Hey folks, I'd like some help. I have a mild built 350, mild flat tappet cam, stock swirl port heads, intake and throttle body. The injectors are 305 injectors. My dad set the timing to 18° (he refuses to turn it down so please don't ask.) Can you folks give me tips? I will be swapping to TPI soon but I want to have some oomph for the time being. It does get out of the hole with ease but after 2500rpm or 35mph, falls on its face or acts like it's misfiring.

Thanks!

 

Dad must be an old school carb & mechanical distributor guy. Set the distributor base timing, with the EST/BYPASS open, to 6° BTDC. Then set that same value in the calibration as this parameter:

SA - Initial SA

That way the ECM knows the base timing and will take it into account.

You are going to need more injector flow as 305 injectors are too small for a mild 350. Can either install larger injectors or turn up the fuel pressure. Can use the EBL Utility to get an idea of a fuel pressure and/or injector change.

Once that is done change the BPC vs VAC table to match.

Can then start off with VE Learns.

RBob.

 

Thanks Rob.

Since Dad is still being stubborn to listen to knowledgeable EFI folks, I have to tell the EBL to run 18 base but not go over 35 full throttle. As for the VE Learns, it will depend on the situation. I will probably have to adjust manually.

Charles DeCapua

 

Then show him, he is thinking that the 18° BTDC for base timing is where the engine is going to idle. It won't. The idle timing will be based on this parameter:

SA - Idle State SA

The base timing is only used during cranking. Once the engine is running the ECM controls the spark advance (SA).

You are likely to find that 35° BTDC at WOT is going to cause a lot of knock. Even a hot start is going to knock on 18° of SA.

If you want to try it, set the base to 18° BTDC and set this parameter to match:

SA - Initial SA

I can tell you now that this is going to get ugly, just way too much SA for a swirl port headed engine....

And whatever you do, do not change the Minimum and Maximum SA values in the BIN. With your engine they are defined by the physical constraints of the distributor. Nothing more, nothing less. These two (do not change):

SA - Maximum SA with Positive Value
SA - Minimum SA with Negative Value

RBob.