RB26 idle and driving problem

[ATpossible]

I hate to do this, but I recently got my car, 1996 240sx with an RB26DETT and I have no idea what is wrong with the car or how to check it at the moment. I'm hoping you guys can help. Stock ecu, injectors, coil packs

Symptoms:
The car idles rough and fluctuates from as high as 2k rpm to almost dying, but it never dies. The tach might not be showing the right reading anyway but I clearly have a problem. A technician first thought it might be a misfire from the sound and riding in the car. He checked the injectors and coil packs with a stethoscope and said they sounded fine.

The car also drives extremely rough like sputtering or like the engine is having a hard time accelerating. Maybe similar feeling like a misfire? Sorry for layman terms

I did some reading and I keep seeing ignition being brought up like the ignitor chip. Can you guys give me logical steps to take to check the car for the likely problem(s)?

Thanks in advance.

[Krazykouki]

Idle problems are common with RB's and it is normally something as simple as a dirty MAF, fouled plugs or improper wiring. Here is a link to the FSM's, download the one that pertains to your year engine and start investigating. Post up results.

http://www.nicoclub.com/FSM/rb/

1. Check battery voltage at idle as soon as you start it

2. Check grounds

3. Check for ECU codes

4. What is the Vacuum reading at idle?

5. Use the FSM to check the coil packs for proper resistance

6. Make sure the TPS is calibrated correctly

7. Make sure your MAF's are clean

8. Make sure the Idle Air Control Valve is clean and working properly as well

9. Use the FSM to properly adjust the idle air screw if none of the above help

10. Make sure that you have NO boost leaks, do a pressure test if you are unable to find anything visually

11. Use the FSM to check the ignitor chip

12. Make sure your plugs are not fouled

[Ramius83]

Check Base Timing with TPS unplugged, check TPS sensor readings with throttle closed and when fully open. Two basic EASY checks that would cause an erratic idle, usually....

[ATpossible]

Check Base Timing with TPS unplugged, check TPS sensor readings with throttle closed and when fully open. Two basic EASY checks that would cause an erratic idle, usually....

Will do that. Thanks for advice

[ATpossible]

Idle problems are common with RB's and it is normally something as simple as a dirty MAF, fouled plugs or improper wiring. Here is a link to the FSM's, download the one that pertains to your year engine and start investigating. Post up results.

http://www.nicoclub.com/FSM/rb/

1. Check battery voltage at idle as soon as you start it

2. Check grounds

3. Check for ECU codes

4. What is the Vacuum reading at idle?

5. Use the FSM to check the coil packs for proper resistance

6. Make sure the TPS is calibrated correctly

7. Make sure your MAF's are clean

8. Make sure the Idle Air Control Valve is clean and working properly as well

9. Use the FSM to properly adjust the idle air screw if none of the above help

10. Make sure that you have NO boost leaks, do a pressure test if you are unable to find anything visually

11. Use the FSM to check the ignitor chip

12. Make sure your plugs are not fouled

Not sure where I would even begin with the FSM. I have one said on my computer, but the wiring portion of the FSM was minimal and poor quality anyway.

However I will work through your list of suggestions and post my findings. Thanks for your help

[Krazykouki]

the wiring..this should help some:

http://media.sxoc.com/contributors/s14f ... Jan_10.pdf