$0D TBI to MPFI conversion, how is your idle quality?

**96lt4c4** · 10-17-2014

I have done all the necessary changes in the bin and the mod to the PCM. My idle seems to be a tad rough, almost like a miss. I installed a new cap, rotor, and MSD wires while I had it apart. The truck starts great and runs good other then just a slight issue at idle. Just wondering if there is something I missed in the tune. The injectors are stock LT1 with about 60K miles on them running at stockish LT1 fuel pressure 40-43 pounds. I have not had a whole lot of time for tuning a logging. I am going to hook up a vaccum gauge this weekend and maybe readjust the valves to see If I can find anything there.

The truck has always had a wierd issue that I cant seem to figure out, where Acceleration Enrichment activates at idle randomly. I maxed out the MAP qualifier to enable AE at idle and it still does it.

Here is a copy of the current bin I have been playing around with.

**Fast355** · 10-17-2014

Originally Posted by 96lt4c4

I have done all the necessary changes in the bin and the mod to the PCM. My idle seems to be a tad rough, almost like a miss. I installed a new cap, rotor, and MSD wires while I had it apart. The truck starts great and runs good other then just a slight issue at idle. Just wondering if there is something I missed in the tune. The injectors are stock LT1 with about 60K miles on them running at stockish LT1 fuel pressure 40-43 pounds. I have not had a whole lot of time for tuning a logging. I am going to hook up a vaccum gauge this weekend and maybe readjust the valves to see If I can find anything there.

The truck has always had a wierd issue that I cant seem to figure out, where Acceleration Enrichment activates at idle randomly. I maxed out the MAP qualifier to enable AE at idle and it still does it.

Here is a copy of the current bin I have been playing around with.

IAC AE??

**96lt4c4** · 10-17-2014

My upper threshold for IAC AE was 3.9, the stock bin from my truck was 2.3? I compared my bin to one that I had found from a 95 Z71 years ago, AIXZ, I changed it back to my stock setting.

**96lt4c4** · 10-18-2014

Looking through some CPI bins, and notice the have Synchronous Idle set, I thought that was TBI only?

**JeepsAndGuns** · 10-19-2014

Its been so long since I installed my MPFI system, I cant remember what my idle was like before. It does kinda sound like it has a larger cam in it, semi chopy like a bigger cam. But its a comp cams 256XE, not realy crazy. I really like it, I get lots of comments about how good it sounds. So it doesnt really bother me. I have idle set for 650 rpm.
This is also on a AMC 401, not a chevy engine, so its gonna be different.

**dave w** · 10-19-2014

I had to make adjustments (trial & error) to the Async parameters to get a good $OD MPFI idle.

dave w

**EagleMark** · 10-19-2014

I've had the same AE issue at idle... try adding 50-100 more RPM...

**96lt4c4** · 10-20-2014

Originally Posted by JeepsAndGuns

Its been so long since I installed my MPFI system, I cant remember what my idle was like before. It does kinda sound like it has a larger cam in it, semi chopy like a bigger cam. But its a comp cams 256XE, not realy crazy. I really like it, I get lots of comments about how good it sounds. So it doesnt really bother me. I have idle set for 650 rpm.
This is also on a AMC 401, not a chevy engine, so its gonna be different.

This is the cam I have, really has no chop to it at all. Idle was pretty smooth with the TBI, now I have just a tiny issue that feels like a miss.

http://www.lunatipower.com/Product.aspx?id=1982&gid=287

I gave it some more timing at idle, that helped some. Idle is set to 700 RPM right now. My vacuum on the gauge is around 18 inches, about 40 KPA while scanning. I checked the plugs and they look good. I did have a drivers side header gasket leaking so I fixed that today because my wide band was showing a tad lean. I need to do a free air calibration on it as well. The truck runs really good, and the idle issue is not real bad either but its there now and wasn't before the swap. It almost has to be something in the .bin. I have played around with the idle over and under speed tables as well as the proportional idle tables and nothing seems to be helping it.

**96lt4c4** · 10-20-2014

I was having problems emulating with my Autoprom, its been so long since I have even used the emulate feature that I may be doing something wrong. I am going to play with it tonight and see if i can get it working again. I will play around with pulse width/async settings and see if i can get the idle to change.

**96lt4c4** · 10-21-2014

I cant get my autoprom to emulate, I have disabled the checksum, the bin verifies when its uploaded. Its been a while since I used this feture but its always worked in the past. I have the newwst version of Tuner Pro, that's really the only thing that's changed. Am I missing something?

The same bin burnt to a chip works in the PCM, but when uploaded to the emulator I get limp mode, SES on solid, short fuel pump run...etc

**JeepsAndGuns** · 10-21-2014

Stupid questions... Do you have the chip adapter/cable installed correctly? Are you clicking enable emulation before turing on the ignition switch? After limp home mode get tripped, are you unhooking power to the ecm to clear the memory/codes?

**96lt4c4** · 10-21-2014

Originally Posted by JeepsAndGuns

Stupid questions... Do you have the chip adapter/cable installed correctly? Are you clicking enable emulation before turing on the ignition switch? After limp home mode get tripped, are you unhooking power to the ecm to clear the memory/codes?

Yeah, this isn't my first rodeo. No chip in the socket on the autoprom, pin 1 on the cable is in the correct location, tried both ways just to make sure. Upload bin to emulator, verify bin, start emulation, turn on the key, solid SES light. Thats one of the major pains when this happens is unplugging the the PCM to reset it. I even tried a bone stock bin to see if it was something in my tune and no go.

Here is the bin I am working with now.

**JeepsAndGuns** · 10-22-2014

OK, was just making sure. I just know how we can get our minds on one thing, and forget small but important details about other things. Lord knows I do it all the time.
Have you tried calling moates? I suppose there is a small chance something could be wrong with the autoprom. I'm sure they would know the best way to trouble shoot.

**1BadAction** · 10-22-2014

Originally Posted by 96lt4c4

I cant get my autoprom to emulate, I have disabled the checksum, the bin verifies when its uploaded. Its been a while since I used this feture but its always worked in the past. I have the newwst version of Tuner Pro, that's really the only thing that's changed. Am I missing something?

The same bin burnt to a chip works in the PCM, but when uploaded to the emulator I get limp mode, SES on solid, short fuel pump run...etc

Switches on the APU are incorrect or the drivers on your computer are fukt. Delete and reinstall if you check and the switches are right. Don't install the latest FTDI drivers, there is something wrong with them, install the ones on Moates site.

**96lt4c4** · 10-22-2014

I have one of the very first versions of the Autoprom, the inner switch is vertical instead of horizontal, checked my switches setting last night and they are correct. I will check the drivers.