Extremely lean idle after 850cc injector install...

[AngelOfPassion]

Just finished installing FIC 850's and wanted to make sure the car would run before tackling installing my 190lph fuel pump.

When I start the car it behaves almost as if you unplugged the TPS or if you unplug your front o2 sensor. It starts just fine but my wideband reads an af/r of about 22.0 to 22.4 while the car is idling. When I give it some gas to rev it just hesitates and barely is able to rev. The air fuel ratio never gets on track, it just stays around 22.0...

It looks like the injectors are not leaking, I kept the car idling as I looked in with a flashlight and couldn't see any fuel spewing out.

I followed the instructions to the t, made sure I plugged everything back in correctly and dialed in my injectors in ECMlink to -47.3 percent global fuel and 330 usecs deadtime.

What do I need to check here?

Instructions I followed for reference: Injector removal and installation

 

[WES_393]

Do you have any way of reading fuel pressure? Are the injector clips tight and dry? Did you wiggle a connector loose or forget to plug one back in, such as the PTU on the intake manifold?

As I'm sure you know, those settings are just a good starting point. You'll usually need to make adjustments in order to get everything dialed in. But you shouldn't be anywhere near 22:1

 

[AngelOfPassion]

I don't have any way of reading fuel pressure but everything is plugged in. I upped the global fuel to -30 percent and the car idles at 14.7 ish but is pig rich at WOT running at about 9.5-10.0 afr.

I don't feel like I should have to up the global fuel that high just to get the car to idle correctly though...

 

[WES_393]

Then I would leave global at -47% and try messing with just Deadtime. It's my understanding that Global effects the entire RPM range pretty equally, while Deadtime adjustments become less of a factor as RPM's raise. If that makes sense.

 

[AngelOfPassion]

At -47 percent global and 700 usecs of deadtime I get an idle jumping around 14.5-15.0

Sounds like it might be missing a little bit as well. I don't know if that is just how it is with larger injectors at idle or if it is abnormal...

I still think that is a major change from what it is supposed to be by changing the deadtime that much haha. Any other ideas or should I just leave it like this?

Oh, and the Whinebro 190lph is in there now as well btw...

 

[jed344]

Your car will be rich at wot dead time and global has no effect on wot. My car also will sound like it misses every now and then at idle with fic 1050cc.

 

[dsmAB]

I just had almost an identical problem. Finally resolved it today. If you had evo injectors before, you adjusted the InjBatteryAdj for it. Set them back to stock and it should be fine.

http://www.dsmtuners.com/forums/ecmlink-tuning-log-file-advice/469103-fic-850s-have-dialed-780s-car-run.html

 

[camas90gsx]

What about a possible exhaust leak before the wideband bung? It seems stupid,but it could be as.simple as that. I had a leak at my external wastegate,and my a/f readings were similar. Just thought id throw out the obvious. Also,what are your 02 readings looking like?

 

[AngelOfPassion]

Your car will be rich at wot dead time and global has no effect on wot. My car also will sound like it misses every now and then at idle with fic 1050cc.

You sure? It was doing the exact opposite last night. With global higher it would run pig rich at wot but with global at negative 47 and higher usecs of dead time it would be normal at wot.

I just had almost an identical problem. Finally resolved it today. If you had evo injectors before, you adjusted the InjBatteryAdj for it. Set them back to stock and it should be fine.

I've never had any other injectors besides stock since getting ecmlink but where do I check that value and what is it supposed to be set at for stock?

What about a possible exhaust leak before the wideband bung? It seems stupid,but it could be as.simple as that. I had a leak at my external wastegate,and my a/f readings were similar. Just thought id throw out the obvious. Also,what are your 02 readings looking like?

Wideband is put in where the front o2 was. Really hard to get an exhaust leak pre wb but I guess it's possible. Idk though.

Edit: Another thing that is weird that I am noticing is the ecu will not cut fuel when I am decelerating like it normally would. I get about a 17/1 afr when I let go of the gas in gear... Don't know if that has to do with anything...

 

[97gsxIA]

Your car will be rich at wot dead time and global has no effect on wot. My car also will sound like it misses every now and then at idle with fic 1050cc.

Global fuel adjustments most definitely have an impact on WOT conditions. In fact some people (including me now from a mishap I had during WOT tuning) set their global by locking the ECU in Openloop (which is what your car runs in WOT) and then adjust the global accordingly.

OP: Where did you buy these injectors? Brand new from an FIC distributor? Taking your foot off the throttle and not getting a pegged lean condition makes me think your injectors are not shutting off like they should be.

Are you throwing a CEL?

 

[AngelOfPassion]

Brand new FIC's from ExtremePSI... No CEL's at all, even when I hadn't adjusted deadtime yet and was idling at 22/1.

If I am at like 6000 RPM and let my foot off the gas, after about 2-4 seconds the car will lean out to 22.4. It's just not instantly like it used to be. Under normal deceleration while downshifting it never gets a chance to fully lean out because I will downshift into the next gear before it ever fully cuts fuel...

 

[dsmAB]

You can check the values at the direct access tab. If you never changed the values for the InjBatteryAdj it should be stock already.

 

[AngelOfPassion]

I've been reading on the ecmlink wiki and I have found a section about idle tuning. I am going to try to see if tuning the idle a bit can help me get my deadtime back down a bit. We'll see if that helps the issues I am having.

 

[IrishBeatdown]

Angel, I am having the same problems you are, just have a little different tuning input than you as I am using ECUflash. My car starts just fine, then idles poorly and hesitates when you give it gas. My wideband shoots to 22 pretty quickly after the wideband warms up, so I have been turning it off as to not idle it when it is running so lean. The only thing I could add is that as to the stark similarity of our issues, I can say your fuel pressure is likely fine. I have an AFPR that reads a perfect 43psi pressure, and my car behaves exactly to the T as to what you have described. I hope you get it figured out, I'm going to follow this thread, and hopefully once our cars are through trying to burn holes in our engine internals we can meet up at tempe town lake.

 

[WES_393]

Angel, can you post up an idle log?

When it comes to deadtime, there's really no "correct" number. From the ECM Tuning wiki:

The ECU assumes a nominal 700 microseconds of injector deadtime (for stock injectors). The Deadtime adjustment value is the number of microseconds added to that to compensate for injectors that react more slowly than stock injectors. Typically, the larger the injector or the higher the fuel pressure, the greater the injector's deadtime.

The Deadtime adjustment value usually needs some tweaking to get actual air/fuel ratios to match what the ECU intends. Since the Deadtime adjustment value is added to the injector pulsewidth, altering it tends to change the actual air/fuel ratio mostly at idle and very little at wide-open throttle

So as long as your fuel trims and AFR's are in check, then I wouldn't worry too much about the deadtime value itself. Your throttle issues are likely within the tune, not an issue with the base settings. And for what it's worth my FIC 1150's use a deadtime of 600. The engine will barely run with the recommended 330.