To start off with the standard greddy turbo ran great with the MS and this tune so its just got to be a tuning issue with the new T-19 upgrade on the compressor of the turbo.

Its runs and drives fine but when it gets under boost 13+ psi it hickups. I data logged it and it will be posted below. If you look at it at 5800rpm is when the problem is. The data log shows a spike in rpm to 11000rpm than back to 5700rpm? If you watch the mapdot screen it seem to be when it is going from the 184 to the 212 kpa range and as many time as I have tried to smooth out the transition its still bad. What an I missing?

 

I was thinking of adjusting the 184-212 to be closer together so the change is not so drastic?

 

Overboost protection kicking in possibly. What's it set for?

 

16psi

 

Try putting it to 18 and see if it does it.

And looking at your VE table, the transistion from 184 to 212 is crazy. Like a 20 point DROP? Weirdness. This is my VE table for reference. Smoothness goes a long way.

 

Ok I'll try it.
AS far as the VE goes, I have been driving up and down this farm road for two hours and I have mapdotted (that a word?) a very easy transistioning table and it still did it. I just wanted to know if I was on the right path.

So whats with the 11K spike? Mean anything?

 

I don't know about the RPM spike. I saw it had a correlating fuel spike to zero, which is what made me think overboost could be kicking in. Or maybe vtak kicked in for just a sec.

 

post the msq and log file.

 

k

 

change your wheel decoder settings to this:




also increase the threshold of you MAPdot try like 150kPa, it's pretty active before the reset and blip while in boost.

 

Ok the wheel settings changed.

Whats this mean?

also increase the threshold of you MAPdot try like 150kPa, it's pretty active before the reset and blip while in boost.

You lost me.

Found it, in accel decel mode screen.

 

are you running low impedance injectors in PWM mode?

i ran into this exact issue... it was caused by flyback voltage from the injector coils messing with the distributor signal.

thats all i got...

 

Ok this was the last test ride of the night, least thats what the nice cop told me

Made all changes recommended:
mapdot
wheel decoder
smooothed out my VE table
Over boost set to 17


Its like a bucking bronco! This can give a guy whiplash! When it cuts it cuts! On the 2nd data log it locked up Megatune Don't know if that was a MS problem or just the laptop bouncing around the car as it bucked. Also the tach on the dash wildly drops fast when it bucks. Almost feels like an electrical problem But I have touched nothing electrical.

Here the new info...

 

Spiffy new smoooth VE table to see if that was the issue. Any it pretty

 

Here the screen shot of the datalog when it locked up.

 

Does your TPS work? Will look at logs later tonight.

 

Got me?



Don't know if this means anything but it will not miss in 1st gear, 2nd 3rd yes but not 1st?

 

You have noise. The map signal isn't stable, neither is the AFR. How is everything grounded? And your Throttle Position Sensor isn't reading right. It shows 0 all the time.

 

Well if you feel like switching back to the old greddy wheel, Ill buy that one (but really it sounds like overboost somehow?)

 

the issue is when the dizzy signal spikes to "15k" the ecu revlimits and cuts fuel. shut off your revlimiter entirely and the bucking will probably turn into a less violent hiccup.

obviously thats not the best way to fix this though, lol

you didnt answer my question about the injectors...?

my problem only occured at specific PW's and rpm's, its possible that with the smaller wheel you never hit a PW that causes the issue. its also possible that in 1st you dont stay at that PW for enough cycles to cause a problem. i could rev out to 7k in any gear as long as i was at part throttle/partial boost. at full boost i would hit a specific PW/current load from the injectors and it would freak out. this was like 2 yrs ago so i dont have any logs to show you, sorry.

Btw I was running 470cc 323 GTR lo-z injectors when this problem occurred. i swapped out for some 360cc GTX hi-z injectors that I had and the problem was immediately gone. Later I stepped up to 550cc RX7 hi-z injectors, still no problems.