rhombus

I have a 04 MSM with the FM little enchilada kit and a wideband, no o2 modifiers or anything like that, VTCS unplugged, stock injectors. On the stock ecu, AFR are 12.1:1 to redline @ 9psi on wastegate.

Yesterday I installed a brand new MSM0405 MSPNP Pro unit. Set timing offset, set the WB input, fired right up. Went out to start tuning and it was going super lean above 4-5k (16-18afr) under boost. I added a ton of fuel in the VE map (kept adding until it was in the 200s) up in that area, no change. The MS reports over 100% injector duty cycle. In fact, it is at 100% DC in the midrange under boost and stays there as I see the AFR creep up in a pull before I let out.

I have done a ton of reading to find an answer. I tried changing it from 2 pulses of fuel to 1 per rotation thinking the added deadtime of multiple pulses could be causing a problem, I tried messing with the dead time (it was 1.0 in the basemap). Boost cut is disabled, I dont see any fuel cuts enabled. I feel like there must be something in the tune or basemap to cause such a huge difference in AFR. These cars are supposed to be able to run 9psi on the stock fuel (and does on the stock ecu). Is the injector timing off in the basemap? I put the stock ecu back in this morning, ran fine.


Why am I running out of injector so quick on the MS? Can someone take a look at my tune and see if there is anything they see wrong in the setup? Does anyone have a working map for stock fuel on a MSM I can try?

@Ben



I have a set of FF injectors that I will eventually put in, but I feel like it should run properly on the stock injectors and Id like to get it running good first before I change more.

Thanks,
Rhombus

18psi

iTrader: (76)

12.1:1 afr on stock ecu is also very lean so the issue isn't just with the ms

rhombus

12:1 really isnt really lean, especially for a near stock boot level on a factory turbo car. I will also add that at peak TQ, it was 11:3:1afr and tapered off to 12:1 at redline. This is pretty common on most factory turbo cars that I have seen. At higher boost or power levels, sure lower the AFR in the tune. Im in complete agreement that the stock injectors are near maxed out at this level. Most MSM out there have the little enchilada kit mods on them, they are not melting pistons left and right at 9psi even when they run them on the track.


The point is that the MS should be able to achieve the same AFR as the stock ecu. My question is why is it not.

18psi

iTrader: (76)

12:1 is lean because a factory msm triggers and achieves 10's afr up top. If yours hits 11's then tapers up then its probably losing fuel pressure and you probably have a fuel system issue, and ms is not going to overcome this issue. with bolt ons you should easily run up to 10psi on stock injectors and maintain high 10's low 11's afr even seeing 123% IDC (I've posted all about this years ago).

If you ask for help and then pretend to know what you're doing in the same thread no one will want to help you

rhombus

Fair enough. Im here with an open mind, looking to solve a problem. I have 20 years of tuning experience, not just an "internet tuner". I am looking for help on something that doesnt make sense. I appreciate the help.

My main question is why cant the MS at least duplicate what the stock ecu is able to do? What is different in the way its controlling the injectors?

18psi

iTrader: (76)

will look at map when on personal computer. probably a fueling cap or some other setting

you don't have progressive fuel cut rev limiter do you?

DNMakinson

iTrader: (3)

Are you reading the AFR from the same place? In other words, from a stand-alone WBO2 sensor and gauge combination?

rhombus

Yes, and my innovative gauge and the MS both match in values.

rhombus

No. Progressive is disabled, normal fuel cut limiter is enabled. Limiter set at 7200 and soft limit zone 200.

DNMakinson

iTrader: (3)

I'm not seeing anything in the tune related to issue. What FW version are you running?

I would change AFR/EGO algorithm from "Simple" to "PID"; and MAP Averaging Lag Factor to closer to 90 (unless you are seeing sawtooth); and Injection timing to 400 or so everywhere. Won't make a difference at 100% DC, but could help when injectors are opening and closing.

You might post a log of the issue.

Is MAP sensor reading making sense, i.e. very near 100kPa with KOEO, but around 30 kPa at idle? Meh, NVM: 100% DC is 100% DC. But, some older versions of FW reported inflated DC numbers.

Seems indeed like running out of fuel, and then your question is obvious... Why is MS3Pro different from stock.

rhombus

Attached is a log from last night. 2 Things I have noticed, the VSS was set for 40000 pulses per mile in the base tune off by a factor of 10, and my IAT sensor is not reading correctly. I dont think either one of these should limit fuel when its going well over 100% DC.

DNMakinson

iTrader: (3)

I did note that it has engine states, so it is 1.5.X FW. VSS is not involved. Interested in how this plays out.

rhombus

Yes, 1.5.1 FW

DNMakinson

iTrader: (3)

So the FW is back to reporting more than 100% DC. But it is calculated correctly, and supposedly sending longer open times than actually exist between events.

Yes, IAT is all wrong and calling for lots of fuel.

There have been no bugs reported on this kind of issue.

Indeed, once you hit 100% DC, you appear to be getting no more fuel, and thus leaning out.

The only thing I could imagine you could try is to go to 1.4.0 FW, which is known to work correctly. Otherwise, put a scope on the injectors and see if the PW shown by TS matches what is really happening. Not real easily done. And as many people who have run JimStims (sp?) on MS, I find it hard to believe that PW does not truly go to Always On at 100% DC.

I have no more. @Braineack, can you bench test a MS3 and see if 100% DC gives always on to the injector outputs?

18psi

iTrader: (76)

Braineak no longer builds these or works on them.
1.5fw works just fine. I have several cars running it currently.

DNMakinson

iTrader: (3)

18, thanks. I guess he mostly focuses on the political thread

Do you think it could be a resistance issue causing the injectors to not open fully? Seems like sense a PNP, that would not be an issue. There is also a setting for choosing output "InjA" vs "Inj I" or some such setting that I am not familiar with.

This is an intriguing situation. I keep thinking about it, even though I don't really have a clue. I will again try to leave it on the table and come back Monday to see if you come up with anything.

Nice to have you back. Hope all is well.

rhombus

Here is my latest theory.

I have only had this car for a few weeks, so I am still going through it. When I was driving it home, i noticed the TPS unplugged, I plugged it back in and it ran worse, so left it unplugged. This prompted me to go ahead and get the MS for it so I could get the car running proper the correct way.

Stock ECU, car had the TPS unplugged. With the TPS unpluged, the ECU probably doesnt disengage the alternator at WOT since it doesnt know its at WOT.
Install MS, plug in TPS. MS controls alternator and disengages it at WOT. Voltage drops and fuel pump doesnt keep up.
Logs only show a 0.5V drop at WOT, but perhaps there is a larger drop at the pump itself.

I ordered a new fuel pump and will put it in tomorrow.

rhombus

Just did a test. Fixed a few mistakes identified in the basemap ( IAT, VSS, changed the fuel pressure settings to fixed and 60psi) and set the alternator voltage to 14.4. AFR maxed out at 13.5 vs 16 before.

My research seems to point to NB fuel pumps have a hard time keeping the pressure at 60psi at redline even stock, this pump may be tired. I have a fuel pump coming tomorrow, so I hope that solves the issue. If it does, Ill swap in some bigger injectors.

curly

iTrader: (25)

So your voltage correction is wrong? You may want to check that.

irodd

iTrader: (4)

So DIYAutotune basemap still has:
VSS 40000 pulses and Injector Timing table = 90 degrees