[dtg]

I'm getting a hesitation or pull-back at around 4700rpm, especially in 4th gear. I first noticed this on the dyno by looking at the chart showing a 10whp drop. Then I drove the car and sort of felt for it... sure enough it's definitely noticeable at 4700-5000 rpm. The car hesitates or pulls back as I'm accelerating hard in 4th gear at those rpms.

Anyone have similar issues?

[OpenFlash]

That hesitation is caused by throttle closure as can be verified by a simple OBD2 logger. It can only be fixed by retuning. If you are running a Procede, just update to the Torque Targetting demo maps posted a couple weeks ago. The resolve this issue by more accurate control of boost. This throttle closure problem occurs under many conditions but mostly during throttle transients which aren't replicated on the dyno. But if it's really bad (as it often is at ~4500rpm), it will even show up under single gear sustained dyno-like loading. You will even see it on the dyno graph as a broad dip in the power curve. Once gone, it will feel like a new car.

What tune do you have?

Shiv

[Tuned335i]

Originally Posted by shiv@vishnu

That hesitation is caused by throttle closure as can be verified by a simple OBD2 logger. It can only be fixed by retuning. You will even see it on the dyno graph as a broad dip in the power curve. Once gone, it will feel like a new car. Shiv

+1

this is the exact same thing I used to experience when running the car hard. I just updated to the new firmware & 12/15 map today and it's completely gone. Almost like a new tune was installed. Just as everyone has reported and posted videos, the engine now pulls brutally hard through the RPMs.

[dtg]

Originally Posted by Tuned335i

+1

this is the exact same thing I used to experience when running the car hard. I just updated to the new firmware & 12/15 map today and it's completely gone. Almost like a new tune was installed. Just as everyone has reported and posted videos, the engine now pulls brutally hard through the RPMs.

I'm not running the Proceed.

[scalbert]

So, what are you running so that some help might be able to be offered?

[dtg]

Originally Posted by scalbert

So, what are you running so that some help might be able to be offered?

Sorry, my bad! I'm running the jb3 with 1.11 map.

I've talked with Terry and he's been a great help and has really gone out of his way to try to solve things... even looked at the dyno files. He's sending the 1.2 update so that I can run Map 0 (stock) and see if it does the same thing...

I'm just writing on here to see if anyone else (JB3, Proceed, or stock) is experiencing a similar issue.

Shiv's reply was also helpful and sheds some insight but it is also helpful to hear from other members who have actually felt the same thing.

[cn555ic]

Thats what the new maps and firmware is suppose to take care of, the partial throttle closure that you are experiencing is what Shiv is trying to tell everyone that it takes away with Procede!

[scalbert]

Originally Posted by dtg

Sorry, my bad! I'm running the jb3 with 1.11 map.

I've talked with Terry and he's been a great help and has really gone out of his way to try to solve things... even looked at the dyno files. He's sending the 1.2 update so that I can run Map 0 (stock) and see if it does the same thing...

I'm just writing on here to see if anyone else (JB3, Proceed, or stock) is experiencing a similar issue.

Shiv's reply was also helpful and sheds some insight but it is also helpful to hear from other members who have actually felt the same thing.

Continue working with Terry to see if you can get it resolved. It is the nature of the beast with some cars experiencing it more than others.

[munters]

My guess is You will feel nothing with map 0 because the ECU will not start to "modulate the trottle" to keep the torque low. It has to be fixed in the JB map.

[Ilma]

My understanding is that there are some fuel pressure regulation issues in cold temperatures with JB3's.

The newest version 1.2 is supposed to correct this which is why Terry probably sent it.

Easiest thing to do is to wait and install it and see if the problem goes away.

If it doesn't then you may want to consider the procede!

[jgalaxy]

Originally Posted by dtg

Sorry, my bad! I'm running the jb3 with 1.11 map.

I've talked with Terry and he's been a great help and has really gone out of his way to try to solve things... even looked at the dyno files. He's sending the 1.2 update so that I can run Map 0 (stock) and see if it does the same thing...

I'm just writing on here to see if anyone else (JB3, Proceed, or stock) is experiencing a similar issue.

Shiv's reply was also helpful and sheds some insight but it is also helpful to hear from other members who have actually felt the same thing.

I suffer the same on 1.1v. 3rd, 4th (mostly) and 5th from 4200rpm up. Low or high boost map same issue. I'll test again when the 1.2 chip comes out and see if that improves things.

