I'm having a bit of trouble tuning regarding the 16168625 ecm using E_6. This ecm was used for 93 chevy p/u 4l60 and a few others maybe.

For example: There are two main fuel tables. Table one is described as "open" and table two as "closed". My interpretation is that table two is NOT an adder as like most?

There are also other numerous tables that appear to be "idle related" but it's not clear as which table is used for the actual idle term and when it's term are in effect.

If anyone is famular with this ecm, any help with it's table functions would be greatly appreciated.

 

Open means open throttle, there's usually a min TPD setting somewhere, to determine open and closed levels.

 

There is also a minimum VSS (MPH) term to enable "Open Throttle" fuel. Same goes for spark. For example: as long as the TPS is less than 3% AND the VSS is less than 3MPH, the closed throttle fuel table is used. HTH

 

The 'closed throttle' SA + fuel tables are for use when the engine is idling. Theres alot of stuff that the PCM does control wise to give a steady idle, so seperate tables are given for idle vs. driving.

There is also lots and lots of other stuff for the idle. What else did you have questions about?

 

I was speaking in general, as far as there being a min TPS.
BTW, I didn't say it was the only enable.
If one really wanted to get tech., we could agrue the symatics of *Open Throttle*, would be inclusive of all the enables for that flag to be set.

 

No flame intended towards you. Just trying to enlighten the original poster. Being an engineer, it takes a conscientious effort for me to not get technical. It's a bad habbit to have at times.

 

That was my interpretation also, so when calculating the overage or underage of fuel for idle, I am assuming that the "open" or table # 1 one is used exclusvely for this? At the moment I am only working on idle only. Both during open and closed loop.

There are also 3 other tables that seem very closely related to idle only which I'm not totally convinced I have understood so please correct me if my interpretations are wrong.

Startup AFR correction (choke) vs. coolant temp: Richens fuel based on coolant temp during open loop only? Richens Main fuel table # 1?

Open loop AFR vs. coolant vs. MAP:This would be the AFR the ecm is calling for during open loop with the above table adding fuel based on temp?

Crank BPW vs.Coolant temp: Would this be the pump shot during cranking only then once the ecm considers it to be running then transfers back to above table?

Are my interpretations of these tables somewhat close? I havent even dared mess with all the IAC and airflow tables yet, but I feel once I get an idea of what the table parameters are all about,this seems to be a pretty decent ecm to be able to tune where as there are so many function which many are so closely related.

 

There are several tables for when your cranking. Off the top of my head, theres one that has the base cranking PW, and others that have multipliers for how long youve been cranking.

The startup choke is only briefly active after startup and works in a similar fashion to a choke on a lawnmower, but its alot smoother.

The open loop AFR is used whenever your running in open loop.

See the very end of 'TBI Guys, its time to update!" on this board. It should still up near the top. I posted a hack with some more in depth info. It might not be the same mask, but itll be similar to whats in yours.