Discussion in 'The Injection Section' started by 1-ton, Jun 2, 2019.
No headers or anything that should cause excessive knock counts that I know of.
I was thinking of buying one of the Moats APU1 when I had the extra money laying around, but with the problems you are having with it you are talking me out of buying one. My truck is a lifted truck with aggressive off road tires that does not drive like a Cadillac.
I'm not going to lie, I'm hard on my stuff. My Autoprom is many years old...I got an earlier Autoprom from Mark Mansur back in the day, and that one didn't work properly either (he gave it to me with that discolosure) but I want to say it will allow you to at least datalog. Some of the issues I have may be self inflicted. I can't attribute the issues to how the truck rides, but I've noticed that the chip connections seem to be flakey. Sometimes re-inserting is necessary to get the chip to read and/or burn properly. Not to mention, the cables all over the place lead to the unit getting inadvertently jerked around when something drags across them, etc. And having the ECM hanging by it's wiring to hook the Autoprom serial cable up isn't my favorite either.
If you are stuck with the hardware solution due to the PCM, not sure what your other options are. But if someone has a way to control the trans and still be software-based, I'd probably go that route. Moates is a great company, always supportive of customers and the community, I just know the hardware stuff isn't as good for me as software would be.
I have fun doing the tuning, certainly better than burning chips over and over again to try and get things right.
The thing about Moats APU1 device is that you can use it to get the tune exactly right through emulation, and then use the same device to burn that tune on to a chip one time with no guessing or experimenting.
Oh it's great, but the problem is that there is no way you can tune a chip in one setting. Hot restart when it's 90* outside vs. 30*. Towing a trailer or empty. Climbing hills or flat ground. Cold starts. And to get it just right? That's months of tuning for me. And that is using "just right" loosely. I could still have better acceleration and open loop operation.
Part of it is that I don't have enough time to do much of the tuning at once. And I generally can't take long drives JUST to tune, it's always in conjunction with another reason to drive. But those are my problems.
Same issue for me. It’s just easier to make a tweak and program a chip again. Can take it for another drive the next day or two and take notes.
Did another data logging session after some more adjustments. I turned the fuel pressure down to 12-PSI. The BLM count got a little better. It looks like it is rich under acceleration, until I get up to cruising speed, and then it evens out with somewhat better BLM numbers. This will probably be the last data logging I do because there is not much more I can do with fuel pressure and timing to make anything better.
I reset the timing to 0-degrees advance, and that cut my knock count numbers almost in half from the previous data logging session when the time was set at 3-degrees advance. I was running regular gas during this data log session, and if I ran mid-grade gas I could cut the knock counts a couple of more numbers to an acceptable range.
Make sure to judge the BLM by “average” not the recent sample. Rich on acceleration is ok, that’s how it accelerates. I’d pull the fuel pressure down a bit more unless the BLM average is different than your pic. Maybe shoot for ~115.
BLM Average and Recent Sample look like they show mostly the same thing. BLM Average shows the numbers down to the 100th column, and Recent Sample just seems to round it off to the nearest whole number from what I can see.
The recent sample is the just most recent sample. If you hammer down the pedal, recent samples may show rich temporarily. Or other times it may be lean. The average is where your engine stays most of the time so that’s where you should be tuning for. Be careful, the difference is way more than rounded numbers!
I would not recommend changing timing by adjusting the distributor to advance it. The ECM is programmed to reference 0* when the motor is started. It will advance timing and "listen" for a ping as a reference (that is why the data log will always show 2 - 3 knocks at start up).
Set your distributor at 0* per the factory procedure (unplug brown wire etc) and leave it. Changes to timing should be made by programming the spark tables.
When I advanced the initial timing to 3 to 4 degrees advance that must be added to the programmed timing that my ECM has at lower RPM range because I definitely noticed a little more acceleration power from a dead stop. After I brought it back down to 0-degrees I lost a little of that power from the lower RPM range, but it is better to have lost a small gain in power on the lower RPM range then to have too many knock counts that are not good for the engine at the higher RPM range. Besides, what little I power gain by advancing the initial timing on the bottom of the RPM range the ECM will just take that power (i.e. timing advance) away on the upper RPM range when the knock count gets too high.
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