Possible bs3 issue?

[LTLHOMER]

Near the top of first gear (haven't got a chance to try 2nd/3rd yet), the map sensor goes from reading around 10-12 lbs of boost and pulling fine to all of a sudden reading 27 lbs and then adding 27 lbs worth of fuel. I ran some tests on the map sensor when I got home and it reads fine all the way from atmospheric to 3 bar absolute and everywhere in between (even tried shaking it to try and mimic any possible vibrations and what not). Could this be something in the big stuff 3 box itself? I have had some issues with this box before and had to get it repaired is there a chance it's just cursed or something? It's impossible to tune the car when the ecu can't even get correct readings and if those are correct, what is going on? It's definitly not moving 27 lbs of air so is it possible that it's back-firing through the intake and causing the map to read that and then add fuel? Or could my coilpacks not be up to snuff and need upgrading? I am not sure what to do as trying to tune the car with this issue doesn't seem to be doing any good.

Any ideas Sparky and friends? I'm going to give John a call Monday and see if I can send my box back and have him look at it but if the box is fine, what else is there?

[Sparky]

Are you having any type of misfire issues? If your experiencing possible coil break down and/or misfire, this could very well cause inaccurate readings within the MAP.
I would like to forward this post on to Don Baliey. I know when you posted some issues before I mentioned passing your info onto Don. How did this work out?
I don’t think the ECU would just throw false fuel without some type of signal input.

From an installation stand point, are all of your Grounds on the same playing field? John is pretty adamant about the whole Grounding deal. 99% of all misfires are Ground related.

Sparky

[LTLHOMER]

My post didn't go through or something...so I'll try to summarize.

I've talked with Don a few times and he's been helpful. I will send him the logs as soon as Rich gets a chance to send them to me since they were logged on his laptop. And I am going to make a trip to Chicago as soon as we get the car close because Don is really good with getting drivability type things as well as fine-tuning the car to get the most out of it. I just don't want to bring the car down with it having weird issues since that'll just waste his time and my time and money. But I will for sure be down there as soon as I can.

What grounds do I need to check? The coilpacks are grounded to the cylinder head which is grounded through the front and mid motor plates. Any other important ones? I can try running an additional ground strap from the motor to the chassis if you think that would help.

[LTLHOMER]

Also Sparky...is there a way I can get my box upgraded or something so I can have some additional inputs for the bs3 to record? It's got the internal data-logging, but I want to be able to monitor fuel and oil pressure, as well as hooking up another map sensor to compare the back of the elbow readings vs the ones on the side.

Is that possible?

[Sparky]

If you add the External Logger which includes Oil Pressure, Fuel Pressure, Turbo Back Pressure, Pan Vac, Drive Shaft Speed, Input Shaft Speed and Turbine Shaft Speed, this would help get the extra signals you are looking for. You don’t have to use all the signals, you could use only the ones you would need.
The Box would need to be updated with the External Logger Signals and there’s another Harness for the External Logger items.

As far as the Grounds are concerned, you should have the Battery Power and Ground on the Battery, more importantly the Ground on the Battery. I am assuming there is an On/Off Switch involved, which makes getting on the Power side of the Battery a bit tougher. So the Ground should definitely be on the Negative side of the Battery.

Thank you for your feedback with Don Baliey. Don brings a lot to the table when it comes to tuning issues and concerns.

I hope this helps,
Sparky

[LTLHOMER]

Ground from bs3 is right to the battery itself. Power from the bs3 goes to the battery side of the cutoff switch. I could move it to the actual battery if necessary since the bs3 needs a switched 12v to turn on anyways.

How much does it cost to get that external sensor option added? And can I do that through you or is that something I need to talk to Meaney himself about? Does the upgrade let me monitor 3 additional pressure sensors? I want to monitor oil pressure, fuel pressure, and add an additional manifold pressure sensor to compare the readings on the side of the elbow vs the back to see if that might have been the problem.

Thanks for your help Spark!

[Sparky]

If you’d like me to take care of it with John for you, I'm only about 15 minutes from John, so it wouldn’t be a problem. I don't know what it would cost to add the external Logger, but I will check on it tomorrow for you and let you know.

If you don't use the Turbo Back Pressure signal, it wouldn’t be a problem to use this signal as an additional MAP sensor at the Elbow. It will still be labeled as Turbo Back Pressure in the log, you just have to make a mental note that this signal is an additional MAP sensor signal.

Another signal that is growing in popularity is a pressure sensor in the cooling system (radiator or intake), monitoring this signal helps to let you know when you have lost a Head Gasket.

Just some food for thought,
Sparky

[LTLHOMER]

Sparky,

Yeah see what you can find out and we can go from there. The racing budget has been depleting steady but this is something I 100% need so it's just a matter of when I can get it not if I can get it. I wanted to send my box to John to get looked at anyways to rule that out as a potential problem so this way I can kill two birds with one stone. Let me know what you find out and give me a call anytime at 586 634 7177. I am up between 9am and 3am so anytime between then works. Or just PM me on here as I am usually around a computer.

Thanks for your time,
Sean

[Six_Shooter]

Just out of curiosity and seeing this happen to other people:.....

You're 110% sure this is not a mechanical issue?

You say it's at the top of first, meaning that you'd be at or near redline, possibly getting into valve float or possibly getting to a point where intake reversion happens, though I haven't heard of anything this severe.

What about your BOV? Is it possibly adjusted or hokked up in such a way that it may be open and leaking and that at higher RPM, it actually closes sending a momentary spike of intake pressure into the engine and being picked up by the MAP sensor?

Just thoughts.

[LTLHOMER]

Just out of curiosity and seeing this happen to other people:.....

You're 110% sure this is not a mechanical issue?

You say it's at the top of first, meaning that you'd be at or near redline, possibly getting into valve float or possibly getting to a point where intake reversion happens, though I haven't heard of anything this severe.

What about your BOV? Is it possibly adjusted or hokked up in such a way that it may be open and leaking and that at higher RPM, it actually closes sending a momentary spike of intake pressure into the engine and being picked up by the MAP sensor?

Just thoughts.

Not 100% sure of anything...I doubt it's valvefloat since it's a solid roller and even good hydraulic rollers can spin 7k without much issue...this happens around 6700-6800 and 'redline' isn't until at least 8k. Intake reversion would be a possibility but this cam was used in an almost identical combo (same compression ratio, intake, turbo kit, cubes, similar heads, etc) without that kind of issue.

I still have to check the wg's and bov's to make sure nothing weird is going on there. I'll check those soon and hopefully rule that out...

Plan of action thus far is to change the coilpacks to the better truck ones, move the sensors to the side of the elbow, and get the other inputs for the bs3 since they are important to have even if I wasn't having any problems.