Hammered

This is my first post hear so please excuse me if I'm breaking edicate by posting a non-3rdgen question. The car is a Firebird though and this is by far the most informative board I've come accross with respect to EFI info.

I'm converting a traditional Pontiac over to EFI and am nearly ready for the engine dyno. I've got the Accel DFI Gen 7, V3.6 ECM with WBO2. I've read Jeff Hartman's Engine Management Systems book as well as a couple of others along with devouring every board with relevant info. Still, I want to hear from some seasoned experts.

Assuming I get everything setup correctly and the engine started, I would like to know if I'm correct in my approach:

1. Step through the RPM range at full load or WOT, setting the VE table so that a small correction from rich to lean is made by the ECM.

2. Step through the RPM range again at WOT, setting the timing for max power, being careful to stay a few degrees away from knocking.

3. Step through a third time at WOT and adjust the Air/Fuel ratio table for maximum power.

4. Step through a forth time at partial load and adjust the VE table only?

5. Perform the rest of the tuning on the street?

Also, I understand that there is an EMIC manual. Is it possible to get one of these?

Thanks in advance,

John

aDFIguy

You have it pretty well right. Once you see an actual A/F ratio that matches your targeted value, you shouldn't have to touch the VE table anymore. When doing part throttle/acceleration, your first pass can be on the VE table. After that, favor the acceleration fuel tables over the VE table.

I think the EMIC manual is floating around on the 'net if you look hard enough. However, it is geared toward the older gen 6 stuff, and hasn't been updated for the gen 7.

Hammered

aDFIguy,

Thanks, I'm glad to know I'm thinkin' the right way. When you refer to the acceleration table, I presume you're talking about the tau/X Vs. MAP and ECT table? It's my understanding that this only affects the asynchronous fueling under acceleration and not steady-state conditions.

John

aDFIguy

That's right, Tau vs. MAP/RPM is the main transient fueling table used to control accel/decel fueling. However, since the system is MAP based, you need to set all the transient fuel tables properly to make sure that they only are invoked when you want them.

For example, say you have an aggressive cam that causes transient changes in MAP while idling. If your acceleration threshold table set too sensitive, the ECM could pick up on the MAP fluctuations and give you acceleration fuel when you don't need it. This can make idle tuning a pain if you don't catch on to what is happening.

Hammered

Thanks again, your explanation makes that more clear also.

John