idle a litle rough?

[CDeeZ]

Most of you already know that I swapped from the '747 to the 427 PCM recently. Thanks to the help of those who inhabit this forum, I was able to get up and running on the '427 PCM.

Now I made some logs and adjusted VE using dave's spreadsheet and things were starting to look decent, but I have decided to start over on tuning the VEs for the two reasons below.

First, I wanted to see if I could get away with a higher injector flowrate since I have always been pretty rich at idle after the '427 swap. And also, My VE tuning that I had done, I forgot to turn off DFCO and PE when recording BLMs, so I think my data was inevitably skewed.

I raised my injector flowrate (again) from 69 to 74 lbs/hr, and pasted the stock fuel tables back in and proceeded to collect BLM, this time with PE and DFCO OFF. After one run of logging BLMs, my highest BLM was 127 and lowest was 110.

Now after several rounds of using daves VE spreadsheet, this thing runs and pulls STRONG with the engine loaded.

My question for today pertains to idle: At idle, the BLMs are around 110-117. When idling, the engine is a little more choppy than I think it should be, especially given that the cam is just under .5" of lift. Also, on startup sometimes the idle will fluctuate pretty wildly, then settle down. During idle, my transmission seems to make what is known as "neutral rollover rattle" which is totally normal to a manual transmission, but, I wonder if my rich and therefore choppy idle is responsible for making this more noticeable? When I was running the 747 the idle was very smooth and you didn't hear the rollover rattle as much. I think the rough idle caused by the being rich is what is causing this exacerbated rollover rattle.

And BTW to determine if a noise is in fact neutral rollover rattle, you can "float" the noise out by revving up the engine a little bit, and this is my case.

How should I go about cleaning up the idle manners of this thing? Try an even higher injector flowrate? Or slew down then entire VE area responsible for idle?

I'm posting the datalog I made tonight, you can easily see the idle fluctuation I'm talking about at the beginning of the log. Would someone please take a look at this and tell me what they think??

[gregs78cam]

At the end of that log while at an idle you are still at right around 1.00ms PW and BLM says the VE table is rich. So you still have room to take fuel out of the VE table. You should easily be able to get down to around 0.60ms PW before things get unstable. What are your IDLE VE table values in the area that you idle in?

I would also say to flatten out the SA in the idle SA table right around idle, that should smooth out the idle by not making SA jump all around. Your SA is anywhere between 4 and 16 at idle and IAC steps are just as bad. Those two items should almost be rock steady.

[EagleMark]

The little bit of idle in beginning of log looks bad... most in open loop and RICH. Look at O2 data in .900 to .800 range = rich... First thing is temp at 100C is 212 F is high and could be adjusting for it in bin. Second is MAP, RPM and Spark are rocking back and forth so bad your entering AE, may need to raise idle some for cam, steady spark timing by leveling it out and even raise it some, lean out VE...

[CDeeZ]

At the end of that log while at an idle you are still at right around 1.00ms PW and BLM says the VE table is rich. So you still have room to take fuel out of the VE table. You should easily be able to get down to around 0.60ms PW before things get unstable. What are your IDLE VE table values in the area that you idle in?

I would also say to flatten out the SA in the idle SA table right around idle, that should smooth out the idle by not making SA jump all around. Your SA is anywhere between 4 and 16 at idle and IAC steps are just as bad. Those two items should almost be rock steady.

I'm not sure exactly what the PW is? Pulse width as in number of miliseconds injector is on? During my last log, I thought I enabled data tracing so I could see precisely what cells I idle @ on the IDLE VE table. But, when reviewing the log there is no data tracing for some reason..... I'll have to try again to log with data tracing enabled and get back with an answer for EXACTLY what RPM/MAP cells the idle is. In the meantime I've tried flattening out the low RPM/MAP area on both VE tables for what I THINK is the general idle area on the VE tables. Also made the changes to spark advance, flattening out idle area as suggested.

The little bit of idle in beginning of log looks bad... most in open loop and RICH. Look at O2 data in .900 to .800 range = rich... First thing is temp at 100C is 212 F is high and could be adjusting for it in bin. Second is MAP, RPM and Spark are rocking back and forth so bad your entering AE, may need to raise idle some for cam, steady spark timing by leveling it out and even raise it some, lean out VE...

Ahh I bet you're right about the high temp... See what I did was set my Fan ON temp to 10 degrees ABOVE what my T-stat is, which is a 195F stocker. I did this because it was what 93V8S10 did with his own fan settings with that '427 E-fan code, only he used 165F T-stat..... In the thread I started about the E-fan code I asked about this and I remember RobertI said this was to potentially avoid increased thermal cycling...
Anywho: I lowered my Fan ON temp to right @ when the T-stat opens up (195F).

I raised the Idle SPeed tables by 100 RPM so that my target idle when up to operating temp should be around 625-650-ish RPM. Come to think of it, I think the idle speed tables for this bin (BJLH) w/ a automatic are just going to be low in general for a vehicle running this bin, but with a manual trans.. I remember when I was messing with my '7747 I used a manual based bin and compared the idle speed table in a manual bin to a bin from an automatic and found the manual to be roughly 100-150-ish RPM higher than a comparably equipped truck with an automatic.




