2G HELP! FIC 1120cc DSMLink Idle RPM Problems

[1slowhatch]

Today I installed new FIC 1120 injectors in my 2g dsm. Stock fuel system otherwise. The car runs great with the stock 450cc injectors.. I do have a WB in the car. With the stock injectors, the tune is close. Idles at high 14's, under boost it seems right (stock timing and fuel tables.. high 10's under boost). Combine FT are relatively low at warm idle on the stock injectors. I swapped in the FIC 1120's.. I've tried the recommended -60% global settings and matching the injbatteryadjust chart to what came in the box. It idles very high, surges some, and afr est is off, comb fuel trims wayyyy off.. WTF is going on? Bad injectors? Vacuum leak somehow on new seals/injectors?? I tried leaving the injbatteryadjust chart alone, and adding around 330 deadtime, still runs terrible.

With the old stock injectors everything was close.. afr estimate was within a few .1, commanded RPM was almost perfect, never surged, idled smooth..

 

[1slowhatch]

Also, I've searched and found several threads... with no resolution..!? I hope it's not these injectors having a problem..

 

[1990TSIAWDTALON]

On gas with my 1120's in my 1g I was running -59 global and 80 for my deadtime. Once it is running you can play with the deadtime for your application if it needs to be closer on your afr's. Just tryin to help. I am on E85 now and running 1650's. Hope it helps.

 

[Mitsuridr]

Play with dead time and mafcomp 50 hz slider until you get your .24-.27 airflowperrev and combinedft as close to 0 as possible. I only have rc 550cc in my car, but had similar issues after installing them. It took some serious adjusting back and forth for some reason, but just playing with it helped a lot. I had to run my mafcomp adjust again after just for peace of mind...it changed a little. As far as global, that is not that dead set either. Once I put some miles on the new injectors I checked out my low and mid fuel trims and in order to get them in line as close to 0 as possible I ended up with a -14.8 value instead of the reccomended -18. My injbatteryadj tables are stock. Just play around with it man and no matter how frustrating it may seem, you will get it.

 

[1slowhatch]

Play with dead time and mafcomp 50 hz slider until you get your .24-.27 airflowperrev and combinedft as close to 0 as possible. I only have rc 550cc in my car, but had similar issues after installing them. It took some serious adjusting back and forth for some reason, but just playing with it helped a lot. I had to run my mafcomp adjust again after just for peace of mind...it changed a little. As far as global, that is not that dead set either. Once I put some miles on the new injectors I checked out my low and mid fuel trims and in order to get them in line as close to 0 as possible I ended up with a -14.8 value instead of the reccomended -18. My injbatteryadj tables are stock. Just play around with it man and no matter how frustrating it may seem, you will get it.

I appreciate the response. I believe I'm getting right around .24 airflowperrev now.. Is it normal to see the idle speed wayyy higher than it should be? Do I need to work on getting the idle speed closer to what it should be first, then looking at airflowperrev? IE Mess with fuel settings until I get the speed closer.. then mafcomp... then fine tune fuel until the fuel trims are low??

 

[Mitsuridr]

By idle speed are you talking about your rpm? If so then yes you should get that to whatever your targeted idle rpm is in link. Make sure you don't have any vacuum leaks or anything and your logged isc position is 30 once fully warmed up. Also make sure your idle switch is working properly, best to just simulate it. If those are good you should be hitting your targeted rpm. Then yes mess with fuel settings to get your trims close. How much higher is your idle?

 

[Vegas Smith]

Check those injectors seals. I swear those things will leak air and you could never tell by looking at the fuel rail.

 

[1slowhatch]

Check those injectors seals. I swear those things will leak air and you could never tell by looking at the fuel rail.

How should I check them?? A boost leak test would tell me, right?

Any tricks to install to prevent leaks?

 

[1slowhatch]

By idle speed are you talking about your rpm? If so then yes you should get that to whatever your targeted idle rpm is in link. Make sure you don't have any vacuum leaks or anything and your logged isc position is 30 once fully warmed up. Also make sure your idle switch is working properly, best to just simulate it. If those are good you should be hitting your targeted rpm. Then yes mess with fuel settings to get your trims close. How much higher is your idle?

Actual idle speed is wayyy off from commanded. Like more than 700 rpm higher.

 

[Mitsuridr]

Did you install new injector bushings with the new injectors? Like the doughnut ones that go on the head at the bottom of the injectors. If not then I would suspect a leak from there for sure. Those things get hard as a rock when old and will never seal right especially when installing a completely different injector. That would be a giant vacuum leak depending on how much air is getting past them if that is the problem. You can get some brake clean with the hose on the can for a more direct spray and with the vehicle running spray some around where the injectors seal around the head and if your idle changes then you have a leak from there. The brake clean will temporarily form a seal around the bushing which is how the idle changes. This could also be the cause for your funky fuel settings.

 

[1slowhatch]

Did you install new injector bushings with the new injectors? Like the doughnut ones that go on the head at the bottom of the injectors. If not then I would suspect a leak from there for sure. Those things get hard as a rock when old and will never seal right especially when installing a completely different injector. That would be a giant vacuum leak depending on how much air is getting past them if that is the problem. You can get some brake clean with the hose on the can for a more direct spray and with the vehicle running spray some around where the injectors seal around the head and if your idle changes then you have a leak from there. The brake clean will temporarily form a seal around the bushing which is how the idle changes. This could also be the cause for your funky fuel settings.

