RB25DET Idling Terribly

[robbo_rb180]

Honestly can't remember what way as I don't have one. No it shouldn't. That solenoid should be screwed in

[Duncan]

OK a few things.

1. You need to check and set the timing. It's been a long day so just let me suggest you search in our DIY section for a thread on it. You may need to check the Link ECU to make sure but I believe an RB25 should expect 15o BTDC. There is a loop for checking timing at the rear of the engine but even better if your timing light can get a signal from the coil pack loom at cylinder 1.

2. If you have both an AAC valve and a bypass screw on the throttle body, you should be setting the idle with the AAC. So back the throttle body screw right back so it is not holding the throttle blade open, then turn the screw anti clockwise to let more air through the AAC. 

3. You mentioned you may have damaged the throttle installing the engine. Take the intake off the front of the throttle and turn the butterfly full open to closed a few times and make sure it is opening and closing smoothly, but this is unlikely to be an issue (if it was jamming it would probably jam partly open leading to more air, not less)

4. Link should be running and air intake sensor as it is MAP sensor based not AFM but that is unlikely to be the issue here unless the weather is totally different to when it was originally tuned. Also it is possible the TPS is not set properly so you should check the TPS voltage with the throttle closed.

[Eric0]

12 hours ago, Duncan said:

OK a few things.

1. You need to check and set the timing. It's been a long day so just let me suggest you search in our DIY section for a thread on it. You may need to check the Link ECU to make sure but I believe an RB25 should expect 15o BTDC. There is a loop for checking timing at the rear of the engine but even better if your timing light can get a signal from the coil pack loom at cylinder 1.

2. If you have both an AAC valve and a bypass screw on the throttle body, you should be setting the idle with the AAC. So back the throttle body screw right back so it is not holding the throttle blade open, then turn the screw anti clockwise to let more air through the AAC. 

3. You mentioned you may have damaged the throttle installing the engine. Take the intake off the front of the throttle and turn the butterfly full open to closed a few times and make sure it is opening and closing smoothly, but this is unlikely to be an issue (if it was jamming it would probably jam partly open leading to more air, not less)

4. Link should be running and air intake sensor as it is MAP sensor based not AFM but that is unlikely to be the issue here unless the weather is totally different to when it was originally tuned. Also it is possible the TPS is not set properly so you should check the TPS voltage with the throttle closed.

I have done step 1. I set the timing to 15 degrees from BTDC. I followed this diagram and set my mark on the forth for 15 degrees. It was slightly off when i started but not much. Did I do it correctly? The car still idled poorly. 
 

I accidentally moved the CAS too much to some direction and engine was idling fine. However, I want to check if I did the timing correctly based on my pictures. Thank you!

 

Edited August 9, 2020 by Eric0
Changed image

[robbo_rb180]

You need to go into the link software Pclink and change the trigger offset to set base timing and not move the CAS. I set the CAS to middle position on the bolt holes, have pclink running with timing light setup and change the offset value to get base timing to 15 degrees. The help file is very good to help with the trigger offset, if this is not done correctly on initial setup it causes issues at every step of tuning same with fuel and ignition setup as I have found a few tuners that don't understand how all the maps integrate/reference with each other. 

[Eric0]

12 hours ago, Duncan said:

OK a few things.

1. You need to check and set the timing. It's been a long day so just let me suggest you search in our DIY section for a thread on it. You may need to check the Link ECU to make sure but I believe an RB25 should expect 15o BTDC. There is a loop for checking timing at the rear of the engine but even better if your timing light can get a signal from the coil pack loom at cylinder 1.

2. If you have both an AAC valve and a bypass screw on the throttle body, you should be setting the idle with the AAC. So back the throttle body screw right back so it is not holding the throttle blade open, then turn the screw anti clockwise to let more air through the AAC. 

3. You mentioned you may have damaged the throttle installing the engine. Take the intake off the front of the throttle and turn the butterfly full open to closed a few times and make sure it is opening and closing smoothly, but this is unlikely to be an issue (if it was jamming it would probably jam partly open leading to more air, not less)

4. Link should be running and air intake sensor as it is MAP sensor based not AFM but that is unlikely to be the issue here unless the weather is totally different to when it was originally tuned. Also it is possible the TPS is not set properly so you should check the TPS voltage with the throttle closed.

For step #2 
I don’t think I have a bypass screw on my throttle body. Here are more images of my throttle body in case I missed it. 
 

I do have an AAC valve. I turned the screw slightly counter-clockwise but I didn’t notice a difference. I didn’t move it much as I wasn’t sure about the timing and want to make sure the timing is correct before moving on. 

