NA is best - 3.1L M20 w/ ITB's

[darvo]

Update?

[Raxe]

Update?

Actually just received the Megasquirt today, excited to start reading and fiddling around with it. :)

After a lot of researching and looking around I ordered another set of injectors too, settled on a set of 24lb Bosch Gen 3's this time which I think should match my goals well. Unfortunately I have no idea when they'll arrive so I'll be waiting for that.



For now the car is back in my garage which is cold and dirty during winter. I may not make much progress until spring time... current plan is to prepare and do most of the remaining work on Easter long weekend.

[MVincken]

nice progress! definitely one of my favorite builds at the moment!

[QuiqueUy]

Great progress and build ! keep the updates up mate !

[Raxe]

At last a warm enough Saturday to work on the car again!

Finally received new injectors after my first order fell through, after a month of waiting Paypal stepped in and refunded me on behalf of the MIA seller. Found and grabbed another set which shipped promptly and look pretty nice.



Next step was figuring out how to mount the MSPNP2 case. It's longer and narrower than the OEM unit and uses different generic mounting mounts. Made a template from cardboard of the two overlaid and cut an adapter plate from aluminum.







On to the next issue: because of the aforementioned difference in length, the control unit sat too close to the firewall/insulation and the DC9 cable wouldn't fit. Ended up ordering a 90 degree connector that did the trick and just made the squeeze possible.



Tore apart the center console and ran a vacuum line from the glovebox area through the firewall to the FPR, passed through the now vacant grommet behind the pedals that was previously for the cruise control cable.



Mounted and installed the control unit:



Reinstalled my radio and tucked everything in:

[2mAn]

I can't wait to see what this will make when properly tuned! Keep it up

[uturn]

With the radio in the glovebox, curious to see what's in the cutout where it should reside. Gauges or stock radio?

[Raxe]

With the radio in the glovebox, curious to see what's in the cutout where it should reside. Gauges or stock radio?

Used to be a stock radio when it was all OEM, now it's... nothing. Just a factory blanking plate.

[digger]

is there a dyno graph of this thing prior to switching to ITB/MS? its always interesting to see the gains

[Raxe]

Actually made some progress today for the first time in quite a while. Finished the vacuum hoses for the brake booster and MAP, installed the IAT temporarily and did a "final" assembly of the runners and throttle linkage.



Fired it up for the first time... it runs and idles, but it's suuuper rich. I've set my fuel injector sizing using the calculator in MS for 24lbs but I haven't played with any fuel tables yet, is that my next step? I've only eyeballed the throttle plate sync at the moment as I don't even want to idle it for more than 30 seconds right now, standalone AFR is reading 11:1 but the headers are literally starting to glow after 30 seconds!

Took a quick snap of the live data at idle, I have no reference for what it's supposed to look like so any advice would be really appreciated.

1) Do the MAP and FPR need to share the same vacuum port? I have mine on different ports for simplicity sake but will change it if need be.

2) Is it normal to have such a high fuel load % at idle/1800rpm? Key on/engine off reads 90%.

3) Is it somehow basing its fueling on the lean Air:Fuel ratio shown (16.9)? If so, where might that reading be coming from? My AFR is standalone and not hooked up to the ECU at all.

Thanks in advance for any tips, I have a lot of learning to do here.

[digger]

im guessing you are using MAP strategy as opposed to alpha-n? this would explain why the load is so high since the engine is making stuff all vacuum. should be 100% at sea level ignition on engine not running

use the sync tool to get them in the ballpark of balanced even when cold so for warmup so there arent some cylinders over or under fuelling which can cause burn to happen in the exhaust or backfires if they are way out.

glowing exhaust means fuel is burning a fair bit in manifold due to slow/late burn (AFR way out or not enough ignition advance). AFR says lean on the gauge not 11:1

[ForcedFirebird]

I haven't had much luck with a vacuum manifold and SD. Use Alpha-N in MS with ITB's.

[Raxe]

im guessing you are using MAP strategy as opposed to alpha-n? this would explain why the load is so high since the engine is making stuff all vacuum. should be 100% at sea level ignition on engine not running

use the sync tool to get them in the ballpark of balanced even when cold so for warmup so there arent some cylinders over or under fuelling which can cause burn to happen in the exhaust or backfires if they are way out.

glowing exhaust means fuel is burning a fair bit in manifold due to slow/late burn (AFR way out or not enough ignition advance). AFR says lean on the gauge not 11:1

Thanks again for the advice, I am trying the "ITB mode" in MS which does use the MAP but I'll ditch it tomorrow in favor of Alpha-N, I'm thinking tuning speed density that way is a little out of my league at this point.

I'll look into the ignition advance as well, hadn't put much thought into that.

The digital MS AFR reading doesn't correspond with the Innovate I have separately installed with its own sensor, I haven't linked the two at all and am basing my mixture readings on the physical dash gauge vs the laptop - one reads 11:1 and the other 16.9:1 - maybe I have a setting wrong somewhere and the ECU is using my O2 sensor incorrectly. Will need to look into that further, especially if it's basing fuel on a false mixture reading.

I haven't had much luck with a vacuum manifold and SD. Use Alpha-N in MS with ITB's.

Appreciate the tip! I'm drawing that conclusion from searching as well, will play around with that tomorrow.

[ForcedFirebird]

In MS, you need to select the external WB brand you are using. In TunerStudio, go to "tools" then "calibrate AFR table". You will see a drop down menu to select one.

On another note, might want to connect the laptop directly to the innovative and make sure the output is set to 0-5v, as well as calibrating the sensor itself.

[Northern]

6.5ms on 24lb is like 2.5 times the amount of fuel I have to get ~14.7:1 at idle on an M52, so that can't be even remotely close.