E30 S50 no start - no spark/no fuel

[sweet3]

The fuel lines are one of the easiest mistakes that can be made. Check your fuel lines. If you pressurize the tank, you will find the "return" line. The feed line is the line that is connected to the fuel filter near the back of the car. The feed line needs to go to the fuel rail closest to the firewall.
Hope this helps

[Classicoe30]

My friend had a the same problem! At first It would crank but wouldn't turn or run I should say! And all of sudden it would even crank anymore! Everything was check for connection and re checked again! The problem was in the ecu the war chip was not making full contact ! Problem solve! I would recommend to check your ecu and programming ! Good luck !

[Maschine3]

Will PayPal $ to someone with an answer

Anyone in Wisconsin who knows the e30s50 swap please help. Crank but not starting. In addition to my last post I got a new red label dme and new engine harness and still having issues. I live in Appleton, WI. I am serious and will PayPal money or pay cash to the person with answer or help.

[Maschine3]

Solved?

I have the exact same problem. The E30S50 cranks but won't start. Double checked all wiring, grounds, relays, fuses, chip for ews, and dme is good. How did you solve your problem? Thanks in advance.

[M3PO]

I don't think the OBC relay will be my issue, Im getting 12v to the main relay and my ICV buzzes and everything that the main relay turns on has power... just no FP relay action :(

You can test the functionality of the FP relay by using a piece of wire to ground the 86 pin on the relay. This is what the DME does to trigger the relay. If the pump kicks on, the relay is good and the issue is related to the DME.

In my case, the DME was not triggering the FP relay because EWS was telling it not to. :hitler:

[wakdog]

I don't think the OBC relay will be my issue, Im getting 12v to the main relay and my ICV buzzes and everything that the main relay turns on has power... just no FP relay action :(

[Matt-B]

Yea, my m42 years ago did this, dug into stuff to find pointless wiring lol

[e30austin]

Now I know this. Just seemed lame as fuck to me.

[Matt-B]

They still come wired, mine is, just no obc

[e30austin]

It was the fucking OBC relay in my case. Even though the car was a 318i with no OBC lockout...

[wakdog]

Im having a similar issue that has come up on my S50 swap after I replaced my fuel pressure regulator.

Car was running perfectly for 3 months prior to changing the FPR (apart from it pushing fuel into the intake through the vac line when idling for long enough)

Put it all back together and now I get no fuel pump prime (fuel pump runs when I jump the relay), no spark and I have a Code 26 on my scanner for 'Control Unit Supply B+'.

Things I have so far tested that have not helped:

Replaced DME+FP relays from my other car
Checked fusible link
New crank pos sensor
Checked continuity on power to DME (pin 26/54) + these wires have 12v at source when ign is on.
Car runs a Silver 413 with EWS delete chip, also tried a red 413

Im basically at the point where I think its time to give up on this harness (it came with the motor and had all the Auto wires cut which I cleaned up and removed the auto harness connector a few months ago).

[Wanganstyle]

from our race car a 24V swap E30 (obd1 413 dme) only needs a few things to fire:

crank position sensor
coolant temp sensor - the one in cylinder head that goes to DME not the cluster one; DME could care less about what the driver sees.

Things that can be left unplugged:

AFM - car doesnt need it to drive around in limp mode
Camshaft sensor - not needed to drive around in limp mode
TPS
IAC - BMW DME is smart enough to idle without the IAC if there are no vacuum leaks;
Vanos
Speed sensor
Intake Air Temp sensor

Things you absolutely need:

A functioning starter - external push button start is made by longacre and really useful for race cars or testing swaps. (ours is race car with swap so naturally used it)
a functioning Fuel pump - fuel pump is easily jumped with a 12V power source directly; if the car is a early car with external fuel pump its super super easy to jump power it.


If you suspect that the car is producing spark but not squirting fuel you can start the car and idle it on starting fluid or brake cleaner to test this theory.

-relays not grounding out (ie, the load is not unloading, and ground wires at the relays are getting power)
-DME not getting power at pin 15 of DME connector

Does the engine crank?

Engine Harness takes the the power to the DME;
Engine harness and DME directly ground to the engine.

Why do you have power on the ground side of the bundle at the relays?

12+ voltage @ the brown ground wires @ relays would be the #1 problem; fix this and your car will likely run

[e30rapidic]

is the ecu itself grounded? Also the ground strap from the oil pan to chassis in place?

[e30austin]

It's not the DME. The only thing I can think of is some sort of a grounding issue. Literally don't know what else it could be.

[Roysneon]

Still should make the IAC buzz if it was a bad DME. I had a bad DME when I first swapped my car and I'm pretty sure it still worked.