitor that I have tried that didn't change anything.

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heywier427 · 04-10-2018, 11:48 AM

If you unplug the o2 sensor, does it say in open loop and run fine?

I think you meant to say, goes to closed loop.

di-devol · 04-10-2018, 11:50 AM

Bad coolant sensor?

Funny you don't have any codes.

dakotawelch21 · 04-10-2018, 12:26 PM

Quote:

Originally Posted by heywier427

If you unplug the o2 sensor, does it say in open loop and run fine?

I think you meant to say, goes to closed loop.

Yes thank you I meant closed loop. I will try to unplug my O2 sensor and see what it does. Thank you guys for the input

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heywier427 · 04-10-2018, 01:18 PM

No codes is weird. I would think if bad coolant temp sensor, the ecu would never go into closed loop. As its not seeing that requirement set.

I know nothing about the jz. Coil / coilpacks not functioning correctly when hot?

Thats seen more on a old style coil than coil packs/plug on coil.

Does the jz ecu allow you to plug in and read realtime data?

04-09-2018, 06:03 PM	#1
dakotawelch21 Join Date: Apr 2018 Location: US Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	1jz running bad After swapping a 1jz into my 240sx I've had issues with the motor. Compression tested fine with all cylinders around 155. Once I start it the engine will run good until it is switched over to open loop the car runs bad. When trying to rev it up there is sudden jolts of power and is not smooth at all. The idle seems a little higher and has many hiccups in it. I've already changed O2, MAP, Crank position, cam position, and throttle position sensor. None of those sensors have changed anything. Yes I did set my TPS when installing it. Sent from my SM-G950U using Tapatalk

04-10-2018, 11:50 AM	#7
di-devol Zilvia FREAK! Join Date: Jun 2010 Location: Woodinville Age: 39 Posts: 1,412 Trader Rating: (5) Feedback Score: 5 reviews	Bad coolant sensor? Funny you don't have any codes. __________________

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04-10-2018, 10:42 AM	#4
coBBz Zilvia Member Join Date: Jun 2016 Location: California Age: 26 Posts: 166 Trader Rating: (3) Feedback Score: 3 reviews	Could be the igniter chip acting up, or something in your piping stopping airflow like mine was lol

04-10-2018, 11:48 AM	#6
heywier427 Join Date: Aug 2017 Location: CT Coast Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	If you unplug the o2 sensor, does it say in open loop and run fine? I think you meant to say, goes to closed loop.

04-10-2018, 01:18 PM	#9
heywier427 Join Date: Aug 2017 Location: CT Coast Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	No codes is weird. I would think if bad coolant temp sensor, the ecu would never go into closed loop. As its not seeing that requirement set. I know nothing about the jz. Coil / coilpacks not functioning correctly when hot? Thats seen more on a old style coil than coil packs/plug on coil. Does the jz ecu allow you to plug in and read realtime data?