However my stock RamJet 350 is still not idling smoothly. I guess it's time to start adjusting timing.
I'm not clear at all on the timing aspect. As I superficially understand it, I have set the engine timing to the timing value in the BIN ...6 degrees in this case.
Any hints on what it is that I need to adjust....would it be the "SPARK ADVANCE MAIN" table?

 

As a starter, I'll refer you to an LT1 spark table, from what I gather, that's what it suggested for Vortecs. That's what I have in there now, seems to run OK, I'm working on other issues at the moment, so I'm not making any adjustments to the table so I can't even tell you where to begin on that.

However, I put my idle SA vs. RPM table to align with my main SA table, where it idles of course, in terms of MAP.

I couldn't get mine to idle nice at all, don't know if it's the cam or what, even though fueling is very close, verified by blms and wideband. In order to get it to idle nicely, by trial and error, I found that tweaking the SA vs. RPM error tables helped tremendously, and it was actually in contrast to what I read that normally helps...that is, lowering the values.

Here are my tables, maybe they will help you out:

 

And one more:

 

I'll save a new BIN and keep the old one because it seems as if most of the BLMs are good at upper RPM...only a couple of oddball ones that I figured I could address after I got this thing to idle.

On a side note, I was emulating yesterday, and when I burned a chip it didn't run the same....so I did it again....still weird. I swapped chips and then it worked...amazing! I actually think I have a bad chip.

I'll try these new values and report back.

 

While I certainly am not an expert I just went through getting a smoothed out idle on a new install. I don't know what ECM you are using but I am using a 730. From what I read in the archives and have been given advice on in some posts is: First with the engine warmed up disconnect the timing connector so you are at your base timing. Lets say that's 10 BTDC. Advance the dist until you get the highest vaccuum at idle. It helps to have a dial type timing light (I didn't so I guessed about where I was). Then put the dist back to 10 BTDC. Now go to the main spark table and enter the timing advance that gave you the best vaccuum. Let's say that's 25 BTDC. So you adjust your main spark table and the closed throttle table. Also in the main spark table it helps to level the surrounding cells to help smooth the idle. Also I reduced the amount of retard and advance the ECM can do for error. All this helps reduce the hopping around the ECM can do at idle to help make things smoother. Also in my application I had an issue with a cold start/open loop below 90 degrees. So I made sure that the 100kpa column in the RPM range I idled at matched what I wanted my closed loop idle spark to be. I burned this in the eprom and reset the ECM. Then let the car get to temp shut it off and did the Min. Air adjust on the IAC to be 50 less then my target idle. Once I was done with that the car now idles at about an 8 out of 10. I haven't adjusted the O2 constants yet but that's next.

P.S. After going through all this just to be certain I had the best timing I changed my base timing 4 degrees advance and retarded (at the Dist) from 10* BTDC, reset the ECM and let the car idle in closed loop for several minutes. So if you dial in 25* in the eprom with a 10* base. I tried 8*, 6*, 12*, 14* at the dist. so my total went 23, 21, 27, 29. Hope this isn't too confusing.

 

My tunerprort appears to use slightly different names. I did make one change, I made the lower row of the upper rpm range match the upper row of the lower rpm range in the SPARK ADVANCE VS RPM VS MAP tables. I'll go try this and see what happens! Thanks.

 

Well, I spent the day playing with my idle. I am using a 730 ECM to run a Stock RamJet 350. I user TunerProRT for monitoring, emulating, and chip burning.

I entered all the info that I got from 5.7Ramjet into my BIN. I have the best idle that I've been able to get so far. It is still not a smooth idle, but it's as good as it's gotten. I had to adjust my timing (at distributor) to 12 degrees...I thought to be a bit odd, but ok. Generally my BLMs are workable until I get around to fine tuning.

I did encounter a problem that I had not seen before; when I go to accelerate, my BLMs go lean before they catch back up ....this concerns me because I don't want to have "lean" problems. Would it be caused by one of the 5 tables I edited from the above?

While I was this, I went ahead and disconnected the 730 and hooked up my MEFI-3.....just to see if it ran different. It does, it's quite a bit smoother with the MEFI, but it sure does stink...really rich, reminds of why I undertook this assignment. Needless to say, there must something else to tweak.

I'm leaving as is for now...I want to follow up on 84KYSS's post....that may let smooth the rest of this thing out. So, anyone have any info on why the BLMs go lean when I accelerate? They come back to "normalish", but I'd like to get rid of that lean problem. Thanks y'all.

 

If you re-set the dist, did you also correct that in the bin ?
That's important, else you have a whole lot of compensating to do.
I had that going lean thing, too.
My main VE fuel map WAS lean at high MAP.
Didn't get confused by AE, just stayed with what I knew.
AE is VERY short term. VE is constant. PE is based off of VE, so get the VE right first.
Stay below PE, or temporarily raise the threshhold, and get VE right.
BE CAREFUL disableing PE. You can hurt the motor if you're not sure of what you're doing here.

