2014 Ford Mustang 3.7l procharger - new pcm part throttle (OL) inject cut
I'm at an impasse on this. simplify the back story, narrowed down part throttle issues to the stock pcm glitching out the o2 readings. put in new pcm using ford FDJS software, re licensed tune to car. set tune to basic maf transfer mode so don't pick on the 02's, wot lambda, etc. Now it won't accept anything over part throttle - and I was definitely not adding full throttle as wot as wet to 1.0. log shows that as the pedal position D closes on 50% the throttle position ramps up till it forces 81 deg max open and hangs there which is not good when WOT is set to 1.0lambda for test purposes. then for some reason the car goes into injector fuel cut, goes 1.4lambda lean and throws P0300, P0301 and P0305 misfire codes and sticks there, cars useless. have to turn car off, clear codes and then I can limp the car around -which it runs great below pedal position D 50% throttle. Tore out both harnesses on the engine and verified that injector plugs, coil plugs and 02 plugs have good circuits, all good. checked all spark plugs, all good. put in new ones just for giggles. all good. it idles so smooth right now it's amazing. So is it a PCM issue or does the new pcm need a new tune even tho everything else is equal? Log and scan file attached. AGAIN _> Don't mind that the 02's COT is off, wot lambda are 1.0 etc. I wasn't trying to go WOT, just get the car back up and running on the new pcm.
while waiting on the hive mind, it occurred to try softening the driver demand to see if it improves throttle match. Will update with news on that later.
Need to tune your SD load to MAP scale of MPs 7,8, and 9, not just raise the maximum values it can calculate too, if you don't want your throttle opening as it is at part pedal. You can do it in the TB model if you find the SD to frustrating, complicated, or time consuming, but transient fueling will be wrong and you put your self at risk of knock prone tip in if you are not running high octane fuel.
65% load is giving you calculated MAP above calculated baro (AKA boost). Because of this your torque values are wrong, and the ECU is probably not happy with the torque ratio. Your engine is probably more efficient than that so MAP shouldn't be as high for 65% load. I highlighted in the HPT SD calc where you would need to raise the load values. Its just a spot, but keep in mind the coefficients take into account the entire MAP scale, so in order to get the HPT calc happy you would need to adjust the entire column of values.
example if you want 28inHg MAP from ~90% load instead of 65%, you would multiple the entire column by what it takes to get 65% to 90%, ~x 1.33. Doing this would give you new coefficients that make MAP only come out to ~21inHg at 65% load, which is what you are getting at 50% throttle. As RPMS go up calc MAP may increase and the throttle would open unwanted again, so you will have to work across the RPM range and multiple MPs to correct what you are seeing. It really helps to log an actual MAP gauge.
Murfie,
I am excited about the advice you bring as always - the speed density driving throttle opening matches the experience. I am also stumped! Can we go back a few steps on how to get to this point? I am all in on learning to do solid density tuning. Where is the speed density calculator located, which engine tab? I updated to the latest non-beta before doing the log posted and I see some differences in how the tabs are laid out. but there's not one that jumps out as "speed density calculator". All of the ones under the tab posted are 2D tables not 3D tables, see attachment. To make sure it wasn't rearranged I fully explored the new interface before posting. I concurr with getting a 2 or 3 bar MAP sensor to plug into the PRO ports on my interface for logging.
*edit* Found the calculator. - Edit->speed density calculator. looked back a file history and it's never been touched to the extent that I'm aware of.
So here's two logs. One where it ran perfectly fine as long as I passed through 50% throttle and was very eager to rev. did back and forths in a parking lot incase it cut injectors again. and then there's the drive home where when I held 50% pedal position it snapped the throttle open, went lean and was useless till the car was keyed off, codes cleared. then drove below that pedal position the whole way home no problems. I've ordered a new pedal assembly to rule out that there's a dead short at that part of the sensor.
In the mean time can you verify if the speed density updates you suggested changed the nature of the problem or not? I'm still not sure what I'm looking at for this.
Also, I set up the 1st pro port to record the boost gauge (which is in the intake side) as a MAP sensor. Can't quite seem to get it to read correctly, tho. It's a prosport evo 52mm gauge and they didn't provide the scale/offset. I tried a rough calculation but that just pegged. The PLX seemed to read the closest so it at least shows trends which appear to track the cars sensors well. Just take the readings with a grain of salt till the pid is defined better.
I got your sensor to read what the calc. map comes out with no problem. There are a few areas that are wrong right around the transition into boost in the manifold still. The tricky thing here is your charge pipe could be getting to a much higher pressure than your MAP due to your centrifugal supercharger, thats where your MAF sensor is. If MAP is determined to be above baro, the TB model is going to open the throttle to prevent this, or the effective area is going to increase doing the same thing. You have your WOT start and end at 542, I would raise this to 1023 and 1023 to get the full range of your pedal torque based.
After doing some of the tune changes to no avail and chatting offline with Murfie and another 3.7l guru I logged for the misfire. and it appeared to be genuine. I did a lot of wiring diagnostics and finally found that the grounds on the upstream o2's were reading an intermittent open condition and high resistance when the harness was hot. replaced engine harness and relogged tonight. First off the misfire is still there but the big change is that the fuel trims track each other more faithfully. the banks were swinging wildly opposed (one rich, one lean). Now they track the same direction consistently. It also is showing that the area of the maf period table that it misfires is now consistently pulling fuel and also when it returns to idle it pulls a TON of fuel. not sure why for all of that but it's progress. I'll update the maf transfer tomorrow and see what that drives.
update... ngauge indicates that cylinders 1 & 5 are still the source of misfire despite replacing spark plugs, moving coils around and verifying that the fuel injectors have good impedance. and of course the harness is brand new so no wiring issues back to the PCM. compression leak down was good. I'm hoping it's just over fueling due to the bad o2 ground.
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