[RiXst3r]

Some cars get it more than others... mine had the same issue with other tunes...
but the new procede maps are a sure fix! totally gone now!

[emjei]

I am.......

[QUOTE=dtg;3852303]Sorry, my bad! I'm running the jb3 with 1.11 map.


I'm just writing on here to see if anyone else (JB3, Proceed, or stock) is experiencing a similar issue.

[Vudoo4u2]

no issues here stock

[munters]

I would say not stock and not Procede with the new maps.

[OpenFlash]

Originally Posted by munters

My guess is You will feel nothing with map 0 because the ECU will not start to "modulate the trottle" to keep the torque low. It has to be fixed in the JB map.

+1

Although based upon the design of the JB3, I'm not sure if this is feasible.

Shiv

[Mike@N54Tuning.com]

Originally Posted by scalbert

Continue working with Terry to see if you can get it resolved. It is the nature of the beast with some cars experiencing it more than others.

+1

[Mike@N54Tuning.com]

Originally Posted by shiv@vishnu

+1

Although based upon the design of the JB3, I'm not sure if this is feasible.

Shiv

Shiv, you are a great resource to the community and we all appreciate your help but you are hardly a non-bias source of information for the JB3, especially in terms of what is feasible.

The OP and anyone who has any type of technical problem should work with BMS directly to troubleshoot. Two users may think they have the same problem based on a particular symptom but most often the fix is different each time. Which is why BMS (and you) discourage public technical support. There are literally hundreds of JB3s running around problem free and no reason to believe OP won't be one of them after a little tech support.

As has been stated in the thread, the OP is working with BMS tech support to get the problem fixed and some new software is on the way so lets see what happens with that before making statements of what is possible or not. I think the OP intended this thread to see if others have this issue, so lets stay on topic

Mike

[OpenFlash]

Originally Posted by N54Tuning.com

Shiv, you are a great resource to the community and we all appreciate your help but you are hardly a non-bias source of information for the JB3, especially in terms of what is feasible.

The OP and anyone who has any type of technical problem should work with BMS directly to troubleshoot. Two users may think they have the same problem based on a particular symptom but most often the fix is different each time. Which is why BMS (and you) discourage public technical support. There are literally hundreds of JB3s running around problem free and no reason to believe OP won't be one of them after a little tech support.

As has been stated in the thread, the OP is working with BMS tech support to get the problem fixed and some new software is on the way so lets see what happens with that before making statements of what is possible or not. I think the OP intended this thread to see if others have this issue, so lets stay on topic

Mike

Mike,
The problem that the OP was describing is not isolated. The OP just knows when something is amiss whereas many others just accept drivability issues as part of the KISS (keep it simple stupid) go-fast tuning approach. Unfortunately, tuning isn't that simple when the mechanism we are tuning upon is complex. What he (and others) are describing is a common problem with most tunes (older PROcede maps included). I've done a fair bit of research into this throttle closure problem and I think I'm well versed on this topic.

I'm also well versed on the mechanism the JB3 uses to control boost. It pulls the signal to ground which means that it extends the ground pulse of the wastegate signal. This means that not only does it rely on the factory PID closed loop boost control system, it is also only capable of increasing wastegate DC, not decreasing it. And from my research on this subject, that will prevent it from solving this issue. Also, Terry has publicly stated (many times) that this throttle closure problem isn't even a problem. in fact, he describes it as desired behavior. As always, every has different tuning approaches so different strokes for different folks.

I've talked with the OP offline, as well.

Regards,
shiv

[midlife]

Originally Posted by scalbert

Continue working with Terry to see if you can get it resolved. It is the nature of the beast with some cars experiencing it more than others.

is this more a prolem with with the manual or auto, or both??

thanks

[scalbert]

Originally Posted by midlife

is this more a prolem with with the manual or auto, or both??

thanks

Seems to be more prevelant with the 6MT just after shifts. But under varying loads it can happen equally to all.

[scalbert]

I should have some hard data on a stock vehicle, JB3 1.2F and a PROcede vehicle concerning the actual throttle plate position under normal driving. Once the data is presented, people can judge for themselves. I have no clue what the outcome will be but true throttle plate position voltage versus throttle pedal voltage versus RPM should be a telling tale; if there is a tale to tell.