Toyota MR2 3SGTE MSPNP Tuning Help

[Fuzzyd]

Hi guys,

Car Details:
1986 Toyota MR2 MK1.5
GenII 3SGTE from a 1992.5 JDM Turbo MR2
Megasquirt PNP with TS9395 base map for PWM Boost Control
DIYAutotune Boost Controller
DIYAutotunes Intake Air Temp sensor
CT20B Turbo
3" Catless downpipe and Exhaust
Stock 440cc injectors running without a resistor pack
EDIT: Walbro 255lph pump.
Air to Water Intercooler with 2.5" intake piping
Innovative LC-1 Wideband
Engine wiring is completely custom built by me.
GM knock sensor
70amp alternator


I did my best to dial in the boost duty map tonight. I have it set up to run <15PSI at the moment, until I can get everything dialed in.

A few concerns I have:
1. I couldnt get my Injector Dead Time dialed in. I tried doing the switch between 2 and 4 squirts but during 4 squirts it ran incredibly lean... like 19-20, where as with 2 squirts it seems to run perfectly at 13.8-14.5.

2. I havent yet started tuning Acceleration Enrichment. Im still trying to perfect the VE table. Can anyone see anything odd about it?

3. Sometimes under hard boost Ill do a shift between 1-2 or 2-3 and the car will immediately loose power after I let the clutch out, as if its hitting fuel cut. What could this be from. Ive only been able to replicate it twice and Im scared to do it more.

4. What is my next step??


ATTACHED: Is an MSQ of my current tune. As well as a Datalog of some highway pulls with boost in 3rd 4th and also 1-2-3 at the end IIRC.

First off, shiiiiIIIiiiitt, the base map of megasquirt seems to give WAY more umff to this car. So happy with this upgrade.

Any help is appreciated!

Cheers!

[Matt Cramer]

Hi guys,
A few concerns I have:
1. I couldnt get my Injector Dead Time dialed in. I tried doing the switch between 2 and 4 squirts but during 4 squirts it ran incredibly lean... like 19-20, where as with 2 squirts it seems to run perfectly at 13.8-14.5.

Don't worry too much about getting it spot-on; as long as you don't have it too long and have it keep you from getting a proper idle, you should be OK.

3. Sometimes under hard boost Ill do a shift between 1-2 or 2-3 and the car will immediately loose power after I let the clutch out, as if its hitting fuel cut. What could this be from. Ive only been able to replicate it twice and Im scared to do it more.

Not seeing it in this log, but you could be bouncing off the rev limiter or the overboost protection.

4. What is my next step??

Like you said, the VE table isn't fully tuned...

[lagos]

Nice to see another 2nd gen 3sgte around here!

1. I couldnt get my Injector Dead Time dialed in. I tried doing the switch between 2 and 4 squirts but during 4 squirts it ran incredibly lean... like 19-20, where as with 2 squirts it seems to run perfectly at 13.8-14.5.

I had the same problem until I realized how to do this procedure correctly. You need to switch from sequential to untimed injection, then when you are switching between 2 and 4 squirts, you have to fully power cycle the ecu. If you don't do a power cycle, the afr will read extremely lean like you are seeing.

I ended up with a dead time of 0.773, and 0.080 for the battery voltage correction for the stock 440 injectors. Curious to hear what you end up with.

2. I havent yet started tuning Acceleration Enrichment. Im still trying to perfect the VE table. Can anyone see anything odd about it?

Do a data log and look at your afr, tps, and tpsDot. TpsDot is the amount of change that the accel enrichment is based on, so by looking at this you will see where you need to add fuel. Start your first value and your threshold at something like 15%. The 75% default is too high to be useful.

3. Sometimes under hard boost Ill do a shift between 1-2 or 2-3 and the car will immediately loose power after I let the clutch out, as if its hitting fuel cut. What could this be from. Ive only been able to replicate it twice and Im scared to do it more.

Make sure your db9 connector is screwed in all the way and not just plugged in. If it comes loose, it could cause a stumble as tuner studio looses contact. I think this was greatly resolved in the newer firware versions, you make sure you are running the latest one. If it still keeps happening after that, try to datalog it.

[lagos]

Don't worry too much about getting it spot-on; as long as you don't have it too long and have it keep you from getting a proper idle, you should be OK.

Sorry Matt, but I'm going to have to disagree. I think getting the dead times right is the key to having consistent afr is all kinds of conditions. Before getting mine dialed in, the car idled just fine, but warm up enrichment and mat corrections were basically all over the place and this lead to a lot of frustration in the past year. I wish that the correct procedure of tuning the dead times was included in the mspnp documentation and that its importance was stated in bold on the first page, like it is with a lot of other ems systems.

[Fuzzyd]

Thanks Lagos. I'll work with your dead time calculator this afternoon and start returning my VE.
How did you calculate battery voltage correction? Haven't read about that anywhere.

[lagos]

Thanks Lagos. I'll work with your dead time calculator this afternoon and start returning my VE.
How did you calculate battery voltage correction? Haven't read about that anywhere.

Set the battery voltage correction to zero and find your dead time. Once you have found it, disconnect the signal plug from the alternator to allow the voltage to drop and adjust the battery voltage correction until your afr is the same as it was at 14v.

[Fuzzyd]

Thanks Lagos. I'll work with your dead time calculator this afternoon and start returning my VE.
How did you calculate battery voltage correction? Haven't read about that anywhere.

