No spark –> no fuel =????

[JSiN]

im hoping somebody can help me out with this...
heres the short- i acquired a second e30, and basically wanted to combine the two of them, ultimately making 1 great out of 2 good...so i began the much-involved process of moving everything over from my 87 325is, into my 91 318is...
so to summarize, i dropped my m20, with ecu and harness, into the 318, in place of the original m42... i wired everything up, connected the m20's c101 into the m42's c101... and when i went to start it....it cranked, but didnt turn over... a few things at this point i've noticed.

– theres no fuel getting to the rail, or better yet theres no power getting to the pump....
– theres no power at the coil, so theres no spark....
– a couple other things ive noticed is that most of my interior electrical is out...no cluster lights, no window power, no headlights, no blower fan....

now i do have turn signals, hazards, parking lights (actually just the front bumper parking lights, not the side-markers) horn works, interior lights work...

so at this point, im a bit stuck....i explained this all to a local bmw mechanic, and although he didnt have time to go into great detail over the phone, he did mention something about a 3wire plug, that is located right around the main ecu harness plug, that has something to do with the obc, and that if this isnt hooked up, (to where he wasnt exactly sure), that the car would have this exact same issues with the fuel/spark...

but then someone else told me something totally different, and pointed me in the direction of the c101 connector....

so does any of this sound familiar? anybody ever done this exact swap?
check this out...i have a BUNCH of extra e30 parts... and i will happily hook up whoever can help me get my car working...no joke...
anybody bored in the bay area?? wassup?!?!? :mrgreen:

thx for any help/info/advice offered...
peAce

[s52e30m3]

Check the etm's for both the cars and make sure the c101 has the pins in the same location, they made slight changes over the years.

[jlevie]

Your 87 M20 DME & harness require that the start signal be provided to the DME via a branch off the harness near the DME connector. Later cars provide that signal via C101. And there are a few other differences in C101 over time. As s52e30m3 says, you are going to have to figure out what the differences in the body part of the electrics are and either adapt your harness to that or replace that harness with one from a later production 325i.

[JSiN]

thats the 3 wire plug i was told about... and i guess the easiest way to fix that issue is like u mentioned, to replace the entire harness with a late-models... also, something else i was informed of is that i may have to replace my starter motor, also with a later-model...something about mine only having 2 prongs, and that i need it to have 3, and then run a wire to the unloader relay or something....
wow....im a bit stuck..i guess im off to find a late-model harness...and a starter...
anybody else know whats up with this???
thx

[jlevie]

All of that is correct. But you can work around the starter issue by forcing the unloader relay to be in the run state all the time, which is what was done on the 87 M20B25's.

[Danny]

Well swapping out the M42 was your first mistake.

[SpecM]

Well swapping out the M42 was your first mistake.

o rly?

[JSiN]

haha...u think i shoulda kept the m42?? why is that? hey actually danny i drove out to ur place a while back and we swapped wheels... judging from ur sig pic it looks u got some cool thangz goin on...nice!
anyways, so i got the engine started finally....it turned out that it was wire #2 in the c104 plug, which in fact is hanging off the 87's ecu harness plug in the g-box... it has something to do with the onboard cpu, and its ability to shut down the fuel/spark to prevent theft of the car... so i literally ran switched power to this wire, and voila!
but there still seems to be absolutely NO interior power, and no headights...actually my hi-beams work, just not the lows....still no windows, no dash lights, no fan...
anyone know what the prob is???

[SHADYB]

Which color wire and which plug off the harness did you run switched power to?

[JSiN]

hey....so its a small 3-wire connector called the 'C104" plug....and its located passenger-side in the g-box...it stems directly off the main wire harness plug that hooks to the ecu....it kinda just dangles right there up above that black plastic cover in the g-box....
anyways, so the 3 wires are one black, one green, and one yellow/white stripe.... the green one is the wire i ran the switched power to... and with that, the engine came to life...
so im still reading thru (trying to) the wire diagrams for both the 87 and the 91, and trying to figure out whats up with the other electrical issues that im still facing... so with the lack of all dash lights, windows, blower fan, etc, i also noticed that my tach gauge doesnt work either...

wheres that e30 electrical guru/pimp out there that has my fix??
HELP!!!!

thx

[JSiN]

so im still without most of my interior electrical.... i havent had tons of time to do much with it, as i've been laid OUT with the flu.... but im guessing that if theres someone out there that has a good understanding/knowledge of the e30's electrical system, and knowing the couple problems that im still having, that there might be an easy fix??

any ideas?
thx