f575gtc

First off
I am working with a 92 NA 1.6L, stock injectors, 93 Octane, AEM Wideband UEGO 41xx series, no AFM running a GM IAT.

I installed a basic turbo kit and inter cooler over the winter and a MegaSquirt PnP first gen PnP.

I flashed the ECU to 9093 no AFM and uploaded the base 9093 no AFM map.

I can get the car to start and run, but it runs terribly, and my AFR starts at a nice ~14.5 AFR but then within 10 seconds my AFR starts creeping up and goes to ~18:1, plus the idle starts bouncing, the engine almost stalsl then goes back up to a 1300rpm idle (cold).

On these .msl files the .52 is my start up and idle, the .51 is the car idling, and me tweaking the required fuel, if I increased the required fuel ms, the idle stabilizes but the AFR is still high...

Also I have selected the LC-1 0-5v option in the Wideband settings because its the closest to my AEM, my tunerstudio doesn't have anywhere to calibrate the AEM if I use custom linear, what gives?

I thought it was a vacuum leak at first, but my MAP looks pretty stable, and ~35-40 KPa is normal at idle no?

Any help would be great guys!

hornetball

iTrader: (4)

Wow. Where to start. First of all, where are you?

The better route would have been to install the MSPNP, learn how to tune it, and THEN install the turbo. If you had done some reading here you would have come across that recommendation.

Be advised that stock 1.6 injectors and stock fuel pressure will not feed enough fuel to the engine for turbo operation. You need larger injectors. There are plenty of injector size calculators on the net for guidance.

As for tuning, first order of business is to tune your idle. See here (post #11 and subsequent): https://www.miataturbo.net/megasquir...me-help-57133/

Once your idling OK, you tune the rest of your VE table using TunerStudio's autotune function or MegaLog Viewer's VE Analyzer function.

Obviously, you need accurate WBO2 readings for this. Here's some discussion on that: https://www.miataturbo.net/megasquir...-lc-1-a-58873/

f575gtc

I am in CT, I know I should have waited on the turbo.

Question, the EGO switch point is defaulted to 0.510v, after doing some research I found the EGO switch point for the wide band should be ~2.375v.

Is the default number in the EGO switch point normal to be 0.510?

The EGO switch point is what tells the ECU what voltage represents 14.7,
the AFR should be reading about 10:1 at 0v right? so 0.510v seems way off to show 14.7, but my log does show the 02 is at 3.8v which sounds about right for a ~18AFR.

Finally I only plan on running 6psi out of this turbo for now, I read the stock injectors will run a turbo at low boost no problem..

hornetball

iTrader: (4)

The default value in the MSPNP basemap assumes you have not installed a WBO2. 0.5V represents stoichiometry on a NBO2.

f575gtc

Ok so I should set it to about 2.375v? which I did

UPDATE:

I got a NICE steady idle!!! I was able to get my AFR to read stoichiometric or just about at ~14.5 at idle, as my motor warms up, and the ASE (which I set to 60 seconds) decays, my VE wants to richen the idle as it drops to 1200 and below I was sitting at about 13.8-14.1 as the idle dropped, which is strange because the target AFR i set around that area is 14.8.

Now here is one thing I am concerned about, the only way I was able to get the AFR anywhere near 14.7 and not pegged at 18afr was to increase the required fuel way over the recommended values from the calculator, the software recommended 13.3ms I had to set it through the roof at 17.8

Now I know every car is different, but I am concerned I am doing something wrong here, the more I raise the number the fuel gets pumped in right?




Also my KPa is right around 27-30 now around idle, down from the 40 it was at.

sixshooter

iTrader: (12)

Is the MAP sensor setting correct for the particular MAP sensor that is in your MS? There were different options available in them.

The stock injectors are capable of working at a few pounds of boost, but only if you buy additional devices (RRFPR). You stopped reading too soon. For the same price or less, you can buy used set of rx7 460cc injectors. If you don't set your overboost protection at 108kpa and work your way up to the maximum of 85% duty cycle, you will likely go lean and blow your motor. Start with your wastegate flapper arm disconnected and see what you get.

f575gtc

I actually went back and I am hearing a slight hiss from around the injectors, I might be experiencing a leak from once if the seals.

I believe I have the right MAP sensor selected, it comes with a 2.5bar sensor, so I selected the 250KPa sensor.

