My First No Start Thread!!!

[kroberts]

Well I completed the last connection. My engine is in and finished.

It wont start, but it's in.

That's ok really, I didn't expect it to fire up first time. This project has kicked my ass from day one.

I finished up and checked all my connections one last time. When I hooked up the battery, I heard a funky hum. The key was in my hand and the ICV was getting power. SHIT. When I turned the key to start the car, the ICV quit. My fuel pump isn't running either. Fuses are all good.

This sounds like a relay problem right? (I hope it's that simple). I forgot to stop at the dealership today after work to buy new relays so I dug through my parts box for some 5 and 4 pin relays. Is there such a thing as a normally closed 5-pin relay? Why would it open when I turn the key to start?

The schematic in the E36 Bentley refers to the Engine Control Module Relay, is this also called the main relay?

If I'm reading the schematic correctly, the ECM relay gets straight battery power to pins 6 and 8 right? Fuel pump relay pin 6 should be hot all the time too right?

Schematics hurt my brain.

Shit shit shit.

[PiercedE30]

What motor? I've found that the E36's use two different style main relays, both have the switches on different pins. Check the relay plug and make sure the relay matches up with the config of the relay plug (ie switched control on the outsides and the three power wires in the middle).

[kroberts]

Engine is an S52

I hope it's just a relay issue. I fucking hate electrical work.

[PiercedE30]

The funky hum that you are hearing is the power back feeding into the relay causing it to hum. Plug the relay in and put the batery on and listen to the relay. More than likely your SI lights are going to be flashing too, or at least in my case they did. The switched wires on the relay plug (that control it) are going to be the small thin wires. Check on the relay for where pin 85 and 86 are in relation to those small wires. If they aren't in the same spots, get a different relay and try and match it up.

[kroberts]

It was definitely the ICV humming. They're supposed to hum a little aren't they? The one on my M20 did.

I have a Treehouse adapter. If I hooked up one of the wires incorrectly (tach, road speed, fuel rate), could that cause a no-start condition?

Gotta go to work.

[BigD]

The ICV is buried pretty deep on these engines. I can't hear mine hum and it idles perfectly. Are you getting spark? How do you know your fuel pump doesn't run, did you test fuel pressure or measure the power at the connector? BTW probably a dumb question, does it crank?

[PiercedE30]

It really does sound more and more like you don't have the right style relay. Hell, on the E36's, there are like 3 different ones used in different year ranges. They all have a different location on the relay itself for the switch.

[kroberts]

The interior is out. I removed the pump cover to verify pump operation. Oh yeah it cranks nice.

I went to our local dealership today. What a waste of time. The parts counter there is famous for shitty service. I told the guy what I needed, he looked up relays on the ETK and said he needed a part number because the computer didn't list relays by application. I said I need the main, O2 sensor, and fuel pump relays for a 95 325i. He stood there. Douchebag.

I guess I'll use the pelican parts site as an ETK, I'll get better service.

[BigD]

How do you mean you verified the pump with the cover off? Like fuel pressure or power? Correct me if I'm wrong but until the engine starts, the fuel pump is not going to run at full bore.

[1990m3]

if the fuel pump works...do you have the fuel lines hooked up correctly?

[gazellebeigem3]

if the fuel pump works...do you have the fuel lines hooked up correctly?

haha, i switched mine! It took me about half a second to figure it out though, as i always manage to do it.

[kroberts]

The access cover under the back seat. I removed it. You can hear/feel the pump running (at least I could on my old 325). I thought I read somewhere that the pump kicks on when you turn the key on. If the pump waits for a signal that the car is running...and you cant get the car to start...how does the pump ever run?

Fuel lines
Silver-supply
Black-back

Hows about you guys go out in the garage and write down your relay part numbers for me. I found these part numbers on the Pelican site.

Main: 61-36-1-729-004

Fuel & O2: 61-36-1-378-238

I know those numbers wont be on the relay, but every little bit helps.

I didn't get to work on my car today. I spend Thursdays with my kids:). Tomorrow, hopefully, I'll get it started. If I do, I'll post a vid of it idling through open ebay headers.

[BigD]

If the pump waits for a signal that the car is running...and you cant get the car to start...how does the pump ever run?

My understanding is that it runs at low speed to just maintain pressure while the car starts, and once it does it kicks into full power. I know when the S38 on my M5 went south, everyone said go to the trunk, open the cover and listen for the pump buzz. I don't know if you guys have ears like a bat but I couldn't hear shit, but the fuel pump was fine. Same with my E30. When cranking I can't hear the pump. Driving around with the cover off, hell yeah (can hear the howl).

[kroberts]

It Runs!

It was just a relay problem. I bought the correct relays today and plugged them in. I primed the fuel system, buttoned everything up, turned the key, it started right up. Damn is it loud. Sounds good. My next concern will be making sure I've got the cooling system bled.

[Teaguer]

Congrats ! :up: