G4+ Link ECU Timing, RB25DET

[eric240sx]

Hi everyone, 

I’m relatively new to the RB-series world and definitely new when it comes to timing an engine using G4+ link. 
 

My car was running well, and then I decided to take everything apart and powder coat it. The engine bay is looking GREAT! However, I can’t get timing right, the idle is all over the place, and it’s backfiring consistently, which I think is causing the engine to overheat as well. 
 

Timing is set at 15 degrees on g4+, but I can’t seem to be able to match that on the crank using a timing light  

Things I messed with:

1. CAS

2. TPS

3. idle control valve 

 

Things I observed:

Idle: 1,100 to 2,200 RPM, lost of misfire 

crank timing: 5 degrees 

 

How can I get the CAS (at 15 degrees), TPS, and idle control valve to be happy with each other? Any procedures? 

I’m here to learn! 

Thank you,

Eric 

[Duncan]

Well, you go to Triggers - Calibrate - Set base timing.

In that window you set whatever base timing is convenient and the ECU locks it there while you have the window open. In your case it sounds like you want to use 15o so change that if it is not, then using the timing light and adjust the CAS until it is at 15o. Be aware that it is common to get doubled readings from a timing light using the loop at the back of the engine, so you may have accidently set the base timing to 30, not 15.

Under Options there is a TPS Setup item that helps you calibrate the TPS if you think it has changed.

Even so, I am not sure that running as badly as you are saying is just a base timing issue. I guess start with that but it sounds like something else is not right.

[robbo_rb180]

Give me an hour and can do a screen grab to follow duncans guide.

Super simple to do. 
BUT don't drive it until set.

Edited October 6, 2022 by robbo_rb180
Added pictures

[robbo_rb180]

1 hour ago, Duncan said:

Even so, I am not sure that running as badly as you are saying is just a base timing issue. I guess start with that but it sounds like something else is not right.

Could have ignition idle control setup, there may be a timing offset with temp and OP said they had touched IACV so could be a bit of everything making run poorly.

[eric240sx]

7 hours ago, Duncan said:

Well, you go to Triggers - Calibrate - Set base timing.

In that window you set whatever base timing is convenient and the ECU locks it there while you have the window open. In your case it sounds like you want to use 15o so change that if it is not, then using the timing light and adjust the CAS until it is at 15o. Be aware that it is common to get doubled readings from a timing light using the loop at the back of the engine, so you may have accidently set the base timing to 30, not 15.

Under Options there is a TPS Setup item that helps you calibrate the TPS if you think it has changed.

Even so, I am not sure that running as badly as you are saying is just a base timing issue. I guess start with that but it sounds like something else is not right.

Currently, these are my timing settings on the g4+ link ECU. I'm currently using cylinder #1 with an extended spark plug cable. Does the engine need to be running to time at 15 degrees or can it be done by cranking only?

Yes, I did remove the TPS and put it back how I thought it was removed, however, idle seems to be above 1k rpm and then gets very sporadic. I read the range for the RB should be 4.5-5.2 when closed and 4.1-4.6 when WOT. Also, I did receive an error code of "ECU Fault Code 16: An Volt 3 above error value." Should I set the TPS correctly before timing to 15?

[eric240sx]

6 hours ago, robbo_rb180 said:

Could have ignition idle control setup, there may be a timing offset with temp and OP said they had touched IACV so could be a bit of everything making run poorly.

Hi Robbo_rb180! I think we have conversed on this forum before! I hope you have been well.

If it helps, I have attached my tune.

As an additional comment, the only change I made from the previous setup was change the turbo exhaust housing from .82A/R to 1.01 A/R. Could this be pushing a lot more air? Should I just schedule a tune?

So far,

1. Recalibrate TPS 

2. Timing is already set at 15 degrees, offset -86 (what does this parameter mean?), does engine need to be running or can it be done while cranking only?

RB25DET_SETUP.pclr

[Duncan]

So firstly, while I have a link in the Stagea, I'm no expert, and the software is almost as bad as the Haltech plug in software so it is a bit of a challenge.

I am not sure that there is an order required between TPS calibration and timing. There is on the standard ECU but since you can lock timing in the Link I guess you can do either order.

The TPS raw voltage doesn't really matter, what matters is the Link knows the closed and WOT voltage, so I'd do that calibration process first.

The timing is locked when that timing screen is open, so make sure it is open when you are trying to set the base timing. I've only ever done it by getting the CAS into the ballpark (if it's marked) or starting at the middle of adjustment, starting the engine and then adjusting to get to the target (15o in your case). It may be possible to do when cranking.

And yes, absolutely you need to return after changing the turbo. Same boost but bigger housing is more air which will require more tune. However, off boost at idle it should not make a material difference so that is not your issue.

I should add, you need to make sure you don't have a mechanical issue like an air leak before chasing ECU issues. An air leak is the most likely cause of a high idle.

[robbo_rb180]

@eric240sx we have was a while ago.

To get the offset 100% right car needs to be running But get get ballpark as Duncan said justcat cranking. You add or subtract from the current -86 offset. I usually add 5 first time to see which way offset needs to go. Can easily see it on the balancer marks if you can't see the marks timing is way out.

Ensure that there are no leaks in manifold, throttle body, iacv.

Check all the grounds are attached from block to chassis and the one from the loom to the plenum is clean. Battery is charged.

When checking the timing don't use the loop wire. Get an ignition lead to go between coil and spark plug and clip the reference lead on there. 

Will need a retune with the bigger housing but I  can setup a lambda table  so can do quick tune with it so can drive it to the tuner.

[eric240sx]

1 hour ago, Duncan said:

So firstly, while I have a link in the Stagea, I'm no expert, and the software is almost as bad as the Haltech plug in software so it is a bit of a challenge.

I am not sure that there is an order required between TPS calibration and timing. There is on the standard ECU but since you can lock timing in the Link I guess you can do either order.

The TPS raw voltage doesn't really matter, what matters is the Link knows the closed and WOT voltage, so I'd do that calibration process first.

The timing is locked when that timing screen is open, so make sure it is open when you are trying to set the base timing. I've only ever done it by getting the CAS into the ballpark (if it's marked) or starting at the middle of adjustment, starting the engine and then adjusting to get to the target (15o in your case). It may be possible to do when cranking.

And yes, absolutely you need to return after changing the turbo. Same boost but bigger housing is more air which will require more tune. However, off boost at idle it should not make a material difference so that is not your issue.

I should add, you need to make sure you don't have a mechanical issue like an air leak before chasing ECU issues. An air leak is the most likely cause of a high idle.

Thank you Duncan for sharing, I have a list of things I will try after work and will report back the state of the car by the end of the day. 

1. TPS Calibration 

2. Timing 

3. Checking for leaks 

I have also rescheduled a tune for Novemember. 

[eric240sx]

30 minutes ago, robbo_rb180 said:

@eric240sx we have was a while ago.

To get the offset 100% right car needs to be running But get get ballpark as Duncan said justcat cranking. You add or subtract from the current -86 offset. I usually add 5 first time to see which way offset needs to go. Can easily see it on the balancer marks if you can't see the marks timing is way out.

Ensure that there are no leaks in manifold, throttle body, iacv.

Check all the grounds are attached from block to chassis and the one from the loom to the plenum is clean. Battery is charged.

When checking the timing don't use the loop wire. Get an ignition lead to go between coil and spark plug and clip the reference lead on there. 

Will need a retune with the bigger housing but I  can setup a lambda table  so can do quick tune with it so can drive it to the tuner.

Woah! Between you and Duncan I feel like I can do anything, haha! Perfect, I will report back. Thank you

[eric240sx]

9 hours ago, Duncan said:

So firstly, while I have a link in the Stagea, I'm no expert, and the software is almost as bad as the Haltech plug in software so it is a bit of a challenge.

I am not sure that there is an order required between TPS calibration and timing. There is on the standard ECU but since you can lock timing in the Link I guess you can do either order.

The TPS raw voltage doesn't really matter, what matters is the Link knows the closed and WOT voltage, so I'd do that calibration process first.

The timing is locked when that timing screen is open, so make sure it is open when you are trying to set the base timing. I've only ever done it by getting the CAS into the ballpark (if it's marked) or starting at the middle of adjustment, starting the engine and then adjusting to get to the target (15o in your case). It may be possible to do when cranking.

And yes, absolutely you need to return after changing the turbo. Same boost but bigger housing is more air which will require more tune. However, off boost at idle it should not make a material difference so that is not your issue.

I should add, you need to make sure you don't have a mechanical issue like an air leak before chasing ECU issues. An air leak is the most likely cause of a high idle.

 

8 hours ago, robbo_rb180 said:

@eric240sx we have was a while ago.

To get the offset 100% right car needs to be running But get get ballpark as Duncan said justcat cranking. You add or subtract from the current -86 offset. I usually add 5 first time to see which way offset needs to go. Can easily see it on the balancer marks if you can't see the marks timing is way out.

Ensure that there are no leaks in manifold, throttle body, iacv.

Check all the grounds are attached from block to chassis and the one from the loom to the plenum is clean. Battery is charged.

When checking the timing don't use the loop wire. Get an ignition lead to go between coil and spark plug and clip the reference lead on there. 

Will need a retune with the bigger housing but I  can setup a lambda table  so can do quick tune with it so can drive it to the tuner.

Hi Duncan and Robbo,

 

Okay, I have done the following:

1. Calibrated TPS successfully, I noticed the throttle percentage was at 5% originally, but is now at 0% when closed and 100% when fully opened. 

2. Set timing to 15 while cranking, turned the engine on, had to move -86 offset to -80 to read 15 across all RPM range, I would say timing now looks good! The car also seems to stay consistently at 180-190 degrees. Doesn’t seem to overheat anymore. 

3. After setting TPS and timing, I did notice the idle start fluctuating from 1,300-2,300 RPM over and over. Like Duncan said, could be a vacuum leak. How do I locate vacuum leaks? Someone said to use a smoke machine, any other things to check? Seems like the issue now is erratic idle. Could intercooler leaks also cause the pulsating idle? Or a sensor, maybe the idle control valve? Anything to check on g4+?

 

 

Thank you! 

 

[Duncan]

Glad you've made some progress. Apart from visual inspection of the main hoses, you could spray a little start ya bastard/ether/brake cleaner on any suspect joints; if idle rises you know the extra fuel made it to the inlet so there is a leak there. They can be hard to find though.

I'm not familiar with idle control on rb25, but what did you do to that valve, just clean it?  You might need to reset an idle screw if it has gone form dirty to clean

[eric240sx]

4 minutes ago, Duncan said:

Glad you've made some progress. Apart from visual inspection of the main hoses, you could spray a little start ya bastard/ether/brake cleaner on any suspect joints; if idle rises you know the extra fuel made it to the inlet so there is a leak there. They can be hard to find though.

I'm not familiar with idle control on rb25, but what did you do to that valve, just clean it?  You might need to reset an idle screw if it has gone form dirty to clean

Thank you! It was a little intimidating but I can officially rule TPS and timing out until the tune. 
 

A stable idle is what I’m looking for now. “Start ya bastard” is hilarious!
I’ll give that a go tomorrow. 
 

I also torqued my intake manifold from Greddy to 14ft/lbs or 19Nm. A little over manufacturer spec since it’s an aftermarket intake.

For the idle control valve, I took it apart and cleaned it. Maybe I didn’t assemble correctly? I would think the idle control valve either makes an idle lower or higher but doesn’t actually cause erratic RPMs. But I’m not sure. 
 

I will also be double checking connections tomorrow. 

[eric240sx]

Just now, eric240sx said:

Thank you! It was a little intimidating but I can officially rule TPS and timing out until the tune. 
 

A stable idle is what I’m looking for now. “Start ya bastard” is hilarious!
I’ll give that a go tomorrow. 
 

I also torqued my intake manifold from Greddy to 14ft/lbs or 19Nm. A little over manufacturer spec since it’s an aftermarket intake.

For the idle control valve, I took it apart and cleaned it. Maybe I didn’t assemble correctly? I would think the idle control valve either makes an idle lower or higher but doesn’t actually cause erratic RPMs. But I’m not sure. 
 

I will also be double checking connections tomorrow. 

Adding a picture of the idle control valve for reference 

[Duncan]

The idle control can absolutely cause erratic high idle. The ECU is targetting whatever it was told, say 800rpm and will see it is high. Since it can't control air volume it tries to control fuel, so it would pull fuel out until it gets near the target, at which point it returns to the map which might cause the idle to spike again because there is more air than expected.

