[paulm]

So anyone who is using or has used the C950 system have any tips, tricks or good issues and their solutions?


A couple of things that I ran across are:

** When using a cam gear driven computer controlled distributor, the timing will fluctuate a few degrees +/- at idle. Don't know why but I thought I had a major problem when I ran into this, but it turned that it's normal. This happens even if you disable idle spark control.

** Sometimes when making a change to the ECU settings, the "Modifiers" parameters can get set to their default and the default value for the "Additional Timing vs Coolant Temp" is -32. This will retard the timing by 32 degrees and obviously make then engine run like crap.

** Apparently when setting up the fuel map it is bad to set two adjacent cells in the same RPM to the same value. This will cause the idle to roam a bit. So always set adjacent cell values in the same RPM to differ by at least one.

** At idle the ECU uses the IAC to control the RPM. It can also use timing if idle spark control is enabled, but nothing else.

** You can have two output switches. The thing is that you have to wire them into the connector yourself. You don't get the proper connector in the kit, but if you call up Holley they will send you out a couple. Then you can add it into the plug (use the schematic to find the right spot to plug it into) and you're golden.

[paulm]

Ha!!! I found another interesting tidbit of knowledge! So, apparently the IAC motor is especially susceptible to electronic noise. This noise can cause the IAC to get a little wacky and open or close more or less than what the ECU is telling it to do causing a wacky idle. This noise could be produced by alternators, starters, etc.

There is a "fix" for this in firmware 3.6 and above. You need to set the "Minimum IAC Position" to zero under Hdwr Settings>>Idle Air Control for certain boxes. As an example if you are at idle and your TPS reads 30, you would set the box with the next higher number than 30 (as an example 32) to zero and all boxes to the left of that to zero.

[JimM]

That's the one I was trying to think of!

[Fred Ficarra]

Wonder if Mass Flo is shaking in their boots?