Yes, the injectors were brand new and came with brand new "blue" donuts for the bottom. I'll try the brake clean test in a little bit.

 

[Mitsuridr]

For sure. If they are brand new then hopefully that's not the problem. Make sure your isc position is good, hopefully it is if it idled fine with the old injectors. Just set the global for suggested and play with deadtime until combinedft is good. Maybe reset Mafcomp to get back to a good starting point just to rule everything out. I know that doesn't really have anything to do with idle, but I actually tuned my mafcomp around an unknown leak and once it was fixed I had to readjust it. Not saying that is your problem, I'm just trying to help cover all the bases here. I understand the frustration with idle issues. It's good just just recheck everything. Is the idle rising as the engine warms up, or is it just always steady 700 or so high?

 

[Mitsuridr]

Sorry to double post, but I'm having thoughts pop up here. I had a problem where once i put in the bigger injectors I had to raise deadtime alot to get the front o2 to start cycling for some reason. Did you make sure your car is achieving closed loop after 15-20 seconds?

 

[1slowhatch]

For sure. If they are brand new then hopefully that's not the problem. Make sure your isc position is good, hopefully it is if it idled fine with the old injectors. Just set the global for suggested and play with deadtime until combinedft is good. Maybe reset Mafcomp to get back to a good starting point just to rule everything out. I know that doesn't really have anything to do with idle, but I actually tuned my mafcomp around an unknown leak and once it was fixed I had to readjust it. Not saying that is your problem, I'm just trying to help cover all the bases here. I understand the frustration with idle issues. It's good just just recheck everything. Is the idle rising as the engine warms up, or is it just always steady 700 or so high?

Ok, so I just did a boost leak test. I found a medium leak at a boot and smaller leak at another boot. Injectors seem to be sealing up fine... Only other boost leaks were small (pcv, biss screw).

I figured out the high idle. The throttle cable wasn't bolted down and was apparently hung up. I fixed it, and bolted it back down, got the idle much closer. I followed the ECMlink vids to dial in the injectors. I had to mess with maf comp a little 0-100hz to get it to show 25ish airflowperrev. Then I started messing with dead time until the o2 started cycling. I ended up leaving the voltage dead time chart to stock settings, but adding more dead time than recommended (over 500). I now have a pretty good idle, combined ft of around -1% to +1 %, afr estimate at idle is pretty close to wideband readings..

Going to data log a cruise and see how it does. I appreciate all the help.

 

[Mitsuridr]

That's awesome man I'm glad to hear you got it figured out and glad I could help. I was gonna say something about the throttle cable with the high idle, that's good that's all it was! Hopefully everything starts to line up with your fuel trims. Once I started driving and checking it is when I realized I had to adjust my global different then what was recommended and it actually brought my dead time back down to around what it was supposed to be. Good luck!

 

[fabian95tsi]

I am currently running these same injectors I am currently on e85 but I still have some old logs and settings from when I was on 91pump...I am also on speed density but when I had first gotten my tuned self tuned, my global fuel was -57 and dead time at 470 this was on the stock intake manifold and stock motor...now this time around on my built motor and jmf race intake manifold I had it professionally tuned. My tuner does not use deadtime and my settings are -45.7 and 0 deatime...car idles perfect I believe my tuner only uses the sd table and another setting in direct access...but that's what worked for me.

 

[Mitsuridr]

Hmm I'd be interested to know what he changes in order to run with 0 dead time on that big of an injector. Never heard of that before. Whatever works though right!

 

[fabian95tsi]

The biggest change I've seen from how I dialed in my car how he did it was in the sd table, I need to look into the direct access area and see what else he did. I had a good grasp on how to tune until he started messing with my car, but it runs great and have no complaints

 

[1slowhatch]

I am currently running these same injectors I am currently on e85 but I still have some old logs and settings from when I was on 91pump...I am also on speed density but when I had first gotten my tuned self tuned, my global fuel was -57 and dead time at 470 this was on the stock intake manifold and stock motor...now this time around on my built motor and jmf race intake manifold I had it professionally tuned. My tuner does not use deadtime and my settings are -45.7 and 0 deatime...car idles perfect I believe my tuner only uses the sd table and another setting in direct access...but that's what worked for me.

What turbo are you running? Any insight on E85 tune up for a 16g 2g car? I'm considering filling up the tank and trying to self tune. It looks like global fuel should be easy enough to modify with one of those ethanol content charts. What about timing? I hear taking a stock 2g timing map and adding a few degrees in the high load areas will get me close?

Or just crank up the boost controller and see how it looks? I hear around 12:1 on a gas scale is good to shoot for WOT.

 

[fabian95tsi]

I'm running a fp hta green, my global fuel went from -47 to -34...min/maxoct tables were changed, there is a calculator on ecmlink.com to help you your global settings. I actually started off by using my 91 map and changing global fuel...my car actually fired right up, from there my tuner took over. I would keep the car at around 15psi or so to start after you get everything set up, idle and cruise then I would start with some wot pulls. As far as timing that is a little tricky. But mines at 17 degrees up top. I would start with something low like 12 or so and go from there. Afr in full boost my sees 12.0-12.4... others might recommend 11.8-12.0