Turbo M42 timing table

[aeroeng]

Hello there.

Does any of you happen to have the timing table for a turbo m42? I really need it for reference. I'd be happy to also reference an NA M42 map if that's an option. Part of it is the idle that I cannot get right. If anyone can share an m42 map with me I'd really appreciate it.

[Dj Buttchug]

I have one. Its going to be different for you depending on what you are doing. Ill try and upload it here tonight.

[Dj Buttchug]

Tell us more about your ECU. What are you running. Are you using an icv? Idle problems are usually related to lean conditions. What is the idle doing exactly?

[aeroeng]

Thank you for the table. Here is my setup:

MS2 v3.0
Stock e36 M42 ICV
GM 3 bar MAP sensor
GM IAT sensor
Bosch Green Giant 42lb injectors
AEM UEGO 30-4110 wideband
Stock Crank sensor (not using the cam sensor)


I did get the idle to stabilize at around 8-900rpm. First it was idling at 1500 rpm, but then I swapped the ICV and it started working properly. I actually took the car out for its very first turbo test drive and attempted to autotune a little. Overall the ride was fine, and AFR was mostly on the rich side (playing it safe). During the drive I had something weird happen a few times tho - the engine RPM would momentarily drop and pick up again, it was both loss of power and the tach also did a quick dip. I thought it was a sync loss or some interference with the crank sensor, but after like 5 minutes of driving and autotune, it stopped happening. Not sure if it was something with the fuel table and was tuned out...
Anyways, it was super exciting and I actually hit around 5-6 psi once the car was acting normal. Not sure what the exact AFRs were, but I know they were super rich during the pulls, THe AEM would max out at 10.0, so it was below that.

I'll hopefully keep working on it next week once I'm back from travel and report back.

[aeroeng]

To answer the second part of your question, the idle used to go from stable to hunting out of nowhere, and nothing would help it. I think it was still doing it last I checked, but it was a much smaller change in rpm, maybe around 100 rpm delta. Now I'm thinking back and I think I experienced the hunting idle only after 10 or so minutes of running (on hot engine only) which makes me wonder if the IAT is getting heat soaked. But then again, that would only makes sense if the car started running leaner, but I don't think that was the case according to my wideband.

BTW, here is my setup. The IAT sensor is on the front side of the intake, right after the throttle body.

[hasa]

First start using logging. Debugging engine behaviour is not possible on the road.

[Dj Buttchug]

Couple things to keep in mind here.
1. A good portion of your idle issues could also be from ICV setup in MS2. There are specific settings here for max open and max close of the ICV. Youll want to tune those correctly so the IVC is allowing the correct amount of air in the engine and idle as well as closing at the correct times. In other tuning platforms it is called minimum and maximum clamp. Make sure on the new ICV these settings are correct. If you go into the Mega Manual there are step by step instructions to tune this.

2. Check your required fuel. For that engine with those injectors ( I am running the same 440cc in my engine) you need to have a required fuel of 14.5. Work your VE table off of this.

3. Do not try and tune anything else until you get the VE map tuned correctly. If you do youll end up having to go back and do it all over again if the VE table isnt right. This goes for WUE ( warm up enrichment) AFR targets ect ect.

4. If you havent already, Get the car running idle smoothly. Make sure you have your cranking settings correct Cold and Hot so the engine will start without excessive cranking ect. Once you have a stable idle when fully warm then you can start running auto tune featuers to help get your VE table correct.

Hopefully this will help. If need be I can send you a VE map as well for 22psi. You can adjust accordingly. Since you are a running a GM MAP and 440cc green giants your tune is going to end up quite similar to mine.

Also. Make sure you go in and enter your injector dead times if you havent already. I have the latency chart for that as well just need to dig it up. There should be a spot in MS2 where you can add this in the injector setup drop down.


Check and confirm the required fuel is correct to fix the rich conditions. It is likely your Req fuel is wrong. You can only put 14.5 MS (miliseconds inj open time) into that engine. It wont take any more if it doesnt spin faster than 7200 rpm. This number wont change.

Once you have that set right go back to your VE table and re-tune the idle at fully warm. M42 M44 engines like to idle richer than others (This is just my findings over the years of tuning) To get a decent stable idle that feels happy my engine idles around 12.5 AFR fully warm. The only difference here is I am not running an ICV. This could change for you depending on your minimum clamp (the minimum percentage the ICV will stay open to allow enough air into the engine when idling)

[Dj Buttchug]

To answer the second part of your question, the idle used to go from stable to hunting out of nowhere, and nothing would help it. I think it was still doing it last I checked, but it was a much smaller change in rpm, maybe around 100 rpm delta. Now I'm thinking back and I think I experienced the hunting idle only after 10 or so minutes of running (on hot engine only) which makes me wonder if the IAT is getting heat soaked. But then again, that would only makes sense if the car started running leaner, but I don't think that was the case according to my wideband.
[/ATTACH]

Once you get the above sorted out then we can look into IAT. I find that addressing issues in steps is easier because there is less confusion, and you only make changes to one portion of the tune at a time.

IAT settings in MS are adjustable. As the intake air temp gets hotter the IAT table will allow you to pull fuel away (inj time adjustment) It's not abnormal to see IAT temps in the 130ish range so dont worry about this too much until the rest of the tune is built. IAT will have little effect ( if any) on engine idle characteristics. The idle hunt is from incorrect VE table and ICV settings.

[aeroeng]

That was some great information. I will definitely follow it step by step. Will really appreciate if you could share the injector dead times - I did look for them, but could not find a trusted source and went with something I saw on forums (dead time of 0.8ms @ 13.2V, and battery voltage correction of 0.2 ms/v). I just checked my required fuel and it's at 7.0 (I'm using 430 cc/min for flow rate since that's what 42 lb/hr translates to and 2 squirts per cycle). As for the ICV setup, I used the idle valve test tool to determine the fully closed and fully open positions. However, I need to admit that I did notice the RPMs were different when using the test tool at 30% duty cycle vs car running at 30% duty cycle while using the Duty vs Coolant temp table. Will need to investigate that further.

If you could share your 22psi table it would be great. I definitely could use it for reference.

[aeroeng]

I got back to the car and got it running today. It would not idle at first, but then I played with the idle valve settings and got it to start up and idle without touching the throttle (although the first couple of seconds it seems like it wants to die). From the logs, after start RPMs jump to 1300, then come down to 450, then up to 1000 and back down to 600, and eventually smooths out and idles at 900. Logs show that the AFR is super rich for 2 seconds right after it catches - not sure if that's how all cars are, or maybe that's the purpose of afterstart enrichment? I'm not able to attach the datalog for whatever reason.

More to come this weekend...