Help with tuning the upgraded Greddy T-19 Turbo
 

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.

Attachment 208661

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:

http://diyautotune.com/images/cartec...eel_decode.gif


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 :jerkit:

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 :mad: 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:crx::bang: 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 :giggle: (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.

Sorry did not answer just did not understand how injectors could be the problem, now I see.

The injectors I have are out of a RX-7 460cc

I'm going for a drive to test the rev-limit theory.
Thanks

Ok so that did not help. Raised the rev-limit to 25,000 and tried it again and same issue.

Logs...

Are you using COPs?

Just thinking and typing, the TP is not reading, so I pulled a data log from November track rental that had a pass logged.

I also thought the TPS on these cars was on and off only? Why did it only move once on this log from 7 volt to 8 volt?

Remember this log is from when it ran great!

I'm confused.

No.

Are the injectors low or high ohm? How is everything grounded? Echo, echo, echo...

Post a picture of your timing table.

or email matt cramer your logs and msq.

Patsmx5,
Injectors are high ohm injectors from a RX-7 460cc red top.

Grounds are to the back of the fuel rail area where that ground post is. That was what was recommend when I installed Brain's MS.

Samlo1,

Here ya go:

Don't know of it matters but the car still has 100 octane in it from track rental in November.

Sent him a PM here. :)

You've got noise issues, which won't be solved by adjusting the settings. These manifest themselves differently in different logs; sometimes it's a reset, sometimes it's a RPM spike. You will need to get rid of the noise.

I'd start by inspecting the grounds. How is your Megasquirt wired up?

It a parallel installed MS built by Braineack, installed as per his instructions. Has work excellent for almost a year! Than I install a rebuilt turbo and touch nothing else and this? Strange.

Grounds and noise, didn't I say that earlier? :) Hence why I asked about your grounding. You need to elaborate on it. Note exactly how every ground is ran. Then remove and clean every one, including the big ones, the ones on the PPF, the physical connections at the battery, etc.

Got it. I though you were just talking about the MS ground, I cleaned that.

Thanks

Well problem has been solved. And boy do I feel stupid!

Here goes, my car has been down since Nov as some of you knew and I have been working on the Lemons motor for the other car. So in doing the coolant reroute design I wanted to see how much room there was behind the head when the motor was in the car. So I unbolted the coil pack to see the room there, well I bet your guessing the rest.....REMEMBER TO TIGHTEN THE COIL PACK BOLTS!

Brain, should I put back the wheel setting I changed?

Back to tuning......THANKS ALL!

So the coil pack wasn't bolted down? How's that cause a problem? I can assure you my coil pack isn't bolted down... And it works.

Got me...the bolts were there gust hand tight. Bolted them down and it works fine.

Well, you need to figure out what it was. Though it should be bolted down, it should not affect the performance of the coils. Perhaps you have a wire or connection back there that was being pushed on by the loose coil? I dunno, but I'd find out what's going on.

must have been a loose connection. leave the settings.