I've recently made the switch to the MS3 PNP in my 04 Cobra. It's a pretty basic set up as far as a Whipple and return fuel system. My first question lies in the return fuel system. I currently still have the FPDM in place as I was using it to give the stock type prime before start up as opposed to having the pumps run full time whenever the key is on. Looking through the MS3 manual I'm thinking I'm going to have to redo the pump wiring so they're on full time. Unless I can set the fuel pump mode to Open Loop PWM and set the values to 100%. I'm running the Walbro 450's so I can't run them as PWM. Plus I have them connected to relays so they get full power as soon as the relay is energized.
As I typed that I'm wondering if I answered my second question. I tried to drive the car today and it was pretty bad. As soon as I tried to accelerate I could watch the widebands jump from lean to rich. At first I thought it was an acceleration enrichment issue, but now I'm wondering if the Fuel Pump Mode had something to do with it.
I'm sure I will be here with many more questions in the future.
Correct. I used the output from the FPDM to trigger two relays. One for each pump. It required changing the voltage table to 15 in all of the boxes. And a couple other changes I don't remember off the top of my head.
I just started, but after watching a couple of your videos I think I'm going to start over with the idle and such. The real issue was when I would accelerate is when it would act up. When the throttle was steady state it would stabilize, albeit a little rich.
So it looks like I botched the idle set up. I swept through the ranges with the timing and the PWM duty cycle. After I made what I thought were the proper changes the car idled horribly. It wouldn't idle above 700rpm and I have my idle set to 800rpm. In between this I ended up bypassing the FPDM and now have the pumps running full time. I found that I needed to change the ground for the relay.
So I went back to the tune and it was just acting weird. The AFR between the banks was way off. Close to 2 points. And the timing wasn't changing at all. I triple checked that I put it back to using the table. I went back a couple restore points before I started trying to set the idle and it got a lot better. I haven't been using the idle setting going of some advice I was given. It's been ok, but I've been trying to make it better.
I attached the last couple of tunes I used and a steady state idle datalog just to see if I'm on the right track.
Give me some time to take a look, if I dont respond by tomorrow tag me in a post to remind me.
The way I do the settings is very straightforward for ms2, on ms3 the setup is slightly different. Do you have a copy of the tune with the changes made?
Ok so it looks like we have a small issue with the settings, not that you didnt understand the concept but more how to input them into the tables. I see the issue is you are trying to work out a small idle surge as the engine comes into closed loop. this is a common issue that can be hard to work out, The engine idles very steady without any idle advance so I suggest using as little as possible and fine tuning the idle valve control.
Just use idle advance to catch the falling idle or to lower the elevated idle.
- set the entire idle advance row to 16* right now in the datalog I see the timing [base not the correction] jump around as the idle settles, this is unsettling the idle speed
-leave the idle correction curve alone for now, we will alter it after the next datalog
-with the car warmed up you need to tune the VE1 table at idle, I see you are using idle VE and this is causing you many a headache right now. You want to setup the idle VE as the very last step and only if needed.
I am attaching a tune file with some small changes [ok large changes ] i think may help for you to try, as well as smoothing some of the tables for you.
I went ahead and split you out into two VE tables VE1 is everything out of boost and VE3 is in boost. I smoothed them as well, this creates granularity in the fueling. What i want you to do is load the tune I sent and run the car. Feel free to run autotune and let it try and get the fuel to fall in line for you then we can clean it up later.
Holy cow. Thanks. You're getting above my abilities right now with splitting the fuel tables. It sounds like I was trying to do too many things at once. It had a really weird issue before where it would idle fine when it was cold. But once it warmed up it would switch to the idle VE table and go extremely rich. So I was advised to turn off the idle VE table and just go off the main VE table.
Dumb question, but the idle section is 30-45kpa between the 700 and 900rpm section correct? I think I was looking at the table wrong before. I'm a previous SCT only guy so I'm still adjusting.
that depends on the car, you can have the ve table open while the car is running and just watch the blue dot it will show you where the engine is operating in at that moment.
Splitting the tables is just what i do to give more options, both do not have to be setup the same... the low load table can favor low rpm and then jump a thousand rpm at a time above 3500 and the high table can give more resolution in the high rpm area... this way you get more resolution where you need it.
I loaded up the tune you provided and it did good. I wasn't able to drive the car as it's been raining here and I try not to take this car on wet roads. For some reason when it's in closed loop idle control it won't idle below 1000rpm. I messed with the timing and the closed loop initial values and neither of them had an effect. I took a datalog of the idle and posted it. There's a quick rev as I was checking something else. If I unplug the IAC it'll idle at 600rpm.
So I played with the initial settings and by reducing the duty cycle I was able to get the idle where I want it. But that felt like a hack way to do it. The dot was hovering over the 1100 bin, but I was able to get it to idle at 800. Maybe I need to redo the RPM's on that table.
@a91what, sorry it's been a couple days. I actually wanted to try and get some data. I managed to get the car out of the garage today and drove it around the neighborhood. I took a cold start just in case. It was the first start up of the day. The main datalog is while I was driving around with and I had the autotuned running. I've never had an autotune set up and it was a trip to feel the car getting better as I drove it. The idle surge log is after I got back from driving. The idle was surging at stops. I'm not sure if it's wideband related or something else. The only other "issue" I noticed was the RPM dropped really quick between shifts. I think I saw somewhere to slow that down so I'll have to look it up again. I also attached a copy of the latest version of the tune.
yes, it was not entering closed loop idle
you may want to take a look at the engine state settings, first tab on the left. If it says overrun on the bottom of the screen at idle then your settings need to be tweaked. It should say closed loop idle at the bottom of the screen if it is turning on.
I just got done letting it idle for about 10 minutes. It was long enough for the fan to come on. Which I think I'm only getting low speed on. But I did see the CL Idle light come on. I did make one change to the tune you supplied. I had the VSS Threshold set to 0. I changed it to 1 before I started the car. It seemed to follow the closed loop curve.