New member setting up a new system, 58 Buick.
Ok sounds good. We have about a month before the first road trip of about 250 miles so we’ll get to driving it. I have started removing some of the accel and made it more responsive if you roll in to it fairly slow steady but the fast is fighting me so I’ll hold off on that.
I’ll change the prime first thing, it’s at 259. These Buick’s load up on the oil pump very hard when fired cold but after that first start it’s getting somewhat better but I can tell where that’s very sensitive.
If we disable the DFCO is that temporary or are you saying we can leave it off and it will respond fine without?
How many miles would you like before I log again and how long until we log driving?
Thanks again!
DFCO can be disabled long term. No adverse affects. I shut mine off. It is only to minimize fuel consumption, but can create other issues. Such as stalling during hard braking events and being sluggish between gear changes on standards. Plus it may sound unpleasant to you.
If you drive some tomorrow, try another log. What you want to see is small AFR trims. This means the AFR Learn, or long term trim has stored a memory or learned what your engine wants at that particular load and RPM. When trims stay within +/-10% most of the time, you are getting a really good learn.
Another thing to look into is your Target AFR. I like to start with the Idle AFR first. Every build is different, so comparing numbers to Stoich or some other build will most likely not work. I start by adjusting the AFR while idleing, listening to the exhaust and watching the vacuum. The same way you would on a carb. Just no leaning over a running engine with a screwdriver. When you feel good about your Target AFR, pull the plugs and read them. You might want to adjust slightly. From there you can use your idle AFR target to build upon for the rest of your tune. Higher loads and RPM are going to be slightly richer. Fyi, when you adjust AFR, it will change the learn. So be patient and let it do its thing.
Ok, to eliminate confusion, I did the update which fixed the upside down screen. Thanks
Started over from scratch without me doing anything other than the prime shot to -100 which made it start worlds better and not bog even on the first hit, I turned off the DFCO, and then drove it to get fuel and put two miles on it to get to temp so that now we have a new baseline to start. I did set the IAC back to 15ish. Once the rain clears we will hit the road.
Thanks
https://www.dropbox.com/s/gkhqcdcdmufy39w/DashBoard1.csv?dl=0
We are considering setting the timing back a hair to 10ish. Looking for the vacuum gauge now so we can check and set it more accurate. Would retarding it help any that you are seeing?
Thanks
I have no idea. That is up to you. There is a vacuum gauge on the handheld....
True! I wasn’t thinking that simple.... 🤦🏻♂️
Had severe weather all day so no time to enjoy the car. We’ll play with timing tonight or tomorrow and hope to drive it!
Good afternoon! Got to put a good 120 plus miles on it this weekend. I found you thread with the AFR suggestions and it seems this car like lean. I set the AFR's in all tables to the leanest side of your suggestions. Runs good but seems to drink the fuel. When changing the AFR, how many tenths do you suggest I move between drives and testing?
Attached are two tables. One idle and one with the cruise set at 70. Thanks again!
https://www.dropbox.com/s/g7lzdm5ta327tk9/DashBoard4.csv?dl=0
https://www.dropbox.com/s/vvoix939qb2vdpa/DashBoard3.csv?dl=0
Datalog is looking really good. Your second one didn't come through. No worries.
Get your idle AFR line out the same as you would adjust idle mixture screws. Vacuum, exhaust note, plugs. After that, use that AFR number to help build the rest of your targets. Depending on the use and build, your best results will vary from others. I tend to move a half point at a time.
I see that it put the second log with the first one. When it went to idle speeds would have been the second one. We will check a plug next.
Thanks
In the relation of cylinder temp to coolant temp. At what separation does it consider too lean or fat? I noticed at 201 coolant we had 161 cylinder which seems pretty cool.