Also are the RX7 460cc injectors plug and play? I see there are high impedance and low, which would I want for the 1.6 fuel system?

hornetball

iTrader: (4)

High impedance.

AFR table is usually not used in the idle region (you have control of that in the "Exhaust Gas Settings" dialogue). In general, the AFR table is a secondary control. Your fueling is primarily determined by ("Req Fuel" x VE). In the regions where you've enabled EGO gain (Gego), some correction to the AFR table will happen, but it will be limited to the authority you give it.

Where does correction to AFR not happen (and why?):
1. Idle area below the "Active Above RPM" (stability);
2. When warming - below the "Active Above Coolant Temp" (stability);
3. When above the thresholds for open loop in the "Open Loop Mode" dialogue (to prevent blowing up your engine if the WBO2 reading is incorrect)
4. Maximum Gego correction is limited to "Controller Authority" (to prevent blowing up your engine if the WBO2 reading is incorrect).

Suggest you:
1. Fix all vacuum leaks;
2. Upgrade injectors and, until you do so, take steps to limit boost per Sir Sixshooter;
3. Set "Req Fuel" per the book and leave it alone;
4. Adjust fueling by adjusting the VE table -- you can do this by hand in the idle region -- use Autotune or VE Analyzer to tune the other regions;
5. Look at those links I posted earlier.

f575gtc

You guys don't know how much I appreciate the help!

I dove into the deep end without knowing how to swim and now I need to learn how to swim to make my way out of the pool :(.

I just ordered 4 RX7 460CC high IMP red tops for $75 decent price?

Also how often do old injector seals leak? should I reorder new seals for the injectors so I know there will be no leaks between the intake and injector?

f575gtc

I some how managed to screw up the injectors and I received 460cc high imp 87-88 NA RX7 injectors with square connectors.

Should I sell them and get the right ones or can I just buy the pig tail connectors and wire them in?

f575gtc

WOOT!

I had to go to 3 different stores but I got all the connectors for the injectors.

So I have the 460cc injectors in.

I FOUND the leak, there was a tiny nipple under the throttle body I didn't see.

I can't hear or see any other leaks or missing houses.

My only problem now is I still have a crazy high AFR during idle, about 18-20:1, once the car warms up and the idle drops the MAP drops to about 25 and my AFR starts to crawl down a bit to like 15-16:1

I went into the engine constants and adjusted the Req. fuel using the calculator with brought it down to about 5.6, do I need to adjust the pulses or anything else with these RX7 injectors? They are high imp, i double checked its Ohms and they are 12.9.

sixshooter

iTrader: (12)

I'm using RX7 460's and my req fuel is 7.4.

f575gtc

hmm then the calculator isn't accurate? or I should use custom numbers that I hit my target AFR with?

skinny

don't tune your afr's with the req_fuel!

Braineack

iTrader: (62)

it doesn't matter

f575gtc

Update!


I fixed ALL leaks, no more air leaks, or fluids leaking connected my boost gauge so I could find out what vacuum I was pulling or boost if I was making any...

MAP is not idling around 25-27KPA, I have a stable idle. Boost gauge shows I am pulling about 18PSI vacuum (I think that is what the gauge measures vacuum in).

I went into the Fuel VA table and noticed everything was set in the teens around idle KPA, so I used the table generator, and punched in some numbers for the HP and TQ (guessed according to the instructions) and it gave my VE numbers around 38-40 at idle KPA and they scale from there.

Now my AFR idle is at 14.3.14.7, still is a bit bouncy.

Also Tunerstudio is reading about .2-.5 higher AFR than the AEM gauge.

Now my problem is when I slowly apply the throttle the engine revs up easily, but if I quickly rev, the AFR hits about 10.1:1 and the engine bogs/cuts hard at about 2500rpm then builds up, so I think I an squeezing waaay too much fuel in.

I will post my log when I get home from work.

Just wanted to update with the progress.

sixshooter

iTrader: (12)

Sounds like maybe too much accel enrichment if numbers are going down to 10 or below. Did you change to a variable throttle position sensor or are you using the stock one? If stock, make sure your settings are not giving you accel enrichment based on TPS.

Braineack

iTrader: (62)

you used the fuel map generator and wondering why your fuel map sucks ****?

f575gtc

I am using the stock TPS, which seems like its not even a true TPS unless I had the auto tps or one out of a later year.

How else was I supposed to get a base fuel map? pull the numbers out of thin air?

Braineack

iTrader: (62)

Maybe a basemap?