need help with ms2 extra code

[der affe]

i have been running ms2 for almost a year now with no issues other than getting the firmware installed with was a serial port issue.



earlier in the week i went to leave after the car had been sitting all day and it would do the crank no start thing and the fuel pump was not priming. i went to the relays and grabbed my spares. swapped them around to no avail. i then took the red jumper wire that goes from the #30 to the #86 (it is pinned into the spade of the relay) out, retwisted and put it back it. BAM problem fixed!



today i went to the store and when i came out, same thing. this time it did not fix it. i called a friend and we towed it home the 5 blocks to my house and i let it cool off.


tried switching the relays around and got out the power probe. with the key on, i have power at the #30 and at the #86. i can also trigger the fuel pump with the power probe using the middle relay.

next i took the cover off of the ecu and cranked it. none of the lights light up on the MS2 when i crank it or with the key on.


i also have an extra CPS that i swapped in, just incase and still no change.


i am about to check the bolts to the ECU mount as i think it uses those for ground.


getting ready to plug the laptop into it also to see if i can see what is going on.


any other hints or ideas.


i am wondering if the ecu might have lost the tune????????


all the tests for a stock system seem to be comming out ok.

[der affe]

the plugs are dry too.

[whodwho]

Sounding like no power getting to the ECU, did the laptop connect?

[der affe]

no power to the ecu, ms does not light up, can not connec with the laptop.

could the ignition switch be going bad, intermittant issue?

i have crank and power at the dash and can trigger the center relay to make the fuel pump prime as well as hear the relay for the fuel pump click

[der affe]

it is the orginal ign switch as far as i know, maybe the orginal to the car

[whodwho]

Have you tried to jump the main relay?

[der affe]

which one i that? sorry, i am really beat after a now shitty day.

one of the ones next to the fuel pump relay? if so yes and i have power at 30 and 86 with the key on. i can trigger the fuel pump with my power probe using the middle relay (orange) next to the fuel pump relay (white one)

on top of that, it just started when i turned the key and is running now.

thinking ignition switch now because of that.

i am connected to the laptop now also

[whodwho]

Not sure it is the ignition switch If the dash lights come on??

[der affe]

yep, and now it fires up and does its thing like it is supposed to. fucking intermittant shit!

i have ran into similar issues on other cars. like something is not completely right inside the switch.

i went and giggled wires while it was running and could not get it to stop running or hiccup.

[Jaxx_]

if you couldn't connect to the ms box, you didn't have power. when the box gets power the leds should flash, and the injectors should fire their priming pulse.

check the grounds too, don't forget you have to sink power as well. ;)

[toointoxicated60]

Is it a v3 board or v3.57? If its a v3 was the flux cleaned? I had some funky stuff happen to electronics because flux that was never removed.

[der affe]

It does not seem to be an issues with the MS. BUT I am not getting power to the ecu.

I spent the day checking wires and grounds with it now working and counld not get it to duplicate the problem.

So I went to the store and the dam thing did it in the parking lot! Great!


Now my question is.....does the power for the ecu run through the ignition switch? The car cranks, the dash lights up, but now power to the ecu. If so, that is the last thing to try.

I know that they will randomly die as they are going out.

Just want to comfirm before I replace it.

[jlevie]

I don't know how your MS is set up as compared to the OE DME. But I do know how the stock system works.

The stock DME gets unswitched power on pin 18 from the small cable that attaches to the battery positive post. That cable also supplies power to the main relay. The ignition switch is powered by the main battery cable and when the ignition is on supplies power to the coil, injectors, and START input (pin 27). When the START signal is present the DME ground the coil of the main relay which then supplies power to pin 37 of the DME.

The small cable from the battery includes a fusible link. That link can become corroded and cause problems.

[nando]

ok now I have a keyboard instead of a phone :)

your MS is wired up just like a stock ECU. as Jim says, the ignition switch supplies the ECU with a "start" input which then turns on the main relay.

Did you ever have a chance to open it up?

I would check the wires and pins at the main relay. Maybe something is loose. Also check the pins and wires in the adapter harness. You should be able to get full continuity from pin 85 of the main relay, to pin 37 of the adapter harness (i don't remember which pin I connected that too on the MS side, but it was either the SPR pins (3-7) or the IAC pins (25, 27, 29, & 31). If you follow the wire from pin 37 of the motronic connector, you should be able to figure out each one.

also open up the MS and look near the 3 LEDs. the "proto" area is where the relay transistor is located. Since it's working sometimes I can't imagine the transistor is the problem (they usually pop like a fuse), but it's easy enough to have a look.

and of course, the ignition switch *could* be bad. Dunno. Never had that happen yet.