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VE at idle too high??

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Hello, I have a link G4X on a 1jz vvti, 1000cc injectors, gt35 top mount turbo. I finally got my car up and running today, haven’t done any tuning yet as far as actually putting load on the car but I played with the VE table to get it to get around 1.0 Lambda at idle (1000-1100rpm) at -50kpa and the numbers in the VE table seem too high to me. Around idle it’s at 85.3 VE. I did rev it up and at 2000rpm and -60kpa it’s 75.8VE 1.0 lambda. Maybe I’m just still not fully understanding everything after doing the practical standalone courses and watching numerous webinar, but any help would be appreciated.

Are you sure the injector deadtimes (injector latency) has been entered correctly. Latency values that are too low, will show up as larger VE values especially at low pulse widths (like idle).

Also, are you sure your O2 is reading correctly? It's sometimes difficult to get a good reading at idle -- does the O2 reading change if you put your hand over the exhaust pipe to prevent fresh air from being sucked in?

Honestly I have no clue if the latency info or even flow data is correct, the injector company (snake eater performance) sent me data that I tried to translate over to work on my link ecu but I don’t know if any of it is correct or even able to use. They sent me GM/Ford/Chrysler injector data, I asked for different info and they sent me the same info as before. I ended up using differential fuel pressure and a FP sensor in hopes that their info would work still. I may have messed up bad by not just getting ID or FIC injectors.

And I’m fairly confident my o2 is reading correctly (link can lambda), I also have a wideband afr gauge down stream of it and getting the same/similar afrs. But I will try putting my hand over the exhaust and see if anything changes.

I have attached the injector data in case that might help. I feel like the flow data they sent, and the “plug and play” data they sent doesn’t match up very well. It could very well be my lack of understanding too though.

Attached Files

The more I look at that data the worse it looks... Im not sure I would trust any of it. On the paper printout their "dead time graph" is exactly the same as the flowrate graph? The flowrate Vs duty/PW graph doesnt look real at all, it is never a straight line like they show, it will usually have a near-vertical bit around 90%DC when the injector doesnt have enough time to close. In the excel sheet the "Flow Graph" I don't even know what that is showing, the 0-8 on the X axis might be PW, but what is the 0-100 on the Y axis? The flow rates in the excel sheet are about 20-30% higher than the quoted flow rate on the paper sheet...

FYI, here is how a real flowrate Vs PW graph usually looks, notice flow sharply rises then flatlines at about 18.5ms (~95%DC):

Okay I’m happy I’m not crazy looking at it. I’ve been comparing it to FIC data and ID data and noticed pretty much exactly what you’re saying, you just put it into better words than I could. I don’t think the flow is even remotely correct, I searched the Bosch part number on the injector (0280158321) and I’m finding they’re rated for 500 g/min. I do believe they’re modded/decapped, but I’m doubtful they’re even close to 1000cc the more I’m looking. I think I’m just going to try to get my money back and go with something actually reputable for injectors. Definitely a case of “you get what you pay for.” Thank you for the help Adam!

Attached Files
  • 4628E549-A305-4808-8C9E-D956977AB1EF.jpeg
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Could it also be a problem with incompatible impedances? If the drivers are for low, and the injectors being high(?), there may be a issue with the opening for the short period required?

The Link ecu uses high impedance injector drives. From the website for the injectors it says they're 12.5 ohm high impedance, but with the rest of the data they supplied that could be completely wrong as well. Haha!

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