COS3 Idle no run ??

[L31Sleeper]

I have tried two different COS3s and I'm getting a rough idle and any throttle
tip in kills the engine? I started out with OS 12212156 (COS 02020003) later
I tried OS 12208322 (COS 01270003) same situation. I have a 1998 c1500
5.7L vortec with a 411 PCM.

[joecar]

What state is your tune in...?
Are the IFR/VE/MAF tables correct...?
What about the OL fuel table...?
Is the mechanical hardware working correctly...?

More info:
showthread.php?t=4661
showthread.php?t=7866
showthread.php?t=7867

Post tune file and log files.

[L31Sleeper]

Well I haven't had a chance to read those threads yet. But to answer those
questions, a full flash of the factory OS runs perfect either one. I don't think
it's a tuning issue some how I believe it's a OS issue.

[L31Sleeper]

Here is the OS 12208322 file that runs the truck perfect (like a bat out of hell)
and the COS3 that won't run worth a..........

[5.7ute]

Have a look at the tables under the Efilive custom calibrations tab. A0014 & A0008 need to be set to 1.0.
A0001,A0002 & A0011 need to be put back into range. To do this change A0001,A0002 to a value lower than 100, say 99. Change A0011 to two step. Save, close & reopen the file, then change them back & save again.
B3647 is also now wrong as it uses map v RPM instead of map v ECT like B3605 which it replaces. Change the low load areas to stoich & build up the enrichment as you want it in the higher map areas.
From then on you should be fine.
Note when commanding stoich the PCM will use STFT. If you are doing autoVe you will need to command away from stoich to prevent this from occuring. I use 14.5 to 1 AFR.
Something like this.(not for Autove)

[L31Sleeper]

Well that info was definitely help full I just don't understand why that change
was made from B3647 to B3605 ??

Why have a VE table if you have a commanded fuel table ??

[5.7ute]

Well that info was definitely help full I just don't understand why that change
was made from B3647 to B3605 ??

Why have a VE table if you have a commanded fuel table ??

VE & commanded fuel are not the same animal. VE is an airmass estimation table.
In a standard OS you had only ECT v MAP control over your AFR until PE kicked in which then gave you some control of fuelling v RPM.
B3647 gives you total control over all MAP & RPM points, with A0008 giving you the facility to enrichen according to ECT.
This then allows the PE function to be used solely for boost if more enrichment is required.

[L31Sleeper]

So how do the VE and commanded fuel tables not fight each other ??

If you are commanding 12:1 AFR and your VE table is set to give you 15:1 what happens??

[joecar]

Also set A0012, A0013 to in-range values.

[joecar]

So how do the VE and commanded fuel tables not fight each other ??

If you are commanding 12:1 AFR and your VE table is set to give you 15:1 what happens??

The VE table can't be set to AFR 15:1... it can be set to (for example) 1.5 g*K/kPa or 0.5 g @ 300K & 100kPa.


The PCM's basic calculation sequence goes something like this:
1. calculate the cylinder airmass (from B0101 VE or B5001 MAF);
2. lookup the commanded AFR (from B3601 in CL, or B3605 or B3647(COS) in OL;
3. calculate the fuelmass needed to deliver that AFR (using 1. and 2. above);
4. lookup the injector flowrate (from B4001) needed to deliver that fuelmass;
(along the way, the various modifier/correction tables are applied).

So the VE and OL Fuel tables do not fight each other.

More info (scroll down to September 24th, 2009), this expands on what 5.7ute said above: member.php?u=10