[Eric0]

14 minutes ago, robbo_rb180 said:

You need to go into the link software Pclink and change the trigger offset to set base timing and not move the CAS. I set the CAS to middle position on the bolt holes, have pclink running with timing light setup and change the offset value to get base timing to 15 degrees. The help file is very good to help with the trigger offset, if this is not done correctly on initial setup it causes issues at every step of tuning same with fuel and ignition setup as I have found a few tuners that don't understand how all the maps integrate/reference with each other. 

All the link stuff was done at a shop so I don’t actually know how to use any of the software. 
 

I do have the link pc installed on my laptop but I don’t know how to navigate it. If you have time to inform me that would be very much appreciated! 
 

I sent my tuner a text to see if he can inform me where the timing was set before. 

[Eric0]

18 minutes ago, robbo_rb180 said:

You need to go into the link software Pclink and change the trigger offset to set base timing and not move the CAS. I set the CAS to middle position on the bolt holes, have pclink running with timing light setup and change the offset value to get base timing to 15 degrees. The help file is very good to help with the trigger offset, if this is not done correctly on initial setup it causes issues at every step of tuning same with fuel and ignition setup as I have found a few tuners that don't understand how all the maps integrate/reference with each other. 

Did my 15 degrees illustrated on the photo look okay? 

[Duncan]

Yeah the timing looks right for 15o, and the fact that it idles better with the wrong timing points to that being an issue; either Link is not set to expect 15o base, or the timing belt is a tooth off.

[GTSBoy]

11 minutes ago, Duncan said:

either Link is not set to expect 15o base, or the timing belt is a tooth off

Or the worst thing that can happen is that the outer has slipped on the pulley.

[Eric0]

1 hour ago, Duncan said:

Yeah the timing looks right for 15o, and the fact that it idles better with the wrong timing points to that being an issue; either Link is not set to expect 15o base, or the timing belt is a tooth off.

I opened the software and it looks like the timing isn’t 15 from BTDC from reading the ignition timing number 1 in the image. 
 

So, I should be setting my engine to 10 degrees? 
 

I texted my tuner and he said the ECU needs to be synchronized with the engine for proper timing (sync timing). The image shows the previous timing. I don’t know what the rest means or how to set it to that. 
 

[robbo_rb180]

43 minutes ago, Eric0 said:

I opened the software and it looks like the timing isn’t 15 from BTDC from reading the ignition timing number 1 in the image. 
 

So, I should be setting my engine to 10 degrees? 
 

I texted my tuner and he said the ECU needs to be synchronized with the engine for proper timing (sync timing). The image shows the previous timing. I don’t know what the rest means or how to set it to that. 
 

Can you send me a copy of your tune and I'll make the changes and do a step by step guide with screen shots to set it up properly. Happy to help and pass on some knowledge. 

It should be 15 degrees where 10 is. 

[Eric0]

2 minutes ago, robbo_rb180 said:

Can you send me a copy of your tune and I'll make the changes and do a step by step guide with screen shots to set it up properly. Happy to help and pass on some knowledge. 

It should be 15 degrees where 10 is. 

I’d be happy to send a copy and learn some parameter programming! Can I have your email? 
 

Is it okay to change the timing settings? Will it mess with my tune? I do plan to get the car retuned once the engine is all broken in but I want to drive it to the tuner and it’s a 3 hour drive! ;)

[Riiim6]

That image of your tune looks like that's the tools for locking your timing to 10 btdc when you're syncing your ignition timing. You should be locking your ignition timing to 15 btdc and adjusting the timing until the ignition timing on your tuner matches the ignition timing you see using your timing gun.

[Riiim6]

Also per the manual, not sure if it applies to when you're using a Link ECU, you should disconnect your TPS while syncing your timing.

[Ben C34]

9 minutes ago, Riiim6 said:

Also per the manual, not sure if it applies to when you're using a Link ECU, you should disconnect your TPS while syncing your timing.

Definitely don't need to with a link

[robbo_rb180]

 I've helped Eric get it alot better and his booked in to get his tune sorted. There is a lot of ecu set up things that weren't/still aren't perfect but can't do much from a different continent 

[Eric0]

11 minutes ago, robbo_rb180 said:

 I've helped Eric get it alot better and his booked in to get his tune sorted. There is a lot of ecu set up things that weren't/still aren't perfect but can't do much from a different continent 

 

41 minutes ago, Ben C34 said:

Definitely don't need to with a link

 

51 minutes ago, Riiim6 said:

Also per the manual, not sure if it applies to when you're using a Link ECU, you should disconnect your TPS while syncing your timing.

Yes, robbo_rb180 was helping me setup the ECU with timing and other adjustments. Now the engine idles around 700RPM. It is significantly better but now I have a tune scheduled in 4 weeks so I will update the results! 
 

Thank you all!