I know I've been able to get data tracing to work in TP before, but I can't remember, do you have to link the XDF to ADX on the laptop used for datalogging?

[EagleMark]

Your working on all the right things to get the idle dialed in!

Data tracing:
http://www.gearhead-efi.com/Fuel-Inj...unerPro-How-To

[CDeeZ]

Okay that's good to hear. Thanks for the help and words of encouragement.

I read the thread on data tracing and have now successfully setup data tracing on both VE tables... Success! Just need to setup data tracing for spark, idle speed tables and a few other things ....

BTW, did one of the $42 XDF/ADX combos we have laying around here already have data tracing setup? Seems like I remember connecting with the old '7747 and just clicking the data tracing button in TP and BAM! it worked without any manually changing of XDF.

[EagleMark]

All of the $42 files I have been working on since V4 have Data Tracing set up. They have to be used as a set.

[CDeeZ]

Well that must explain it! I believe the first $42 file of your work I got was the V4 (both XDF and ADX)

[CDeeZ]

Mark, I have been going through setting up data tracing for my $0D XDF... So far I have data tracing enabled on BOTH VE tables, BOTH spark tables, and BOTH Idle Speed tables (there are actually 4 idle speed tables, but only the two for "DRIVE" apply to me since I'm manual trans)

Can you think of anything else I could benefit from setting up for data tracing?

[CDeeZ]

Well after making those changes it seems to idle worse. Cold started and the idle is still rough, and also oscillating between 600-1000RPM, sometimes dipping as low as 400 RPM. What do I do now?

[EagleMark]

Mark, I have been going through setting up data tracing for my $0D XDF... So far I have data tracing enabled on BOTH VE tables, BOTH spark tables, and BOTH Idle Speed tables (there are actually 4 idle speed tables, but only the two for "DRIVE" apply to me since I'm manual trans)

Can you think of anything else I could benefit from setting up for data tracing?

Not really, If you find you need something add it.

[CDeeZ]

I burned another chip this time with only the idle area flattened in the IDLE VE table, seems to be better but I'm not sure if that's just because the engine was up to operating temp by the time I was running that particular bin, or if that fixed it.

[EagleMark]

Always base your decisions on a warmed up engine with at least a rev up to 1500 RPM or so for at least 30 seconds. Then see where your at and adjust.

Should really only have to make changes to Idle tables as you have VSS so it knows when Idling and speed.

Do you have CCP? Cause it's coming on and off.

Do you have EGR because it has a Diagnostic Interupt reset on and your error code is off? Not sure what that would effect...

No TCC but it is checked and a TCC flag is coming on and off?

TCC Clutch only is checked?

Closed Loop Idle is not checked and supposed to be on manual trans from notes?

Why did you choose a Auto bin to start a Manual trans rig?

Initial Spark is 4.9 and should be 0?

Cylinder volume has been changed, not Small Block and not Big Block?

Injector Size is Big Block? I think you raised that to lean things out IIRC? But I think you should set up the calibration properly to start.

Varible Tuning Control is enabled in Bitmasks in ADX and I don't even know what that is?

All that said and I don't know if any of that is your issue as I had more issues with the kids truck and it idled smooth... but you had 7747 on this before so did it idle smooth?

[CDeeZ]

So are you saying I should paste in the stock VE tables and start over with trying to fix idle?


There is a charcoal canister under the hood yes, but is that different than CCP?


NO EGR, I got rid of that years ago............................


For the TCC :

400F bit 7: Manual Transmission, On = Manual Trans, Off = Auto Trans

400F bit 6: TCC Only (non electronic trans), On = Auto trans with TCC control only, Off = Auto trans with electronic shift and TCC control

Edit: 400F bit 6 and 400E bit 2 must be on if a manual trans is used.

Close loop idle was NEVER enabled on the bin I'm using BJLH so I just left that alone




I chose the auto bin b/c the only known manual bins for the 7427 are for either a V6 or big block, I tried the big block tune and it ran terrible as I expected it would. So I picked the auto bin b/c it was a 350 bin.............


Initial Spark advance is set to 4.9 degrees, because my distributor is set to 4.9 degrees base timing.......................


Cylinder volume has been changed because the engine is bored .060 over, thereby increasing the cylinder volume.


Injector size I just kept raising until it started to halfway idle decently, as per dave w's instructions.


Variable tuning control: your guess is as good as mine.


Yes I had the 7747 before and it did idle more smoothly. If you recall, I made an adapter for the 7427 PCM, so today I swapped the 7747 back in mere seconds and the idle is indeed smoother than the 7427 for whatever reason....


I'm all for setting up the calibration properly to start, which is what I tried to do. But if you think I can do better in some way please specifically tell me what I can try.

[EagleMark]

Well at least you have answers for all I saw!

But if it ran smooth with 7747 and now it does not then it has got to be a bin issue! Can't find any wiring issues, IAC is working like crazy trying to keep up, everything seems to be?

I think I found the issue? I compared the differences from your bin to the stock bin and found lots of changes that are fine. But about 50 that are undifined meaning something has changed that does not have a paremeter value in TunerPro XDF... = something bad happened...