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 (http://forum.efilive.com/showthread.php?t=4661)
showthread.php?t=7866 (http://forum.efilive.com/showthread.php?t=7866)
showthread.php?t=7867 (http://forum.efilive.com/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 (http://forum.efilive.com/member.php?u=10)

[joecar]

Fuelmass can be calculated from commanded AFR if the airmass is known... the airmass comes from either of the VE or MAF.

[L31Sleeper]

OOOOOOOOOOOOOOOOOOOoooooooooooooooooooo........... ....BRILLIANT !!!

[L31Sleeper]

So the commanded fuel table by it self if you had feed back from a
WBO2

[joecar]

So the commanded fuel table by it self if you had feed back from a WBO2No...

You use the wideband feedback to correct the VE table...

You set the commanded AFR to values known to provide desired performance... (since your VE is corrected, the wideband measured AFR will equal the commanded AFR)...

e.g.:
low load and idle: 14.7
high load and WOT: 12.6

i.e.
to the left of column 80kPa is like 14.7 or 14.6,
to the right to column 80kPa is 12.6.

[...the commanded AFR table operates during open loop (i.e. at WOT or if you disabled closed loop)...]

You correct the VE table; you set the commanded AFR table...

[...when the IFR and VE tables are correct, then various other "things" all fall into line...]

The objective is to get the wideband AFR to equal the commanded AFR at all times... in OLSD (open loop, MAF-less) the VE table is the key to this.


If you go drag racing, you first beforehand correct your VE table using the wideband... after doing this your wideband AFR will equal your commanded AFR... then for each run you edit the commanded AFR slightly and see if your ET improves or not, you keep doing this until you achieve the fastest ET...

On the dyno, the VE is first corrected (using wideband)... and then the commanded AFR is adjusted until best power/torque is seen...

The AFR range 12.6-12.8-13.0 has been well known by many drag racers for many years (30-40), it has been arrived at experimentally/empirically to obtain best ET's or best TS.

:)

[joecar]

Follow the four steps:


...
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;...

[joecar]

For example (say we're in OLSD -- open loop, no MAF)...

The PCM reads the VE table and calculates (lets say) 2.0 grams of air to be the cylinder airfill...

PCM then looks up the AFR to command, lets say the commanded AFR table says 10:1 (for easy numbers)...

From those two numbers, the PCM calculates it needs 0.2 grams of fuel (i.e. divide 2.0 g by 10)...

i.e. the ratio 2.0g air to 0.2g fuel is 10:1.


[of course, 10:1 is extremely rich, you wouldn't normally run that].

[joecar]

Then after calculating it needs 0.2 grams fuel, the PCM looks up the injector flowrate table to see how much the injector flows...

let say the injector flows 2 grams/second... to deliver 0.2 grams the injector would have to be opened for 0.1 second (i.e. divide 0.2 g/s by 2)...

so by firing the injector for 0.1 second will, after combustion (assuming no misfire) cause the wideband to measured the AFR to be 10:1 assuming the VE table is correct.

[I don't know of any injectors having a flowrate as low as 2 g/s... I used this for the example calculation only]...

[and an injector on time of 0.1 s would exceed the available time (i.e. 2 crank revolutions) and so would exceed 100% injector duty cycle].

:)

[L31Sleeper]

Sorry if that last comment confused you guys.......I was talking about
other stand alone systems that use Commanded AFR in place of VE
with feed back from a WBO2 to make sure it is geting that AFR.

[joecar]

Oh... sorry... misread... :doh2:

Yes, the wideband in closed loop feedback... some standalones use this and some OEM's like VW.

Other standalones use narrowband feedback just like GM.

[L31Sleeper]

Thank you everyone for your help. It's running good now. The only thing
that seems strange to me is that my timing hasn't changed but spark table
PID is showing 200% I thought 0% was the Low Octane table and 100% was
the High Octane table ??

[5.7ute]

Strange, can you post a log file of this?

[L31Sleeper]

Sorry it took sooo long I switched from COS3 to COS5 the truck still runs good
but the problem persists, also I realized that it IS affecting my total timing.

so here is the file. The PID : ASPARK is 163% ??