Hello:
1986 Corvette

My cold start injector system on my 86 has gone for crap.....

i will be diagnosing it at a later date, but would probably just like to block it off and re-tune my chip for extra fuel at start up.

I put in a generic arap $6e to test it and it fires up great.
My custom PCM4LESS $32 chip takes forever to catch without the CSI working properly while cranking...8+ secs. Starts and runs great when warmed up.

My question is, what do i have to change/add in my $32 bin to mirror the starting power of the ARAP $6E. I see $6e has more "fuel cranking" tables than $32

Right now in the $32 i am using the original values in the "crank fuel vs coolant temp" table

I would prefer to continue to use my $32 bin instead of starting over tuning the $6e

 

I would start with tables that affect the AFR/PW based on coolant temperature.

CRANK FUEL vs COOLANT Temp.
START UP ENRICH vs COOL

May need to lengthen the decay rate for the start up enrichment.

And possibly this one:

OPEN LOOP A/F % CHANGE VS COOL TEMP

RBob.

 

Thanks for chiming in on this RBob...i spend alot of time reading your posts.

I do not have all the tables in my 32 bin that you listed.

See attached photo for the closet tables i have to what you mentioned and the current values i am using in those tables.

Anything here to work with? I wouldn't dare want to start changing numbers without a bit of guidance...Thanks

 

After playing around with various fuel tables in my $32 bin....with not much luck, i have decided to stick with the ARAP $6e...seems to work flawlessly. Only had to make a few minor changes to the MAF tables to bring the BLM's to a respectful number.

The only major difference i see right away using this bin is that i dont have my high (choke) idle at cold start-up like the $32 bin....seems to fire up and settle AT The 1000 rpm range...no biggie..just different. The table, coolant temps vs rpm HAVE THE SAME VALUES IN BOTH BINS?

 

Using $6E is a good choice, it does have advantages over $32. Note that there is a lean cruise mode that can be used for better highway mileage.

As for the crank tables, there are more then what is listed in the ECU/XDF files. So likely one or more of the others are different.

RBob.

 

I would have tried crank pw vs coolant for cold starts in 32 but i have only worked with 6e and like it alot.

There is a few iac tables i believe for startup..Cold idle is always high at first and gradually tapers off as it warms but maybe you have too much airflow from large iac count?. You could play with those tables.

Other thing that could cause that is timing and arap has alot of advance which will force higher idle speed. May want to back it down some in the idle lv8 areas if its stock arap table. Could copy over your old 32 table.

Then check actual fueling at idle at cold start. Rich or lean can help get it to idle better.