FIXED! Fuel+spark= No start??

[ykarabala]

Hello all,

I have an 86 325es with a rebuilt(top and bottom refreshed) S50 motor and Bosch 413 red label DME w a Miller War Chip installed. Engine is mated w a ZF320 transmission. I'm almost certain that I have everything installed correctly in terms of wiring. Using the e30 wiring for the starter and fuse box. Im using a wiring harness adapter that I bought from someone so I don't have trouble w the wiring. Deleted ABS as I'm using the Chase Bays set up (no brake booster).

Anyways, I go to start the car and it doesn't crank at all. New battery installed. New crank and cam position sensors as well. I've been thinking maybe I have the starter wired wrong, but I have 4 wires going to it- thick black from e30 for power, a power wire from starter to alternator (same post) and 2 smaller black wires that go to two different posts. Does this sound right? Anything else I should check?

When I turn the key, the fuel pump does NOT prime. I do hear the ICV hum but that's about it. W a test light, I can get it to work but that's about it. Sorry for the long post, but just tryna include everything.


Thank you!

[raj]

Your starter wiring sounds correct.
Triple check your engine grounds. Without a very good main engine ground, you won't get any crank. (To rule this out you can just use a jumper cable from the engine lift bracket to the strut tower. I had a similar problem and thought my ground was good, but it wasn't.)
You won't hear the pump when you turn the key because E30s do not prime the pump (at least in my 87, the pump does not prime).

[ykarabala]

https://goo.gl/photos/1gi1rQ9uCAd221e96

OK! So that was part of the problem!! Car cranks, but no start at this point!

[raj]

Please provide some more info: do you have spark? Fuel? It is common to get the fuel lines backwards, so that is another thing to check.

[ykarabala]

Spark is present. Fuel lines are correct. I did notice that fuel was going to the fuel pressure regulator, but when I slowly removed the return hose at the front of the motor, nothing came out. Right before the fpr is another small fuel hose (fuel-in line) and fuel was present there So I'm certain that my fpr is bad. Sound reasonable?

[Dave V]

You should get the thing cranking before you go changing stuff like the pressure regulator. I would advise checking all of your wiring with a multimeter, maybe when turning the key check if all starter wires are doing what they are supposed to be doing.

[bradmer]

I was in this same scenario six months ago. I didn't have an E36 fuel pressure regulator installed along the fuel line, it fired right up after installing one. That, and I had the fuel lines crossed.
When I tested, I found I had pressure from the tank all the way up to the fuel rail, but none in the fuel rail prior to installing the FPR.
Dumb question, is yours the E36 fuel pressure regulator?

[ykarabala]

Update

1. So it started to crank after raj suggested I jumper the engine ground. Thank you for that.

2. For fuel lines... I thought the fuel in goes to the fpr and that's why no fuel was at the front of the motor. My friend told me it was the other way around so I swapped the hoses and now I'm getting fuel at the injectors.

3. To get fuel, however, I have to jump the relay cuz I don't hear the fuel pump at all. So I'm thinking relay is faulty. What you think?

4. Even w the fuel and spark, still getting no start. Any other ideas? At this point I have no clue what to check. Anyone in the Central Valley down to check it out lol

Yes, e36 fpr b/c it's an S50 motor

[M3PO]

In terms of fuel, it sounds like it's either the relay or the DME/chip. Do you have access to a run of the mill 413 red label? A good red label DME should clear up any doubts about your DME and/or tune. Even with the fuel pump running, the DME may not be triggering the fuel pump relay and/or firing the injectors.

Is your injector harness ground hooked up?

[ykarabala]

I can get access to another unmolested 413 red label so I guess I'll try that. Yes, the injector ground is hooked onto the engine bracket. Thanks for the suggestion!

[bradmer]

the DME may not be triggering the fuel pump relay and/or firing the injectors.

This, I found in my notes that I had to wire in a fuel pump relay for the fuel pump to pressurize the fuel rail.

[e30austin]

I say you've got a DME issue. Change it out and see what happens. It will fire on a stock M50 tune, but I wouldn't run it for very long.

Did you have the front crank pulley off? If so, you may have it orientated incorrectly...which would cause crank/no start.

[AndrewBird]

If you have to jump the fuel pump relay, you don't have fuel. Check the ready and major sure it is working and also check for signal to the relay from the dme.

[ykarabala]

I put in my stock chip back and still getting same results. Gonna put in another fuel relay and main relay and see what happens.

[M3PO]

If you jump the pump relay and it still doesn't have fuel, the DME isn't firing the injectors. So I don't think that the fuel relay will help you any. It appears that the main relay works otherwise I don't think you'd hear the ICV.

Use a screwdriver as a stethoscope to see if the DME is firing the injectors during cranking.