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L28ET base settings and tables?


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Hey everyone. I'll be the first to say in this topic that I have no idea what I'm doing anymore. Car's popping out the intake, running super rich, falls on its face, appears to have just killed an injector (which I'll be replacing this weekend)... 


Details (what I know):




0.020" bore, fully balanced rotating assembly, 5-angle valve machining, self-oiled 'A' grind cam, minor port cleanup, fortified with ARP hardware. 


Nissan 45v1 turbo (R33 Gts-t, similar in flow characteristics to stock turbo)


Equal length header


Ford Coyote 32lb/hr (336cc/min) injectors (was running 50PSI, now at 40PSI), high impedance, binned the resistor. 


2.5" exhaust from the turbo back. 


MS2 V3.0 (can't remember firmware ver. Last installed circa 2011?)


Ford EDIS ignition (escort CPS, B4000 controller, '06 Mustang coil pack). 


I know I'm most likely doing a number of things wrong, but I'm not sure what anymore. I change one thing, it gets worse, so I rewind. I change another, it gets better, so I go down that path, and then it gets much worse, then I get lost. I just wanna get this thing to something resembling driveable, so I can take it to someone who actually knows what they're doing. 




You'll have to excuse any blurriness in the pics. Here's an msq... 2021-04-29_19.20.12.msq


I've been building this car patiently for the past 8 years, and I'd like to start driving this summer if I can. 

Any help/insight would be greatly appreciated.


*EDIT* I also live in Calgary, Canada, which I believe is roughly 3700 ft above sea-level, and my wideband is currently not operational due to the dash being out of the car. 

Edited by Barrel_Ball
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I run SDS so I don’t know how to tune mega squirt. I can give you some broad tips. 

first, get it idling.

Try to tune for ignition timing before worrying about AF. Are you using a timing light to ensure the what the computer “thinks” is your timing matches what you are seeing at the crank pulley? If not, adjust to factory specs with the light, and set that as your new baseline on your tuner. Ignition advance is needed on throttle input (TPS or MAP), and higher rpm’s. If you eliminate the advance all together, it will just run inefficiently and with poor response. Point being, go safe on ignition first so you can confirm that’s not your problem. If you advance beyond a certain range, the engine will die so keep your advances incremental 


On the AF, you will be adding a little more fuel per RPM from idle up to about 3000rpm. What I mean is, 2000 rpm will need a little more than double the fuel of 1000rpm. Above 3000, your rpm/fuel relationship should be more linear. This is because the engine’s volumetric efficiency peaks and stays pretty steady after 2500-3000 rpm on a stock cam. 

the relationship between how much fuel you need per vacuum or boost is dependent on your MAP sensor. This should be pretty linear, or the base mapping from your EFI should be OK.

so back to my original point, get it to run OK at idle, then work from there. This is how I tuned my L28et before I put it on the dyno. 

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  • 2 weeks later...

You need to chill out on your timing . It’s hard to see the pic , but you have a ton of timing at 100kpa. I run NA - so can’t help you above 100. You are bringing on way too much timing too early . I wouldn’t be above  33 degrees at 100kpa anywhere on the scale for now . I don’t bring in full timing(36) until around 3000-3500 rpm . ESPECIALLY with a turbo build I would get more conservative .

As said above - verify timing with a light . Verify timing marks on pulley . 
Your VE tables look wonky too. You are pulling fuel way early - before you make full torque . 
Id suggest finding a tune from someone’s else car 

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Can you afford a wideband gauge? I could give you some tips on using that to tune your AF. You can tune the RPM fuel increments while idling at various RPM’s, and will need to be on a deserted road or mostly empty freeway to tune the manifold pressure fuel increments since you need the load. Stick to 4th gear which is 1:1 on most transmissions.

Glad you got it to idle better. Definitely check your timing with a light. Suggest using factory settings to start. I can take a picture of my 280zx Haynes manual if you need the numbers. Always room to tweek the timing after you get your AF right. There is a small relationship between AF and timing (where richer mixture will allow for a bit more timing advance) but you are not there yet. For now just assume they are 100% independent variables that don’t effect each other. 

Edited by AydinZ71
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