Update your Stage 1.x chip to include the Stumble Elimination feature:




Regards,
Mike Montalvo

 

I've daily driven this for a week and drove to and from Sevenstock and it ROCKS!

 

Week #3 here, all problems have been eliminated.

 

Could you please explain what was changed?

 

The code that decides when to turn on the secondaries was changed from PSI based to load based.

 

Sounds good, I just placed my order and can't wait to try it out.

 

how hard is to change out chips. my car has the stumble everytime i drive it but i cant send the ecu cause i need to drive my car to work

 

I'll try and do a video tomorrow.
Its pretty easy. Takes about 5-10 minutes.

 

Heres the video. Enjoy! hahah

http://www.jumpcut.com/view?id=F640E...02000423CEF5F6

 

looks easy enough

 

So far so good, stumble is gone, response seems better and idle slightly increased.
On a side note what are the instructions on returning the core any rma number required?

 

Just send it back, the serial number on the chip will be enough to figure out who's it is.

 

Ok thanks...
Great job btw.

 

I could have used this 6 months ago.

 

the car is 98% better to drive but it seems like my stumble moved to 10 inches of vac on my car
. its by no means as bad but its barely barely there.. thanks for the upgrade guys how does the car know the load????

 

Oh damn, and I was wondering where my stumble is coming from.
At the end I amplified the boost sensors signal a little ( about 0.2 - 0.3 V )
and its better now.
Also enriched the mixture a bit at 3400 rpm with my afc.

Im a bit disapointed now, that the rtek chip is the problem
but Im also glad now to know that it isnt the wiring.
I already checked all the ground points, and thought about buying a power cap
but now I know I dont have to

-Patrick

 

The Rtek chip is NOT the problem, its the solution to a well known problem that happens even with the stock ECU.

 

Oh, okay,

misunderstanding

sorry then

thankfully I solved the problem my self

-Patrick

 

I been driving on the update chip for a couple weeks now, and its greatness. I've had that stupid stumble since day one. After doing all the recommended grounds, injector cleaning, and adjustments, it improved but never fully went away.

Now all I can say is, greatness. If you have an S4 TII buy this chip.

Well done DTI/Rtek.

 

so they basically changed the staging point to load based instead of rpm/boost? What would be really nice is if they added an adjustable staging latency correction %, like some of the other EMS offer

 

What exactly would a "staging latency correction %" correct for?

 

well i suppose it wouldnt be an actual correction %, but heres my take on it:

I believe other ems have option of the running primary injector p/w a few seconds longer after staging. so for example say you are cruising along, seccondaries off, primares at 4ms p/w. then you go wot, and staging turns on. normally, the injector p/w would simply divide into 2, so primaries get 2ms, secondaries get 2ms.

For a brief moment immediately after staging, the ECU is sending 2 ms to both sets of injectors, but due to injector inductance, wire resistance, etc, it takes a few cycles for the secondary injectors to actually start firing for the full 2ms, causing the engine to stumble, since its getting half the fuel it should. I think this is the cause of the staging hesitations everyone is seeing, especially with aftermarket low-imp injectors. By changing the staging to load-based, it improves the hesitation by delaying the staging to later in the map where longer p/w will not be affected as much by the secondary injector turn-on latency


It would be nice if you could add a "# of cycles" adjustment, so have the primaries still fire at 4ms p/w for a set # of cycles after staging (while secondaries are firing 2ms like normal) to make up for the secondary injector latency. This would give it a little extra fuel immediately after staging to eliminate any hesitations. The user could adjust the # of cycles, according to the severity of hesitation, since each setup will probably have different latency, etc


does that make sense and sound possible for rtek? I think it would cure all staging hesitations for good

 

Megasquirt does it in that exact fasion, I would imagine other standalones work the same. It works very well in both eliminating the stumble and lean/rich fuel mixtures right at transition.

 

quick question to everyone who has had the chip change. before the change, did anyone experience the stumble in the 3200ish range while the car was stationary? i.e. at a stop?

 

If the pressure sensor was not seeing vaccum at idle it would switch to the secondary injectors and could stumble that way.