E28 Megasquirt FAQ

[alijonny]

Hey, it's not a problem at all. I am extremely thankful that you made a pinout when you could have stopped at the 55 pin-out.

[alijonny]

btw, I forgot to write about the noid light deal. lol. I put 2 of them on this morning and 1 and 2 cyl and when I cycled the ignition the lights both came on solid and bright. it was awesome. I could see everything in the small crevices the light was so bright.

I don't have a downpipe hooked up right now so I can see what is coming out of the exhaust and It was pretty interesting seeing fuel getting sprayed everywhere. no fire hazards here...

[alijonny]

alright! all is working except for the tps sensor.

[Brad D.]

I have found that the m30 tps is a bit different. Mine did not have the braided ground. You want to use the yellow, black and brown wires.

Brown - ground - splice it into any available MS ground

Yellow - signal - splice this to the tps signal in pin on MS

Black - 5V reference power. MS has a 5V reference voltage output.

[alijonny]

done and done. now waiting for coolant and radiator cap from BMW.

[alijonny]

alright a few quick questions:

grounds: I wired my grounds from the Motronic box straight to the db37 connector, I noticed pics of turbodan's (I think) setup where he has the grounds on eyelets going to the body. should I do it this way also?

Idle control: Brad, I notice you have an option to input actual frequency as seen in the pic on the bottom
MS2extra has a different option where you enter a number from 0-8. WTF?
Also the car will start and surge slowly from 400-600 rpm and eventually die, I can try to give it some throttle only to kill it. It will start back up. I tired changing the idle control settings with no help, the car seems to be running edit> LEAN by the looks of the WB (about 17) Any ideas?

[Brad D.]

A wideband reading of 17:1 is lean. Remember for gasoline stoichiometric is ~14.7:1. Anything below this considered rich, above lean. That is probably far to lean for it to ever idle right. Try it around 13:1 and begin to lean it out until the quality of the idle goes away then richen it back up, say half an AFR point. The screenshots are from my earlier beta code. The box you are referring to is a scaling multiplier. The frequency will be the value you enter times 30.5Hz. At my setting it valve works in 1% steps. This probably isn't a major factor right now in your idle settings. It can be used to increase or reduce sensitivity of the frequency to aid the PID.

[alijonny]

my bad I meant lean. let me play with some numbers tomorrow and see what happens.

[mooseheadm5]

The reason it starts up again is because of the priming/cold start squirts that give it enough fuel to run for a short time. As BBR says, your motor is running super lean.

[alijonny]

I have the priming set at 0 across the board

[mooseheadm5]

It must be running off cold start then.

[alijonny]

It very well could be. Anyone with larger injectors find it necessary to use the priming pulse? I know I haven't had the car running long enough to do warm starts, so I don't know if i need to consider plugging some small numbers in.

[Brad D.]

[alijonny]

ok, it starts and runs but really lean. like 19-20. it idles at about 1300 rpm which is a bit too high and if I try to make any changes nothing really happens. what am I doing wrong?

[mooseheadm5]

VE table? Improper injection flow rate setting? How is your fuel pressure?

[alijonny]

all tables are going by what brad has posted on the first page. The fuel pressure I don't know. N/A everything was just fine, however I have not checked the actual fuel pressure or flow since I have owned the car.

req fuel is set at 9.0

[Brad D.]

What size are your injectors?

[mooseheadm5]

And what type are they? Have you got lowZ injectors in there?

[alijonny]

42lb green injectors 14 Ohm PN: BOSCH 0280155968 EV6 body Ev1 plug

[M. Holtmeier]

I wonder if the wideband is programmed correctly. The car wouldn't idle at 19:1. Also, remember that the sensor cannot measure unburned fuel. So if you're way too rich you may be getting a false reading.

[alijonny]

possible... however I calibrated the WB according to the instructions for open air calibration. Nobody answered my questions about grounds, might that be causing the problem?

[M. Holtmeier]

possible... however I calibrated the WB according to the instructions for open air calibration. Nobody answered my questions about grounds, might that be causing the problem?

I grounded mine the sam way you did, except I did make a complete seperate ground for the sensor heater. Double check your wideband settings, double check the ms settings. Make sure that the voltage params are the same and that megatune is set correctly as well. Seemed like on mine when I first getting things set up, the lc-1 wanted to lose it's voltage parameter settings. I must have free air cal'd that thing a dozen times. Just to get the car idling and moving, turn off the idle and just bump the throttle open a little with the set screw. Get the fuel map set up a little first. I've got 60 lb/hr injs and my priming map looks about identical to Brad's. I use all the tables I can for cold starts, so you'll have to go back and mess with it over and over, but it's got to pull from a correct fuel map. If you have some numbers in the fuel map already, bump the req fuel up until it stays lit, then when it's warm you richen the fuel up and set you req. fuel back to where it's supposed to be.

[alijonny]

sometime monday, I am going to check the timing from the crank and re- calibrate the WB. I am going to hook up my fuel pressure gauge and see what that is sitting at and go from there.

[alijonny]

should I have my VR sensor setup for inverted or non inverted?

[FirstFives Dictator]

should I have my VR sensor setup for inverted or non inverted?

Depends on how you wired it; if it syncs and you show rpm, you've got it set right (MS2 extra - MS1 is more promiscuous and tries to sync on just about anything)