Maxing out 510 injectors at stock boost

[Bouche Dag]

Car is a 92 AWD. Mods as follows: JDM EVO 1 RS engine with 16g turbo, 510cc injectors, 90 ECU (with pins swapped), BSE, o2 sensor is good, 3in. GM MAF w/translator, FMIC with dejon tool piping, -6an fuel feed line/custom fuel feed line fitting, summit racing high flow fuel filter with male -6an fittings on both sides (about the size of a co2 cartridge), -6an return line, wally 190, bored throttle body w/half shaft mod. That's about it for relevant mods.

I have a nasty issue in which I'm maxing out (93% duty cycle) my 510 injectors at factory boost pressure! The car has NO boost leaks. Any leaner and I get knock.

Do I need to get an AFPR and adjust the fuel pressure to compensate for the fuel lines and the IC pipes? Or do I need to get a different way to tune the car (DSMLink) as I'm just using the MAFT right now?

Car has no other driveability issues... 21 mpg city, 25 mpg hwy, pulls really nice and smooth, no CELs.

 

[jrohner]

well how rich are your AFR's?

 

[LandSpeed-DSM]

Bad voltage to pump? Clogged lines or filter? Kinked line?

 

[Bouche Dag]

I'm a bad DSMer as I'm going off of the O2 voltage. Which is right where it should be .92 at WOT

Pump is rewired and voltage is good. Lines are brand spanking new, no clogs/kinks.

 

[wranglerunner22]

I'm a bad DSMer as I'm going off of the O2 voltage. Which is right where it should be .92 at WOT

Pump is rewired and voltage is good. Lines are brand spanking new, no clogs/kinks.

Should probably be a good dsmer and get a wideband. <---Most responses will be this.

 

[Bouche Dag]

I figured. I need that and DSMLink real bad.

 

[LandSpeed-DSM]

Have you checked voltage at the terminals under load with a gauge? Because otherwise you really have no idea, rewire or not.

Consider running some fatter grounds in the engine bay, and a 150A fused link from the (+) alternator post to the (+) battery post.

.92v on the Front O2 is not especially handy when you look at how temperature dependant the output is.

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[Bouche Dag]

Here's a kicker for you guys: I had these exact same issues with another motor in a different shell with the dead nuts same setup (except the fuel system was stockish minus a wally 190. Injectors would max out, I'd get crazy knock, etc.

I took the ECU out of that shell and put it into the current one I have now. So I'm wondering if my ECU is garbage... It has been recapped by ECM tuning but it is a 90 ECU and it's not right for the car. I'm wondering if my IDCs would be any different with a proper 91+ ECU.

 

[Arthris]

Theres no differance in ecus other than the pins and the BIN thats loaded. 91+ uses the E931 Bin while the 90's used like a E742. Just looked at my stock EEPROM. Im at almost 90% on 750CC FIC's on stock 14B. You need to see what ## IAT is. If its hot after IC its gonna cause ## IDC's to go up. For me that was on pump 93 im running E85 in the tank and even with the extra fuel im still about the same as 93 IDC's

 

[okm12346]

Im having very similar problem. Once it pins the gauge to 10 psi and if I am to press on the pedal more it knocks and then there goes the smoke from the tail pipe. I started having these issues since I removed the boost controller and now the wastegate is directly sourced from the j-pipe. Before that it was pulling like crazy for 10 psi. I havent had the time to install the boost controller (manual) again. When it gets there I can see the Wideband going lean and I get scared and let off the pedal.

My setup is very similar to yours - 510cc, MAFT+SAFC, Evo9 pump rewired, b16g with Evo3 manifold and o2 housing.

 

[Bouche Dag]

@okm lmk what you find if you investigate the issue.

 

[Bouche Dag]

Theres no differance in ecus other than the pins and the BIN thats loaded. 91+ uses the E931 Bin while the 90's used like a E742. Just looked at my stock EEPROM. Im at almost 90% on 750CC FIC's on stock 14B. You need to see what ## IAT is. If its hot after IC its gonna cause ## IDC's to go up. For me that was on pump 93 im running E85 in the tank and even with the extra fuel im still about the same as 93 IDC's

The IAT is at 80*F which is what is standard for the maft.

I am seriously considering DSMLink. I'm hoping that will be a panacea for me.