 

(or distributor setting), as it's called in my tunerprort thing. If it is set 6 degrees advanced in the BIN and I set the distributor at 12; what is it that I've done?

 

Effectively set it +6 degrees advanced across the board (at every point).

 

......and then just use an absolute value for the distributor adjustment?

 

Because there are reasons beyond human for these numbers.

Remember, you are programming a computer !
The computer doesn't know, or care, what the crank angle really is when it generates a spark.
It DOES know, and it DOES care, when it generates a spark command relative to the reference pulse coming in !! That means that yes, you can do as you propose. Simply set it at some arbitrary point, before or after top center, and remember this offset for all of the timing tables you will be working with, spark bias settings, when they apply, etc.
HOWEVER.....
Most of us, at one time or another, have experienced "limp mode" in the process of tuning.
What happens at that time, is that the computer becomes irrelevant. The static dist timing becomes EVERYTHING.
Below a certain RPM ( more correctly frequency of dist or crank trigger pulse ) the spark module, NOT the computer, generates a spark on the trailing edge of the reference pulse.
This occurs every time you crank the motor, before the computer sees any RPM from the incoming pulses at all. This is the crank/start spark timing.
When the computer sees the RPM above a certain number, usually 400 RPM, it then begins commanding spark based on all of its tables and maps, and the spark timing changes to what the computer is commanding, relative to the reference pulse.
In limp mode, the computer commands nothing, so the module alone sparks relative to that pulse, as above, below some RPM on the trailing edge. When that pulse goes above a frequency hard built into the module ( not the computer ) the module ( not the computer ) advances the spark a fixed number of milliseconds, or degrees, and it stays there until RPM drops below that threshold. Probably based on the time difference between the leading edge and the trailing edge, but I'm not certain.
This is all so you can "limp" home and get things fixed correctly.
If you set the reference too late, as I did, you may find, as I did, several hundred dollars later how this can affect your catalytic converter. You may find, as I did, that your exhaust flows freely enough to blow chunks of what used to be the converter right out the tailpipe !
Bad plan !!
If you set it too advanced, you may find that when the module advances relative to RPM that you go into severe detonation, and nothing will stop it except slowing down. On the freeway, in traffic, another bad plan.
Limp mode is to get you home, NOT for day to day driving.
The computer has a term to compensate, or to know, what the static limp mode timing is.
THAT is the static dist setting in the bin.
What the computer does with this number, is to *after* calculating all of the tables, bias, advance, retard, EGR, etc. is to come up with an advance number RELATIVE TO THE INCOMING PULSE, NOT the true crank angle. Then it applies the static timing. It subtracts out the static number so that the crank angle calculated is actually the real crank angle, and commands a spark.
If your static setting is correct, then you can manually calculate, adding EGR advance, subtracting knock retard, etc. and a timing light will show that number at the crank.
Since you are programming a computer, this is far easier if you're not lieing to the computer with a mechanical offset the computer doesn't know about.
SO............

In summary, there are three good reasons to do it right.
1. Limp mode, since this one can and will destroy parts.
2. Human, so that you don't have to think so hard about errors you have deliberately created, and compensate for them with other errors.
You'll have enough acidental errors so that ading more deliberately, will hurt you in the not so long run.
3. Distributor phasing. So that when a spark is commanded, the rotor is actually pointed at the correct pin for the correct cylinder. This is mechanicly built into the distributor, and you can't change it without a machine shop to remanufactur the dist.

Does this help ?

Aftethought. It may seem easier to add 6 degrees by simply turning the dist, but the right way is to add it all across the main spark map. The result is the same, and you won't regret it ( or have to remember it ) later.

 

and, IF I am understanding correctly, then what I should do is add 6 degrees throughout the MAIN SPARK ADVANCE and EXTENDED tables....that is, if I desire to maintain this setting? And then, set the distributor at 6 degrees?

 

You're catching on !
That's what I would do.

 

actually mean? Isn't the throttle actually always at least a little bit cracked open?

 

It's Idle Mode Spark Advance. There are parameters that define when in Idle Mode, changeable in TunerPro (I think it's speed < 18mph and TPS < 2.8%, off the top of my head, but something like that). You want these values to be close to your idle range values in the main SA table.

 

Am I somewhat understanding this? It would only come into effect if vehicle speed is "slow enough", and the throttle is released?

 

Basically, yes.

edit: If you're using TunerPro, there should be a bit that will tell you if you are in idle mode or not. I believe it is already in the .ads definition file that comes with the newest release of TP_RT. It's in the flags section of course. If you don't see it, I'll look and see what it is for you.