FAST ign. timing and CTS sensor

[70L34]

Hey everyone,

I have posted a few times on Chevytalk, but this forum seems packed with tons of great info. So here I am.
I have a Pontiac 468 with the FAST efi system. Recently got it running and I've been playing with the basics thus far.
The timing map is something I think I've done wrong. The default map in the ECU seemed to have a whole lot of initial timing at/off idle (34 if I remember right). I redid the table, trying to simulate a distributor with vacuum and mechanical advance. Basically the equivalent of 18 deg. initial, 38 total, with a 7 degree vacuum advance pod. Is this totally ridiculous? Am I still in the stone age?
I haven't been able to enter closed loop, either. Searched some posts and learned about the afterstart enrichment impeding closed loop, so I checked the table and saw it was ramping up enrichment from about 180 degrees on. I flattened it back to 0.4% but realized that the car probably hadn't been that hot tonight. And remembered a 15-20 degree discrepancy between my mechanical temp gauge and the electronic CTS parameter (CTS was reading 200+ all night). The CTS is in the intake, and the mechanical gauge is ported to the cylinder head. Is my CTS bad?

Thanks for the help!

 

[Craig Smith]

There's probably nothing wrong with the CTS. I've heard a lot that mechanical gauges seem to disagree with our CTS reading. Maybe we need to take another look at it...

After start fueling should also decay out after the car is started. Watch the screen when you start the car. You will see a sensor in the dash called ATS correction. If there is anything there besides a zero, closed loop won't work. You should see this number slowly approach zero. Other than that, make sure the closed loop enable check box is checked, verify the minimum temp you have for closed loop to work, and be certain that the closed loop high and low RPM settings are appropriately configured. Look in the manual on www.fuelairspark.com for a detailed explanation of how to get all this set up.

 

[TurboTR]

IMO you are doing the right thing with the timing. Just like an old distributor advance curve basically, then roll it off with increasing boost (if blown).

TurboTR