EFI conversion, where to find the perfect fuel map

The EFI conversion of my 308 is working but running rough. The prototype phase has been mostly a success, and also finally got rid of all that smoke ! It took a long time to burn off all the oil in the exhaust sys. but it finally stopped smoking. Oil smoke is now 95% reduced from starting point 2 weeks ago.

Fuel Maps: When I had this EFI system on my Ford 390, I had to try so many fuel maps to make it work, but this Ferrari engine is very different from a BB Ford, and so I am starting from scratch trying to find and tweak the best fuel map.

BTW, am I dreaming, or is it ever possible to get a CIS to EFI conversion to pass a smog test in Calif ?

Any suggestions on where to get some appropriate fuel maps, and how to tune the EFI to work on the Ferrari 308 would be greatly appreciated.

Also, here's a photo of the nearly finished EFI in the breadboard state.

Andy
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Do a search for Dan Fodge. I thought I had his shop number in my cell phone. I just had lunch with him a month or so ago... I'll find it tomorrow or call the house. His email is [email protected]

I know its cliche, but Dan "wrote the book" on EFI - Literally. He built some of the first Indy car FI units and is still building custom FI systems today. If he can't help you... it can't be done.

Rick

 

Andy,
There are not millions of maps out there to be had for 308 efi conversion....you normally have to write your own.

What brand injection system are you using and what size injectors as bother will effect what the fuel mpa looks like.

What did you do for an ignition map?

The way most people start is to go to the ferrari service manual and have a look at the CIS ingnition map graphs then do you best to recreate them in your ignition map and you will be really close ignion wise.

For fuel I need to know what the ecu is asking....injection time of VE are the more common? Once I know that we can go from there.

BTW, you don't want it mounted low with the inlet point up btw, it can collect water

 

The EFI system is a Holley Commander 950, the ignition is the original Marelli ignition system, still connected and working. The injectors are 8x Denso 24 lb. (taken off a Lincoln town car 4.6 V8)

I may install a TFI ignition system eventually, but for now the Marelli ignition is working OK.

 

OK, what units are on the numbers that control fuel? time? VE? If its time I just finish doing a 2v cis conversion using ford 24lb injectors. The injection time at idle is about 1.6ms, about 4.6ms full power....these are semisequentail, for full seq I would guess about 2.2 idle and about 8.2 full power and pretty liniear in between. I hope that helps

 

The fuel map uses units that I can't quite identify, perhaps they are just arbitrary numbers that are intended to be relative to each other only, the numbers that tell the real story are the pulse width and duty cycle numbers that are read out realtime on the computer while running. I recall they looked about right, pulse width was about 6 ms at idle, and duty cycle was pretty low, less than 10.

I will look in the Holley manual and see how they define the values in the fuel map. Also, when I first started it, the MAP sensor reading was so low (about 10" vacuum) that I switched to alpha for a while, that did work, but not really any better.

I see from the Mondial WSM that the vacuum of the 308 k-jet engine at idle should be about 10" Hg, so that's about right.

I switched back to speed density, and the map sensor, while it is operating in the lower half of it's range, it is working. That gives me a lot fewer fuel map cells to work with.

I will go run it some more today and answer your questions.

Andy