S50B30US: no injector pulse

[austin8753]

hey there, guys. have an S50B30US, installed in an e30 chassis, that's having some issues... cross posted my issue over from r3v, in hopes that someone might be able to offer a suggestion i've overlooked. this one truly has me puzzled.

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11/85 325e with S50B30US conversion

car came in with a laundry list of issues, namely, a generally hacked together conversion and an unsightly wiring job. i tidied everything up (dressed the harness up with friction tape, deleted the automatic portion of the harness, installed the e30m3 wiring covers), eliminated the wiring harness adapter (cut/soldered a C101 connector in place of the X20 connector on the engine harness), removed the intake manifold to change the fuel hoses and coolant hoses, and reinstalled everything.

went to go fire the engine and had nothing. had a verified ICV hum, but the CPS tested at almost 1000 ohms (spec is 10% of 565 ohms), and was an aftermarket piece of crap, so i bought a new OE unit from the dealer. still nothing. the fuel pump primes while cranking, so i removed the injector harness cover and found they had 12v, but no switched ground.

the car will fire up on starting fluid, but the injectors are not pulsing. i've never, ever, had spark but no fuel. always been double or nothing. i've torn my hair out all day trying to figure out what the hell is going on... nothing.

i've confirmed the following:
-verified good tach signal at the cluster, tested pins 16 and 43 at the x6000 for + and - signal, verified, new CPS tests at 559ohms, so i think the crank signal is fine
-verified 12v at all red power leads at both main DME and fuel pump relays
-verified 12v at both sides of the injector
-verified 12v at the coil packs
-verified ground at pins 6, 15, 28, 34, and 55 at the x6000, as well as the engine harness termination
-battery distribution block has 12v at the fuseable link and at the battery terminal
-installed known, good working 413 red label DME

welcoming educated suggestions. thanks, guys.

[austin8753]

for fun, i installed a known good, working, camshaft position sensor, out of my personal, retired daily driver, e30 w/ s50 - made no difference.

[Eric93se]

Yeah I would have said cam sensor. So I think you should verify correct fuel pressure with a gauge.

- - - Updated - - -

How are you testing injector pulse?

Does the S50 require and EWS alignment?

[Eric93se]

Let us know if you get it going and post some pics of the car and swap! We would like to see

[samy01]

If the DME isn't seeing the crank or cam turning it won't activate the injectors.

-Bad crankshaft or camshaft sensor or both
-Bad wiring between crankshaft or camshaft sensor connector to DME connector (continuity test)
-Bad DME

I'd use computers to diagnose a computer controlled engine. INPA and a good scanner can show many individual signals and let you see what the DME sees. And it looks like it's not seeing something it should.

cut/soldered a C101 connector in place of the X20 connector

Why?

I don't have the part in front of me so I could be wrong:

Years ago in another forum someone reported his car wouldn't start with the cap removed from the round diagnostic port. It wasn't clear if this was a problem or the way it should be. If I remember correctly there's connectors in the cap, so the cap probably does something. I assume you don't have a cap on your C101 that does the same as the OE cap did.

[Eric93se]

Samy if you read his post you will see what he did with cam/crank/dme.

Regarding the C101 and x20, there may be some changes in wiring that got people with a no start issue:
https://www.r3vlimited.com/board/for...adapter?page=1

[samy01]

yeah and i don't see him continuity testing the wires, do you?

[austin8753]

If the DME isn't seeing the crank or cam turning it won't activate the injectors.

-Bad crankshaft or camshaft sensor or both
-Bad wiring between crankshaft or camshaft sensor connector to DME connector (continuity test)
-Bad DME

I'd use computers to diagnose a computer controlled engine. INPA and a good scanner can show many individual signals and let you see what the DME sees. And it looks like it's not seeing something it should.


Why?

I don't have the part in front of me so I could be wrong:

Years ago in another forum someone reported his car wouldn't start with the cap removed from the round diagnostic port. It wasn't clear if this was a problem or the way it should be. If I remember correctly there's connectors in the cap, so the cap probably does something. I assume you don't have a cap on your C101 that does the same as the OE cap did.

crank sensor is a new, OE unit, and tests out right within spec.
camshaft sensor is a used, but good, OE unit, and tests out right within spec.
continuity between camshaft and crankshaft sensors, and the engine controller, tests out just fine.
DME has also been pulled from my retired daily driver, no change.

c101 gets cut and soldered for a seamless install in an e30 chassis without an ugly, bulky wiring adapter. i am not talking about the diagnostic connector.