Hey guys. I've done the research and know about the dead spot with these injectors, but unfortunately I'm a little green when it come to this aspect of tuning. I've read the Mega Manual and looked around here and the Bullet. The car runs and idles at about 1k, but like most guys upon install, the idle quality is crap. I'm pretty sure it has a lot to do with the "Injector Characteristics" settings I have in MS and was hoping to get some guidance from some folks here. The settings below are from my SD 83s.

Injector Open Time (ms) - 0.850
Battery Voltage Correction (ms/v) - .0160
PW Correction Limit - 30%
PWM Time Threshold (ms) - 0.9
Injector PWM Period (us) - 66

The idle with these settings was good, but I feel could have been better. I've since changed to e85 and in doing so installed the 160s. I'm "decent" when it comes to tuning the rest of the car, but my lack of experience with this part of the tune shows. I have a vague grasp of the concepts above, but putting them into practice is a completely different animal.

Currently I have the IAC disconnected and the EGO Correction disabled.

Any help with this would be greatly appreciated.

 

After doing more reading, I tried different settings in the IOT or dead time setting. I've read where some folks have had luck using injector dead time of 1.4-1.9ms. I went from .850m directly to 1.9ms just to see the affect. I have turned the idle up to 1k RPM using the TB idle adjustment screw. I flattened out the idle portion of my VE table as well. As suspected, the WB showed extremely rich to the point of blowing smoke out the exhaust. I set it to 1.5ms and noticed little change. I set IOT back to .850ms and the car would idle, but the WB was now showing very lean and then rich, highly erratic. I watched the real time display and noticed the pulsewidths stayed at 1.2-1.3ms and voltage was constant at 13.4v.

I listened to the exhaust and heard a distinct popping. Timing is set to and showed a constant 16*. Heads were just check and rebuilt so there's no burnt exhaust valves and the rockers are adjusted. I think the rockers could use a little touch up due to a slight amount of noise, but for the most part they're good. Hell, for all I know the chatter I'm hearing could be the injectors clicking.

Any help would be greatly appreciated.

 

How big is your cam?

 

F-cam. So it's a little fella.

 

This is something I found a long time ago...

https://www.theturboforums.com/threads/293110-Injector-Opening-Time?p=993671&viewfull=1#post993671

 

Thank you. I found that in my search as well. Gave it a much detailed read this time. Guess I'm going to keep "stabbing".

 

Well, I have some weird stuff going on now. I adjusted my idle screw up to about 1000-1100RPM. Put the Dead Time at 1.079. I left the Voltage Correction and all other settings the same. The car idles great. Unfortunately its at 10.9-11.1 AFR. Nothing I change in MS will make it run leaner. I've changed the fuel req and dropped the VE Table in the idle area to <10. I'm starting to think something is wrong mechanically or with my MS2 unit. I'm going to reinstall the 83s to verify it still runs as well as it use to with them. I'll post my findings.

 

Try reducing the number of squirts. If the injector cannot react quickly enough it could just be hanging open too long regardless of what you are commanding. Cutting number of squirts down will reveal if you can again induce change in AFR with changes to the VE table.

 

That was my next move. Going to go with what was said in the thread linked above.

 

Let us know how it works... That can also tell you if you dead time is close if it drastically changes the AFR when switching # of squirts.

 

That did it my friend! Started alternated between 1 and 2 squirts as the above thread mentioned. Got it to stay within .5 AFR using 1.075 IOT and .160 correction using 2 squirts alternating. Idles smooth at 1k RPMs and 13.2AFR. Gonna fool with it some more and see what it can take.

Thanks again everyone!

 

Awesome.