Set the battery voltage correction to zero and find your dead time. Once you have found it, disconnect the signal plug from the alternator to allow the voltage to drop and adjust the battery voltage correction until your afr is the same as it was at 14v.

boy, that will be tough to do without burning myself on my muffler. I supposed i could just hook up a switch to the signal wire where I have it running in my trunk... or just cut it and re-solder it.

hmm.

I wound up with .815 being the best dead time.

Have a couple other issue Ive been trying to figure out.

1. I cant rev past 6900rpm. I have included a log of this attached revmax6800.msl

2. I have a weird issue where if I stab the throttle from idle, or while trying to rev match in deceleration, that my throttle response lags. I see that my pulse width goes up to 16 with or without Acceleration Enrichment,sending my AFR down to 9.5ish. With AE on it just stays at 16 for a little longer. File is revlagapril13.msl

[Matt Cramer]

I'm seeing a 125% duty cycle at that RPM - you're running out of injector or fuel pressure.

Do you have a lot of the pulse width spiking to 16 ms?

[Fuzzyd]

Matt: are you refering to +6800 when you say I am running out of fuel? If so, then that makes sense. So then, Ive maxxed out my fuel system?


As for spiking to 16ms. Yes it is happening a lot. But only seems to do it when I try to blip the throttle from low revs. I havent noticed it happening when I hammer the throttle from a higher rev point, but Ill watch for it.

But I may have had a brain wave. Maybe Ive been doing something wrong. To disable Acceleration Enrichment I have been setting my RPM points to 8000 and 8000 because my rev limit is at 7200. And then I am also putting threshold% to 1000. But maybe I am still getting AE but its immediately going 1000 and adding +10 PW... which would make it jump from 6 to 16. Does that make sense.

So, Maybe I should just lower the highest PW point to +8 (or lower) instead of +10 and see what happens. Ill try that tonight if its not snowing.

ALSO: I have a Walbro 255lph pump. I forgot to mentioned that in the OP. Ill edit it.

[Matt Cramer]

Yes, it's running out of injector at 6800 RPM.

The pulse width spikes may be something other than AE. I'll need to see them caught in a log.

[Fuzzyd]

Im working on sourcing a larger fuel rail and 800cc injectors which should (hopefully) solve all fueling problems Ill ever have. Wont need to upgrade to larger injectors unless I go beyond 500whp or find E85, both of which are unlikely.

As for the 16ms spikes. I changed the PW curve to
75:2
250:3
600:4
1000:5
and it seemed to fix the problem. BUT it snowed 4 inches here , so I cant get a log to prove its working or even doing anything.

[Fuzzyd]

Okay, so I am back at it again, finally.

I have installed 800cc injectors and am now having problems getting things to run like they used to. Actually I thought I had it running fairly good yesterday, then today it just seems to be crapping out.

My points of worry
-my VE chart shows incredibly low numbers. Is it normal to have VE at 7-10 while idling? Seems extreme since the basemap numbers were in the 40's.
-getting a stumble on acceleration, I think its from poorly configured AE, but still working on it.


I am certain there is something screamingly obvious that I am forgetting. So if someone would please review my MSQ and log and give some pointers, I will be very pleased.

FD

EDIT: Also note that I have installed a new clutch, so only mild driving for now. Also only boosting to 10-11 psi till I get things put together properly.

[pit_celica]

Wow, these injectors must be really big. You are running 1.8ms at 3000 RPM and 60kPa and you still get 13.6 AFR.

Are you sure these are 800cc/min injectors? Maybe they flow more than they should. Did you connect your FPR to a vacuum/boost source?

I don't see anything obvious in the log or in the msq.

Sam

[Matt Cramer]

Okay, so I am back at it again, finally.

I have installed 800cc injectors and am now having problems getting things to run like they used to. Actually I thought I had it running fairly good yesterday, then today it just seems to be crapping out.

My points of worry
-my VE chart shows incredibly low numbers. Is it normal to have VE at 7-10 while idling? Seems extreme since the basemap numbers were in the 40's.

Usually this is a sign the injector opening time is set too high for the injectors you are running. Try getting this dialed in first, and then work on the AE.

[Fuzzyd]

Right on. Appreciate the input.
Yes they are 800cc. I double checked the codes on the sides of them to be sure. All were 800cc SARD.

I thought I had the injector dead time set by following the guide above, but Ill start over. I guess first thing would be to readjust the VE table to 25ish and also adjust dead time to around 0.8-1.0.

Another thing I did last night that may help with timing... rather than changing the Tooth Angle electronically I instead adjusted the distributor mechanically by physically rotating it. I was able to rotate the distributor and align it nearly exactly 10* (with fixed timing) without adjusting the Tooth Angle under Trigger Wheel settings. Maybe this is something that should be Captain Obvious, but it was never explained or mentioned at all during the install instructions. Maybe it wont make a difference at all. See once.

I am going to try and take the afternoon off work and get this thing running properly.

[Fuzzyd]

Part number 1001-87093
Celica GT4
SARD 800cc.

According to This website the Lag Time is 0.75ms. Am I assuming correctly that Lag Time = Dead Time?


EDIT: Confirmed from SARD website. I have Dark Blue 800cc injectors which should be at 0.75ms. So yes, my dead time was WAY off. 150% of what it should have been.

[Fuzzyd]

Oh Wow what an improvement!

I changed the lower VE numbers to 25 and put Dead Time to .750
Started right up.
Idles smoother, although a bit higher.
VEAL made a few changes but actually put the numbers UP to 32-38.

Drives a lot smoother in lower RPM. Hopefully this allows AE control to work a lot easier as well.

Thank you so much for the help. Ill post a new log soon so that someone can look it over for anything else obvious.