Ferrari 308 with EFI...Need help with Fuel map

Don't know if there is a forum for the Holley 950 Commander but try some of the EFI forums that support programs such as EFILive, etc. Lot of people doing reprogramming of LS engines and the principles should be the same.

 

You might try www.chevytalk.org. Look under their special forums heading for EFI/Fuel Injection & Engine Management Systems. It is my understanding that an engineer from Holley hangs out there and might be a help. It is also my understanding that the Commander 950 requires you to know how to tune the fuel maps. You might also look for a Holley EFI dealer in your area. They might be able to hook you up with a tuner. If you were in Northern California, I could set you up with a couple of tuners for the fuel maps.
Good Luck!

 

I can't answer the question, but I'd love to see a picture of the setup.

 

If you have not figured everything out, perhaps I can help. I am not familiar with the Holley setup, but I am very familiar with the Electromotive TEC3. If you can give me some parameters, I can work up a map for the Volumetic Efficiency Table. Also I will need to know your Advance table.

Variables:

Injector size
Fuel pressure
Max Controllable PulseWidth (TOG)
User Adjustable PulseWidth (UAP)
Pulsewidth Offset Time (POT)
Minimum Injector turn-on time (MIT)

 

I doubt you'll find a ready made VE table for your 308.

I installed a MegaSquirt on my 400i and the only way I've been able to tune it is by using a wide band O2 and LOTS of data logging.

You've actually got past the hardest part. If the engine starts and idles, you're 90% there.

Does your fuel regulator have vacuum (load) compensation?
Are you in the ball park with the injector flow rate?
Did you test the injector flow rates?
Are all of the injector flow rates nearly matched?

It doesn't really matter if the overall flow rate is a little off. It will simply offset the VE table. As long as you don't "bottom out", you'll be OK.


So as you said, get a wide band O2 sensor in the exhaust.
I just did a quick read of the manual for the Holley 950 and it looks like the closed loop operation has a +- 10% range but it needs to start somewhere.

Unfortunately, the unit doesn't seem to have an auto-tune feature. This means you'll have to have someone drive you around while you monitor the AFR and adjust the VE. Maybe you can find someone that has a dyno so you can do it yourself.

As you go through this process there are a few things to keep in mind.
1. If the engine starts to misfire, you get MAJOR errors from the O2 sensor. The O2 will see the oxygen in the exhaust and think the fuel is lean. The 950 will add more fuel making the misfire worse...
2. The O2 sensor and the 950 are very fast. You should adjust the delay/averaging of the O2 readings to get smoothed results. It's hard to make adjustments when the AFR reading is bouncing all over the place. The delay is the time to wait for the puff of exhaust from the most recent event to reach the O2 sensor. The averaging helps to see past the occasional misfire.
3. You may want to start with the target AFR set to 14.5 of so and adjust the VE so that you mostly hit the target AFR. This will allow you to setup a true VE map of the engine. Once the VE is correct, you simple enter the desired AFR table.
4. Work on one effort at a time. Get the engine warmed up on a warm day and make sure all temp and other compensations are off. Then make small changes, saving your tune files often so you can go back to a known good state.
5. O2 sensors aren't perfect. Wide band sensors are often bad right out of the box. If your tuning efforts seem to be making things worse, it might be a bad sensor.
6. Make sure your other sensors are working well. I've seen a loose wire on a temperature sensor intermittently stall an engine because the ECU would see the hot engine as dead cold and suddenly crank up the AFR. Log everything and review it until you are positive they all work.

Well, good luck.
If you PM me I'll give my cell phone number. I hope I can help.

 

Perhaps others will way in, but when I was doing my setup, I had the O2 sensor disconnected. I then created the VE table. This I did while on the dyno. Then, I connected the O2 sensor to smooth out some of the transitions and to take into account changing conditions. BTW, this is for a 308 QV. On a side note, I have read confliction opinions a wide band O2 sensor and their ability to "keep up" with engine changes. I am using a standard O2 sensor. Also, I must say I was fortunate in that the people at Electromotive were extremely helpful during whole process.