M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Swaps, Turbos, Buildups => Topic started by: B318M42W on October 05, 2010, 11:31:04 PM

Title: my supercharged M42... issues
Post by: B318M42W on October 05, 2010, 11:31:04 PM
I just finished assembling my M90 s/c and decided to give er a try and see if she'll start...

She starts all right!!! however, it idles at about 2000 RPM when cold, then bounces between 1500-2000. also, once slightly warmed up, i beleive i have detonation? unsure of what it sounds like but it doesn't sound good!
took a short video, can mostly hear it by the end...

http://www.youtube.com/watch?v=VvwXr_DH8Co

A little bit of details:
- 5psi boost
- currently on #44 injectors with 3 Bar FPR
- 250 LPH TRE fuel pump
- 1 step cooler plugs
- STOCK ECU (piggyback isn't working:() (had a chip before, put the stock one back, ECU had no power for a few days)

other interesting facts... before i got the #44 injectors in, i tried to run 4Bar FPR with stock injectors. managed to idle at 700 rpm but was reallly lean
with the larger ones, it maintains a healthy 13:1 @ 2000rpm....


so my questions are:  - why is my idle so high???
      - what's that sound in the video and what can i do about it?

Thanks!!!!!
Title: my supercharged M42... issues
Post by: 1991 E30 M42 on October 05, 2010, 11:54:18 PM
did you remember to put oil in the engine?
Title: my supercharged M42... issues
Post by: dkbmxer002 on October 06, 2010, 01:07:14 AM
13.1 in a boost application is healthy?
Title: my supercharged M42... issues
Post by: bmwconnect on October 06, 2010, 02:09:29 AM
Injector part # please
Your motor will simply not run on 44# injectors unless you have decreased idle fuel pressure and or have changed the mapping

bring your baby up to Ottawa and I will tune it correctly for you before it blows up:)

midnight-tuning@rogers.com
Title: my supercharged M42... issues
Post by: bmwconnect on October 06, 2010, 02:30:45 AM
Quote from: dkbmxer002;97175
13.1 in a boost application is healthy?


for light acceleration this is a ok afr, but in boost for a supercharger 11.5-12.5 should be your target for safe operation with correct ignition timing
Title: my supercharged M42... issues
Post by: nuvolarossa on October 06, 2010, 02:38:24 AM
sorry, could you post some pics so we can see if there is something wrong in piping or setup?
you already calculated pulley ratio?

you need fuel (& ignition management if you can), either rrFPR OR stock ecu tuned for those injectors OR piggyback OR standalone.
Title: my supercharged M42... issues
Post by: fabe on October 06, 2010, 02:48:28 AM
the SMT6 shud work if you wired up everything correctly...
Let me go search for the wiring diagram. The new diagrams posted in the perfect power website is not user-friendly.
Title: my supercharged M42... issues
Post by: nuvolarossa on October 06, 2010, 05:55:44 AM
Since there isn't a SMT6 diagram for the e30 318is, I uploaded the diagram of SMT7 for E30 318is AND SMT6 installation manual.

You need to read the SMT6 manual to check the SMT6 pinout since they're different from SMT7 diagrams and follow the engine wiring pins from the SMT7 diagram.
Doublecheck them with BMW ETM if you can.

SMT7 wiring for E30 318is
www.studentipolito.it/download/SMT7-bmw318isE30.pdf (http://www.studentipolito.it/download/SMT7-bmw318isE30.pdf)

SMT6 Installation Guide V1_3.zip:
www.studentipolito.it/download/SMT6 Installation Guide V1_3.zip (http://www.studentipolito.it/download/SMT6%20Installation%20Guide%20V1_3.zip)


let us know.
Title: my supercharged M42... issues
Post by: B318M42W on October 06, 2010, 06:45:31 AM
I wish i could drive it to ottawa! however it's over 800km from here:(
i don't know the injector part #, greentop bosch.
AFR of 13.1 at "idle" and goes down to 8.5-9.0 under load (1200rpm)  
i'll post a pipīng diagram later today
I did calculate the desiered pulley ratio to get 5-7 psi, which i do have ( Pulley ratio is very close to 1:1 with crank)
I have an SMT6, with a comm problem along with a deep desire to chuck it as far as i can...

Thanks for the support!
Title: my supercharged M42... issues
Post by: fabe on October 06, 2010, 08:37:05 AM
this is the diagram I printed from PerfectPower's site when I installed the SMT6 few years back.. a more 'visual' diagram...

(http://img.photobucket.com/albums/v621/fabianyee/P1060547copy.jpg)

A total of 7 wires from the SMT6 harness would be used and 5 from the engine harness...
need to tap signals from:
- Power
- Ground
- TPS signal

And then cut 2 wires:
- AFM signal
- Crank sensor

This diagram was not compatible with my ECU diagram, so I have to trace the the correct wires.

