M50 no spark or fuel.

[PeakFab]

Hey, I'm trying to get some help on my e34 m50 swap into my 91 e30 318is. Using a 91 m50nv with a white label 402dme e34 auto harness.

I have a no spark and no fuel issue but I can crank the engine. so far I've checked:
DME pin:
26 constant 12v
54 constant 12v(I think this is suppose to be swtiched though?)
56 switched 12v
65 switched 12v(for the e34 auto harness)

55 grounded
6 grounded
34 grounded

I have checked Crank Sensor at 522ohms at pins 67 + 68
I have been able to jump the fuel pump and it works
I have 12v at the injectors.

Something I noticed that is weird is there is constant 12v at the MAF.

I have a new CPS on order, but in the mean time is there anything else I can look at it?

Does it have to be a red or silve 402 ecu? or does it not matter on a 402.

[e30austin]

A 402, 403 and 405 will run your NV motor. Color doesn't matter.

Is your DME properly secured to the chassis? How about the ground strap at the coil packs, as well as the engine arm to frame rail?

Is your power distribution connected correctly?

Does your ICV hum, with the key on? That will tell you if you have an issue with the CPS.

[PeakFab]

Good to know about the DME. I was worried I'd have to buy another one.

The fuse box has a cable that splits at the end both ends are bolted to the fusable link/12v battery block.

The DME is currently just sitting on the fender I heard it doesn't have to be grounded or anything.

The ground is on from the chassis to the passenger motor arm.(stock m42 ground) the coil packs are grounded aswell. I even checked the ground near the Injector rail.

Does the 12v constant at the maf sound weird?

[pazi88]

Yes constant 12v supply to MAF. Most common no start issue for m5onv swaps is that the crank and cam sensors are plugged to each others connectors. Try swapping cam and crank sensors and try again. The connectors in harness are identical so it's easy to mix those.

[PeakFab]

I thought that at first aswell, so I checked the resistance(ohms) at pin67 + 68 on the DME.

Sorry but I don't understand. Yes there's suppose to be 12v constant, or yes it's weird that it's 12v constant.

[e30austin]

One of the pins will have a constant 12v. I wouldn't get hung up on that. Pazi is correct, I would make sure your crank and cam sensors didn't get swapped, somehow. I'm sure it's something very simple. I would make sure all your engine wiring connectors at the distribution block are connected correctly (not just the ones at the fusebox side).

Maybe posting a few pictures of your setup would help someone to see a possible irregularity.

[pazi88]

I thought that at first aswell, so I checked the resistance(ohms) at pin67 + 68 on the DME.

Sorry but I don't understand. Yes there's suppose to be 12v constant, or yes it's weird that it's 12v constant.

But you didn't try swapping the cam and crank sensor plugs? The sensors are same type so measuring resistance tells nothing. Trying those another way around doesn't hurt the ecu.

+12v is to power the maf sensor

[PeakFab]

So I double checked the crank sensor connector by checking continuity from pin 67 at the DME to the connector. Its correct.

I've heard people say before that the OHM reading on a crank sensor can be correct and still be non-functional, a new one should be here in a day or 2.

Here 2 pictures of power block.

[PeakFab]

The new crank sensor has arrived and installed... Still no spark or fuel. Even double checked the connectors are going to the right sensor by checking continuity from pins 67 to crank connector, and pin 44 to cam connector.

I also followed this to make a patch harness:

[PeakFab]

So Maybe its the ecu? I do not have any check engine light on the dash, or tach movement while cranking. I dont have a car to test my ecu on, is there a way I can test it with a multimeter?

[e30austin]

Again, does your ICV hum, when the key is turned to the "on" position? That will give you an indication of a good DME, proper battery connections at the dist. block, and good crank signal. If one of those is bad/improper, the ICV will not hum.

[PeakFab]

Well the problem with that is I don't currently have the right ICV for the car. I have a 2 prong ICV(mistakenly bought it) and the harness is for a 3 prong ICV(which I still need to find). But that shouldn't stop the car from getting fuel or spark.

[cocofunk]

But the humming is an amazing indicator of ECU health and signal. ICV may not deter your car from starting, but no ICV deters you from getting that hum that Austin is talking about - hence a good diagnostic sign of ECU, signal, etc.

[Garageaholic]

The MAF has constant power. but no spark and fuel. that is weird.

You sure you have the correct SPST NO relay installed?
Your fuel lines are not crossed?
Your Engine Ground is connected to chassis with no more than 3 ohms of resistance?

[PeakFab]

So update on the situation. It was the ECU. A friend had a spare red label 402. Put the ECU in and the car started first crank. I'm not sure if it is a EWS issue or something else with the silver label 402.