Dave, was this code P1235?

 

NOTE * this is based upon my opinion not facts

I feel it is not a boost problem as we have turned our boost up all the way and gotten many over boost cel's without limp mode

Its an AIR FLOW / TQ issue

As I stated above if the car is making more TQ than the throttle mapping is looking for it will through a CEL which is apparently a LIMP mode

Once you start adding all the Buschur parts you start to reallty get a lot more TQ and this is what is causing the problem

Ecutek will be out very shortly and this problem will just be a matter of adjusting a few maps

AMS got around the problem by using a piggy back which cuts the amount of air flow reported so the ecu is tricked into think its making less power - another effective way to solve the problem but less elegant

 

I have a similar issue with my car but its not a TPS code its an o2 sensor code. With stock exhaust but with the boost controller installed, it would come on if I ran full boost at partial throttle. Says rear bank o2 sensor or something like that

-Steve

 

Yea SRT's go into limp mode as well .. it's good if you think about it .. **** won't blow up if something goes wrong ..

 

exactly, if you are going to run a huge spike I have a feeling you will get inconsistent PTB and when you have 19-20PSI and your only getting fuel mapped for maybe 12PSi you are really chancing your motor.
Wait for a proper way to tune it.

 

Well of course we all want all that boost whenever but ask yourself the question is it safe for the motor?
Granted we dont cruise around at 70%throttle for a prolonged amount of time but 19PSI with a AFR of 14.something does not sound like a good idea.
IF you arent tuning the fuel (which you stated above) I would think it highly unlikely that the motor and ecu is compensating for these conditions.
Your WOT situation may be safe but I would bet your PT situations are not nominal.
All it took with the SRT was 1psi to be off somewhere and you would go to limp if you weren't hiding the boost via MAP clamp or a Piggyback.(neither of which I would do with a $35k car.)
This is what your OP sounded like to me,
I went about 50 %throttle,boost came on, bang! something that resembled fuel cut, and the car is in limp mode.
Now add what all I have had to say into your equation and the solution becomes a little clearer.
tune the car.

 

if it was a TQ issue I would like to think you would be experiencing it more at full throttle than 50% throttle, or at the same frequency.
But in this instance it is just part throttle.
Yes as I have said before it is a matter of tuning.

 

bchappy, who said the AFR's were 14:1? Wasn't me. Of course I don't want 19 psi and 14:1 afr's, don't make things up to add to the conversation........the AFR's are deep in the 10's at that boost level and part throttle.

I agree Al, it would make sense it is a torque problem which is some calculation and since the boost is high at part throttle I am in agreement. I wish Ecutek would hurry the F up.

PDXEVO, I don't remember the code but that may have been it, did you get one too?

 

Thanks for putting it out there for people to see, id be going insane esp if it happens to me and nobody else said anything!

 

Dave a similar thing happens to guys on VW's. W/O chip (eprom) tuning the 1.8t guys get the same problem.

I did something a few years back to my buddies Audi TT and many followed afterwards After looking over wire diagrams and studying the fault he was throwing I found if we tricked the ECM with a diode the problem would go away.

For those that dont know what a diode is... an electronic device that has two electrodes or terminals and is used especially as a rectifier. It will only transfer info 1 way.

Our faults where not TPS faults, but the ecm would cut throttle back ALOT. The fault was an over boost fault. After placing the diode into the wiring the car would at times throw a long term fuel trim lean. But the car never had any problems with this mod done to it.

If you cant wait for tOOning software I guess you could always cut just 2 wires

It would look something like this

 

Sucks more when it happens at the track Limp mode is great for a 19 @ 54mph

 

Very curious... What piggyback system are you tuning with???

 

Would be easy to prove your airflow /TQ equation. put it back on the Stock boost controlers and try it again. at least we will know to turn down the boost until it can be corrected. I understand your theory but turning down the peak boost should inturn lower the part throttle levels to a happy range.

 

I dont know what code my car is throwing out but today will be the second day i have returned the car to the dealership. friday night after they told me i probably bought bad gas... which i didnt...

i had the CEL come back on only this time the asc completely shut off.... wouldnt come back on unless i let the car sit and the key out for at least 5 minutes. at least they are giving me a loaner...


car is completely stock with just over 2k miles on it now

 

The condition that Dave is talking about seems like a very obvious protection mechanism for a car with a drive-by-wire throttle. Look at it this way, what would happen in the unfortunate case where the electronic throttle body stuck open? You would give the car a small amount of throttle input, but it would be sucking in way more air than it should (and making more power, possibly when you don't want it to!) since the TB is stuck wide open.

So clearly there is a check in the ECU whereby it compares the throttle position to the airflow as measured by the MAF sensor and goes 'limp' if the values are out of a pre-determined range. Since the check is a protection mechanism against the throttle sticking wide open (a VERY BAD THING!), this check wouldn't make sense if the 'torque-requester' (err gas pedal) was at 100% (to the floor) since you want the TB wide open at that point. Hence I wouldn't expect to see this particular limp mode condition at WOT.

One note of caution ... obviously tuning software is going to be able to eliminate this problem, but tuners should probably be careful not to completely eliminate the check or make the comparison airflow values toooo high. If so, the customer could find themselves in a really ugly position if the throttle really does stick wide open someday and now this particular protection mechanism is completely gone