M50 swap wont start :(

[jeds320i]

hey im almost done with my m50 swap into my e21, but it wont start and im gettin frustrated. even tho i dont have an e30, the principles are the same. i've double checked everything about 5 times and it wont start. its not sparking and the injectors arent firing. it cranks fine. im almost positive i wired it up right. im using an e34 chasis plug that i wired into my fusebox. in theory, wont the engine run if the ecu and everythin has power like its supposed to even if something in the chasis plug wasnt hooked up right? i grounded everything, i hooked up all the hot wires, the ignition coils have power but wont spark its like the ecu wont send the signal to fire ya know. well then i thought it was the crank or cam sensor. i got a new crank sensor and it tested the same as my old one so thats not the problem. i basically diagnosed it to being maybe a bad ecu but im not sure.. What do u guys think? i need some input thanks

[bimmerteck]

Make sure the DME isn't water damaged, I ran into a swap earlier this week where the DME was not commanding the relays, coils, or fuel injectors, it was pre-EWS so after checking power and ground I cracked the DME open only to find. . .

[Adrian_Visser]

Double check your relays are in the right spots as well if you swap the wrong relay into the dme relay socket shit won't work. You could just bypass the relay temporarily to check.

[jeds320i]

yea i did check the relays, when i picked up the motor from the guy it was all complete and he just pulled it out and didnt touch anything and the relays were all there and stuff. i did check the relays with a test light, all of them had power and the blue n orange one clicked. the main white one didnt click but had power to all the wires so i assume its working correctly. i better open my dme to double check its alright..

[Adrian_Visser]

Do you hear the ICV humming when you turn the key to the run pos.?

[Adrian_Visser]

yea i did check the relays, when i picked up the motor from the guy it was all complete and he just pulled it out and didnt touch anything and the relays were all there and stuff. i did check the relays with a test light, all of them had power and the blue n orange one clicked. the main white one didnt click but had power to all the wires so i assume its working correctly. i better open my dme to double check its alright..

I wouldn't skip that over if I were you the O2 sensor heater relay and the DME relay should click audibly when you turn the key. Bypass the relay with a piece of wire Looking at the side of the relay there is a schematic of what terminals are what. Put a jumper from relay socket pin 8 to socket 5 and another form socket 8 to socket 2.

[Farbin Kaiber]

Unloader relay issue?

[jeds320i]

ok i might have found the problem. i opened up the dme and while fiddling around with it a little chip fell out. i assume it was real loose. but i cant open up the two circuit boards to put the dam thing back in.. how the fudge do u get the top circuit board out of the pinout or w/e so i can open the two halves and put the chip back in?! diagrams and pics wood help!

[jeds320i]

i cant figure out how to get it out.. i dont wana pull to hard and break anything..

[jeds320i]

my ecu is a 402 btw, and i have a non vanos m50

[jeds320i]

ok i finally got the dam thing apart, put the chip back in and i still got nothin. i thought for sure that it wood fire but didnt. so i am really pissed off at this point. as far as that relay goes, i got power at all the wires so jumpering it wood be a waste of time really.. its gotta be working. any more suggestions?

[Adrian_Visser]

Another DME if that one had pieces falling out of it... Maybe it was dropped real hard and broke other stuff in it.

I was sort of worried about my DME since I dropped it right on the cement floor of my garage unwrapping it.

[Good & Tight]

Fuel lines hooked up properly?

[EricT]

When I did my swap this happened to me. It wound up being the ecu was dead. If you can find another one to try that would be titties. I pulled my harness apart and re wired it, swapped to another harness, and ran thru a whole ton of other shit before I tried another ecu....... then just wished I had just tried the damn ecu in the first place. My swap would of been done in about 6 hours. Instead I spent the next two days searching for issues everywhere else figuring there was no way the ecu was dead...

[jeds320i]

hmm. well i actually talked to the guy that sold me the motor and he had an extra dme that hes sending me. i mean ive checked everything and it seems like its the problem. i actually hope the ecu is bad then its an easy fix lol. i did hook up my fuel lines right. the chip that fell out of the ecu when i was taking it apart, im pretty sure it was the chip that many ppl upgrade to a performance chip ya know. well it had a label on it saying "91-92 bmw 325 525" and then the serial number of the ecu was below that on the label. is my ecu chipped?