That looks like the same AAC as I have on the Stagea, there should be a large screw in the end not shown in the pic. Wind it in until snug and see if it idles, if not back it out a little until you get the idle you are after.

[robbo_rb180]

The idle target is set too high in the tune 1300rpm and alidle day cycle is too high.

When I am home tomorrow I'll modify a tune and send it to you then log it and we will get you sorted.

Good work getting tps and timing done. Ecu wouldn't have been meeting idle conditions. 

[Ben C34]

On 10/7/2022 at 6:18 PM, Duncan said:

, so it would pull fuel out until it gets near the target,

Ecus dont control idle speed with fuel, it is  ignition first then airflow.

[eric240sx]

13 hours ago, Duncan said:

The idle control can absolutely cause erratic high idle. The ECU is targetting whatever it was told, say 800rpm and will see it is high. Since it can't control air volume it tries to control fuel, so it would pull fuel out until it gets near the target, at which point it returns to the map which might cause the idle to spike again because there is more air than expected.

That looks like the same AAC as I have on the Stagea, there should be a large screw in the end not shown in the pic. Wind it in until snug and see if it idles, if not back it out a little until you get the idle you are after.

 

12 hours ago, robbo_rb180 said:

The idle target is set too high in the tune 1300rpm and alidle day cycle is too high.

When I am home tomorrow I'll modify a tune and send it to you then log it and we will get you sorted.

Good work getting tps and timing done. Ecu wouldn't have been meeting idle conditions. 

 

10 hours ago, Ben C34 said:

Ecus dont control idle speed with fuel, it is  ignition first then airflow.

Hi all,

 

I have a guy coming in tomorrow to do a smoke test. Through the research I did, a smoke test will find every leak imaginable if there is any. 
 

Hi Robbo, yes, I thought the target idle was WAY too high. Hopefully we can get the tune happy enough to drive it to a tune shop. It’s a different guy this time. 

[eric240sx]

On 10/7/2022 at 12:48 AM, Duncan said:

The idle control can absolutely cause erratic high idle. The ECU is targetting whatever it was told, say 800rpm and will see it is high. Since it can't control air volume it tries to control fuel, so it would pull fuel out until it gets near the target, at which point it returns to the map which might cause the idle to spike again because there is more air than expected.

That looks like the same AAC as I have on the Stagea, there should be a large screw in the end not shown in the pic. Wind it in until snug and see if it idles, if not back it out a little until you get the idle you are after.

 

On 10/7/2022 at 1:43 AM, robbo_rb180 said:

The idle target is set too high in the tune 1300rpm and alidle day cycle is too high.

When I am home tomorrow I'll modify a tune and send it to you then log it and we will get you sorted.

Good work getting tps and timing done. Ecu wouldn't have been meeting idle conditions. 

 

On 10/7/2022 at 3:09 AM, Ben C34 said:

Ecus dont control idle speed with fuel, it is  ignition first then airflow.

Hi Everyone,

Up to date status:

I checked for leaks using a smoke detector. I started by inserting smoke from the turbo intake side, held my throttle body open, and let the pressured (6psi) smoke fill my entire system. There were absolutely no leaks of any kind. 

I cranked the engine and set it to 15 degrees, then I started the engine and set it at 15 degrees (when cold it doesn't fluctuate), but when it warms up enough, it starts idling from 1,300 up to 2,500 RPM. I also noticed the timing moves with the idle. Maybe the timing isnt set and locked properly?

How I set timing:

1. Unpluged TPS

2. Cranked engine without starting until CAS lines up with 15 degrees 

3. Plugged TPS back in

4. Turned engine on (has high idle of 2,000rpm)

5. Adjusted timing offset on g4+ to read 15 on timing mark (still high idle)

6. Engine idle starts fluctuating and timing ranges from 10-25. Idle goes down as it approaches 10, idle goes up as it approches 25. 

I'm not sure how to stop the erradic timing or is it supposed to be that way? Or does that stem from another problem?

[Duncan]

Have you tried to adjust the airflow at idle by turning the big screw on the AAC? As you've cleaned it, it may be letting significantly more air through than when the the ECU was tuned