But there was an issue with the crank sensor signal. the signal (after going thru the piggyback) seem to be a bit weak to be read by the ECU during cranking. Symptom was like a slipped starter (not too sure how to describe it). So I came up with solution using an electromagnetic relay. During cranking, the crank signal would be direct. and then switch over after engine started. it solved the cranking problem with just a minor dip in RPM during the switchover. Power for the relay is tapped from the ignition key barrel..
Title: my supercharged M42... issues
Post by: bmwconnect on October 06, 2010, 10:09:49 AM
Quote from: B318M42W;97190
I wish i could drive it to ottawa! however it's over 800km from here:(
i don't know the injector part #, greentop bosch.
AFR of 13.1 at "idle" and goes down to 8.5-9.0 under load (1200rpm)  
i'll post a pipīng diagram later today
I did calculate the desiered pulley ratio to get 5-7 psi, which i do have ( Pulley ratio is very close to 1:1 with crank)
I have an SMT6, with a comm problem along with a deep desire to chuck it as far as i can...

Thanks for the support!

says your in montreal? only 150kms away
I cannot help you till we get a injector part number...they are located on the injector
Title: my supercharged M42... issues
Post by: deekay on October 06, 2010, 03:08:54 PM
single-digit AFR under boost is pig fucking rich.

what did the AFR look like with stock injectors and the 4bar FPR?
Title: my supercharged M42... issues
Post by: B318M42W on October 06, 2010, 08:01:39 PM
4 bar stock injectors resulted in 650 rpm and a 16:1 AFR, and a really lean (around 18) AFR at higher rpm (not even load, just rev)

Thanks for the hard work put into the SMT6 issues, but i've given up on it since i can't get it to communicate properly (sure it would of been great to get it to work right, but at this point it's already wasted 9 lives, it's dead now... so far, the wiring i had was correct, i was using the ETM along with the developers manuel (has all smt6 wires and wire definition) to plug it in right and still no results. pretty sure the unit and/or the comms port is fried...)

Here is how she's all plumbed up!

(http://i729.photobucket.com/albums/ww298/B318M42W/Vacuum.jpg)
Title: my supercharged M42... issues
Post by: deekay on October 08, 2010, 02:09:26 AM
Quote from: B318M42W;97215
4 bar stock injectors resulted in 650 rpm and a 16:1 AFR, and a really lean (around 18) AFR at higher rpm (not even load, just rev)


i hate to say it, but i think you probably borked your bottom end running that lean. detonation is bad enough on a naturally-aspirated engine... with FI, it's pretty much instant death.

this is, if nothing else, a good object lesson in why research is key before undertaking a project like this.

fueling is not a matter to leave to guesswork or trial-and-error... and even the most cursory of research would have led you to find that a boost-dependent fuel pressure regulator probably would have been satisfactory for your power goals (@ 5psi positive manifold pressure).

sorry if i sound harsh... i wish you'd also asked for advice on fueling when you were figuring out how to mount the blower.
Title: my supercharged M42... issues
Post by: B318M42W on October 08, 2010, 08:56:08 AM
It ran maybe about 3-4 minutes total on lean conditions, under 2500 rpm before i put in the 40#. an RRFPR was considered but i didn't want to go that route running 90 psi of fuel in lines that were built for 45... already had a solid fuel line burst before. yes i could of done a little more research, however, the engine isn't supposed to see boost at idle (BPV) and run under normal conditions, ie idle with stock components. this isn't what quite happened. the aim of the start-up was to check idle, not drive the car.
Title: my supercharged M42... issues
Post by: B318M42W on October 09, 2010, 06:09:35 PM
Got some progress!! I got her to "idle" properly when the AFR is in the correct range.

I know a lot of you are wondering why the engine even started with 40# injectors in the first place. Barrie from midnight tuning help enlighten me: I have the LC-1 WBO2 kit installed and apperantly it can somewhat trick the ecu into dumping less fuel.

This sparked the idea of vacuum leaks. unmetered air entering the engine along with extra fuel would result in a better AFR, higher rpm (idle) and a wondering idle. Soapy water revealed massive quantities of air leaks. took it apart and back together with an extra care to avoid any leaks, fixing any holes in the fabbed manifolds. No air leaks this time. The result: a really rich start, to the point it won't idle unless i play with the fuel pump (on/off), when turned off, the AFR gets leaner, engine runs smoother, nice idle when AFR is around 12-15:1 then idle goes to hell when fuel pump is just momentarily on and AFR goes back to 9:1.  will post a video shortly.

So now i'm starting more and more to think that i wasn't so crazy to try and see what would happen with stock fuel system. pretty sure i would of gotten a nice steady idle if it wasn't for the massive vacuum leaks. No boost at idle, -20"Hg PSIG

conclusion: check for vacuum leaks before doing anything, even if you're positive there ain't any.
Title: my supercharged M42... issues
Post by: bmwconnect on October 10, 2010, 01:18:03 PM
Yes this is true the LC1 can simulate a narrow band signal when correctly programmed and wired up witch will allow fuel to be pulled but the computer can only pull so much so the car will still run very rich foul plugs quickly and thin oil out... standalone or tune is the only way to solve the problem
Title: my supercharged M42... issues
Post by: bmwconnect on October 14, 2010, 12:38:32 AM
Thanks for making the long trip!! cool setup and car runs mint with your new tune!!
have fun!!
Title: my supercharged M42... issues
Post by: B318M42W on October 14, 2010, 12:47:59 AM
It was well worth it! The car drives great, smooth idle and hard pull all along the rpm range. this guy knows how to tune a car! Really great to work with too. Lots of support before and after the tune also, wich is a really good thing. I highly recommend using his services for any tune.

thanks again!