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Continuing this on from my earlier thread. E40 ECU, LS1 with an LS2 intake and 90mm throttle body. Turbonormalised (No real boost). I changed the VE table a few times, but made it worse, the thing is really lean, headers glow when idling and it's hard to keep running, STFT goes to 27 to make it managable. Strange, the log shows the injector only opening at 4 percent or so. I am really lost here, tried moving the whole VE table richer (?) 10%, either way and it only got worse. Anybody please?
Cant view the log on my home Mac. If your headers are really glowing at idle then your timing must be a looong way off or some sort of sensor issue - what is the timing doing??
Spark timing doesen't seem to be too far off, but sometimes at a full idle it will go past TDC, a negative number, say -5 or so. But no matter what, the thing is very lean, to the point that I don't want to run it anymore for fear of screwing up the motor mechanically, not to mention what it does to my gearbox and prop when it idles rough.
This just start or have you never had it running correctly yet?
Very Lean!!!!
Idle fluctuating, settles a bit to around 950 yet you have max idle set at 800
Timing stablizing at -5.5 (because trying to get idle down to 800? this will can also cause headers to glow, that and being lean)
Possible vacuum leak?
Possible TB issue? (again, is this a new problem or has it always done this? )
It's always been lean. Engine and installation is all new. I was supplied the harness and ECU from a harness shop in CO, so the tune wouldn't be right, he just put 'something' in there to get me going, which it did, but it's not close. Everything except the ECU is new, I did change the intake manifold to an LS2 style to use the 90mm throttle body to go along with the E40 ECU, but I don't believe it has any vacuum leaks. Has a large (1.48 A/R) turbo just behind the MAF, but it shouldn't be using the MAF at idle and low speeds yet, right?
Motor is set up to be turbonormalised, so won't make any boost ever, but maintains sea level pressure at the MAF up to 29,000 ft. At ldle the turbo might be a slight restriction, but can't imagine it would change things this much. Headers are large 2" tubes and the whole exhaust system might make it go leaner because of decent flow, but still...?
Stock injectors?
I think the timing is low because it is trying to bring idle down to 800, could raise it to 1000 and see if it is better, may help to isolate issue.
I am just a newb at this as well, and could be way off.
Just trying to learn but reading the forums.
Yes, stock LS1 injectors in the LS2 intake. I wondered if the spark timing is retarded trying to keep it running. I played with the VE table but didn't really know what I was doing, with that tune I couldn't keep it running, stalled constantly, so I went back to the original tune. The last one I copied a VE table from a 2005 GTO, and that would keep running, but still lean.
The A/F ratio is set to 14.7, I thought about dropping this down as a temp fix, but again, don't have any idea if that would change it.
Just had a thought. This aircraft has no transmission that the ECU knows of, on the log it shows zero MPH. Could this engine be operating, or trying to run, in DFCO mode? If so, how do I disable it, maybe change the speeds it is enabled or something?
Bump for this, I am desperate, PLEASE check out my log and tune, getting nowhere with this and scared I may melt the whole engine down if I just keep at it myself.
it does seem like there's an air leak... add 30% across your VE table if your SD just to see what happens to the fuel trims.. if they balance out, then your fueling is off, could be the injectors are for something else?
Also take a look at your Open loop eq ratio.. set those values to 1 in Gas gear and P/N.
Thanks for the response. Still being a newbie, you say to add 30% to the Main VE, primary table? So I would increase the numbers there, correct? I do have the MAF installed, and working, but when it works I haven't figured out yet. The injectors are the original, new ones that were in the LS1 intake, on this engine as I bought it from GM years ago. Note the log, they only ever open 4%, even at 2000 rpm. Seems low to me, and the only way to get more fuel is to open them longer.
The open loop EQ ratio maps are set to anywhere between 9.00 and 10.00, way off??
I had asked before if there was a possibility that the engine was trying to run in DFCO mode. This aircraft has no transmission that the ECU knows of. So I went in and looked, seemed to me that all the conditions for DFCO were enabled, so I bumped everything up so it couldn't go there. Well, this was MOST of my problem. I attached a log of it and the tune. Although it's still lean, at least the headers aren't glowing red now, and it will idle somewhat at 800, and rev up as it should. SO, for anyone who runs an E40 ECU, a race car without any trans electronics, you HAVE to disable the DFCO or it will try to run with it permanently enabled. Thanks to planethax and trailblazin for their help.
what are you using for your fuel system? is it a return style or returnless?
- timing is why your headers are glowing get the idle timing in the 20 s and then see what the fuel mixture is. Chances are it is not lean. You are seeing unburnt fuel go past the wb because it is trying to ignite so early. The you get combustion leaking past the exhaust valve, and superheated air on the exhaust stroke lighting up the headers.
Fuel system is a return type, with the regulator on the return hose at the tank. Uses a Bosch pump from a 911 turbo Porsche. have a guage at the fuel rails and shows 58 psi all the time, without any load.
The timing is all over yes, but with DFCO enabled the injectors never went over 4% no matter what I did. With it disabled I now see 8% or so just free revving it. I haven't had a chance to put the prop back on and take it out and load it yet, I have to work on the whole project and have other issues as well. I think it is lean as the STFT goes to +28 as soon as it can, and when it gets past 10 or so the motor starts to come alive. No idea what the spark timing should do though.