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ECMlink Help needed on first log... dumping fuel

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my97gsx

Probationary Member
10
2
Jan 20, 2019
HOPEWELL JUNCTION, New_York
I recently performed a few upgrades to my gsx; 16g - 255lph pump - Speed Density - and DSMlink. I believe i set up link properly for my setup, but had a big problem with it dumping fuel, especially on idle. I was running RC 550s, but once unable to control them I put the stock 450s back in. This attached log was my last start up, and as you can see i am still at a 9.0 afr... I am lost at this point. Can someone please review this log, and my settings - hopefully I am over looking something. Thank you in advance.
 

Attachments

  • 05.05.19 fuel dumping at idle.elg
    26.3 KB · Views: 55
...outside of the list of upgrades you provided, we don't really know much about your car. If you want sound advice we have to know EVERYTHING that you have installed (or don't have installed) to help you or it's the blind leading the blind. Create a build profile and update the list of mods you've got.


With that being said, what are you basing your AFR reading on? A wideband gauge? I'm going to guess you don't have an adjustable fuel pressure regulator and you're running the factory one?

Fuel injectors are rated at a specific fuel pressure, so what you're calling 550cc or 450cc injectors flow 550cc or 450cc @ 43.5psi, which is what the stock 2g fuel pressure regulator should maintain in the fuel rail at idle (what's referred to as base fuel pressure). If your stock fuel pressure regulator is being overrun by a 255lph fuel pump, which is considerably bigger than the factory pump, then odds are the fuel pressure in the rail is a lot higher than 43.5psi. Just to throw a number out there, lets say that the stock pressure regulator is only able to maintain 63.5psi (overrun by 20psi) because of the larger fuel pump. That means your RC 550cc injectors were actually flowing 665cc or your stock 450cc injectors are flowing 544cc. If you're wondering how I got those numbers, there's an equation but I don't know it so I use an online calculator. Fuel Vs Pressure Calculator ECMLink also has a similar calculator in the fuel tab, you just put your injector size in there and the actual fuel flow you're seeing at the rail and it will tell you what globals to run. I don't recommend doing this because it's a band-aid fix to get the car to idle properly but it won't help you when you start doing WOT since you want fuel pressure to rise 1:1 with boost. If the stock regulator is being overrun at idle, odds are it won't increase fuel pressure linearly 1:1 with boost like it should.

So, if you have a way to check fuel pressure in the rail, it should be reading 43.5psi with the car off. To kick the fuel pump on with the car off using ECMLink just turn the key to the on position, connect with your laptop, go to the Misc tab, and click the activate fuel pump button.
 
I can clarify some of the mods on his car, as well as the fuel pressure issue. The full mod list is as follows:

Stock 7 bolt engine, EvoIII 16g, Walboro 255, FIC FPR, RC550's, SD with Dsmlink cable, along with the usual 3'' exhaust and FMIC upgrades.

Fuel pressure was set at 43 as needed, but after the fuel dump it was lowered to around 38 (which did not help at all). Stock 450's were put back in just for startup, they also dumped fuel (monitored on wideband gauge 10.0-10.3 AFR).

I'm thinking there is an issue with the settings on link regarding the SD setup.
 
Front O2 sensor isn't cycling, try simulating narrowband on the rear O2. I can't find a logged MAP sensor so I can't track your SD table and that may be your problem also. Looks like you have a GM 3bar but I cant seem to get it to display so you need to assign it and capture it if you aren't already. I can't see everything because I am at work and running link which is very tricky for me to do.
I don't see your IAT either.
 
Here are some screen shots of a E85, SD, 1120's for setup purposes. They may not be applicable for you but if you follow along, it should get you the inputs that you need for the ECU to know what to do.
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These were before I manually set my TPS, which is always a wise thing to do and get it as close to perfect as possible then adjust it in link.
 
Here is why I said that. According to the pin assignments, the Wideband is tied into the rear O2 sensor input.
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I run mine in the front location and simulate the narrowband operation.
 
Thanks for the replies. After more research I definitely think the speed density conversion was botched in the program on my end. We never designated the baro sensor. So ecu is only partial information. I'm using an autometer wide band in the rear but it doesn't put out a narrow band signal. So do I use the front o2 sensor as the narrow band? New to this. I think I was over zealous to get the thing started and didn't do my due diligence in setting up SD properly. I will attack it this week and post up a new log.
 
I have never fooled with an Autometer wideband (love my Inovate LC2) but if it can't simulate then you need the front O2 sensor to cycle. When it is working, the ECU adds fuel then takes it away as the sensor cycles.
Do some more research and set up what you can then hit us back with a new log. :thumb:
 
Use this to help you get setup properly, I know it's titled for a 1g but 99% of it applies to 2g as well.
 

Attachments

  • TUNE_1G_V3_SD_ECMLINK_NOMAF_1.5.pdf
    498 KB · Views: 135
There ya go!!!
Thanks Corey! :thumb:
 
Alright made some adjustment as per your recommendations. Made a few logs. The car idles a bit rough but less rich. Plugs are toast... thinking my front o2 sensor is shot. Please take a look at my logs and let me know your thoughts. Thanks.
 

Attachments

  • log.2019.05.09-03.elg after adjustments.elg
    119.6 KB · Views: 50
  • log.2019.05.09-04.elg with 02 simulation.elg
    140.8 KB · Views: 43
Need to assign the omni 4 bar MAP sensor to the Baro input. 02 sensor isnt cycling. Log Short term fuel trim and Long term fuel trim. LoadScale should be put back to 100% in direct access. "Use manifold pressure (MAP)" box needs checked in MAF Clamp tab. Your Max timing map should be more like the picture, but all are different. The timing map you have looks like one of mine when I had a No KeyStart signal. This map is just a random map, someone with a stock map, or a stock timing map will work better for you.
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Just a few things I see before logging out for Mothers Day. Check them out. Anyone, please correct anything that I may have overlooked or given any misinformation.
Hug your Mom today, everyone. Mine taught me how to chg plugs and oil and a million other things!
Thanks Mom, HAPPY MOTHERS DAY!!! :pray: :)
Marty
 
Last edited:
Just wanted give an update. Found my crazy idle surge was caused by bad seals on old 1g throttle body. I will be rebuilding it and it should smooth out. My 2g throttle body installed on the car smoothed things out. Cams are in and will have it dyno tuned next weekend! Thx for the help.
 
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