Firstfives.org

Hi Everyone, It's my first post but have found so much useful info on this site, I'm loving it. Ok here goes. I bought a 1980 528i been sitting for 4 years, had a bad fuel pump and a bad clutch, and some field mice decided some of the wiring tasted good so they ate some of it, as well as the clutch pressure hose?! So I've replaced the fuel pump, clutch, rewired eaten wires, and now I'm in a no start situation. I have fuel to the rail, and spark and it will run if I put a bit of starting fluid in the air box. The spark plugs are not wet after cranking it for a while. The seemingly last thing I can think it may be would be plugged injectors. Does this sound like the next thing for me to check and has this happened to anyone before with a sitting car? Thanks in advance for any help you may be able to give me or direction you may be able to point me in !!

ok if you are getting spark and gas and but the does not start unless you spray carb cleaner in the air box that means you are not getting power to the injectors you need to check the combo relay is the double relay by the driver side and the injector ground cable is in the glove compartment a single wire with a square cover that comes out the engine harness by the ecu needs to be connected or injectors wont work. It happen to me once I was doing some work in the glove compartment I disconnected the cable by accident wile the car was on I turn off the car then It would not start i would have gas and spark but it would not start it would only start when i spray staring fluid me going crazy i found the wire disconnected by ecu connected and it stared right away

I will check both of those possibilities but I did take one of the injector wires off and was getting a flash on my test light, so I'm thinking that is not the problem. But I will check as it certainly sounds better than taking out the injectors! Thanks for your reply!!!

It is possible that the injectors have a permanent 12V, and the ECU pulls the other wire to ground if it wants to inject fuel. Motronic 1.3 functions that way, at least. So a test light will give you half the information - you have 12V on them.

I see one wire coming off of the harness that goes to the ECU, it is a gray wire and then connects to some kind of rectangular connection that goes to a ground somewhere over radio, I can't really see where it goes but it does show continuity to ground./ Is this what you were speaking of? If so it was connected. Any other ideas? Anyone?

Ok, so where are all the helpers? After reading so many posts where people were so helpful, I am kind of shocked at the minimal help I've been receiving on my, what seems like should be a small, problem here. I went and got the injector test lights at autozone today and I'm not getting any light at all, But if I use a test light I'm getting power from both wires that go to the injector. I'm starting to get upset at this problem and am thinking of parting the car out as many before me have done. Can't afford to take to professional mechanic and not getting much help on this forum. Been working on this for over a week and just about had it. Please help!!! <sniff>

Do you know if your combo relay is working properly? If you can't get the fuel pump to run by manualy opening the AFM door with the key on as described below or hear an audible click at the combo relay it most likely a faulty combo relay.

Here is a post that should help from John about fuel delivery.

quote="John in Simi Valley"]Karl, you can test the flow of fuel from the fuel line that goes into the rail.
The source hose is supposed to be the line that goes along the firewall and enters the rail approximately over the cylinder number 6.

Unclamp that fuel hose and stick it in a clear container that will capture some gas. If you turn the ignition switch to "ON" position (but don't crank the motor) you can momentarily toggel on the fuel pump and seeing if fuel is coming out where it's supposed to.

To power the fuel pump, the throttle body has some micro-switches that contact when the buttlerfly valve opens slightly. So if you manually articulate the throttle linkage and contact the micro-switch, the fuel pump should do it's thing.

Of coarse, a fuel pressure gage would be a great check too. They're cheap and simple.[/quote]

Took it apart, heated up all the solder connections, when I open the AFM door the fuel pump pumps fuel. I think I read posts that said this was what confirmed it was working properly, but not sure as I have read about a thousand posts trying to get this car to run.....Thanks for your help though I do truly appreciate it!!

I added a quote from John to my post. I would move to fuel pressure if the combo relay is working. I was looking at some in line fuel pressure gauges today for my car many for less than $30. It seems unlikely all the injectors would be clogged at one time. I would look at fuel delivery and grounds as mentioned before. Jeff

Got fuel pressure, the noid light doesn't light up when trying to start car

I have a factory manual that covers some tests for the injectors. It is for my car a 1977 530I I will post if you think it may be helpful. Jeff

that would be great Jeff, and thanks!!!!!

I posted 16 pages on fuel delivery from my manual to photo bucket. You can find it here. http://s295.photobucket.com/albums/mm13 ... rywdennis/

Remember my car is an earlier version than yours but the system tests should apply to both in most cases.

It may be that others here have your exact factory manual but the books can be hard to come by.

I'm going to be working on mine this weekend and have both an E12 and E30 that have decided to be difficult this spring. I need to add fuel pressure gauges to both. If I get frustrated I can yank all the injection off and run a carb set up I have.

Good luck, Jeff

Soundkat wrote:Hi Everyone, It's my first post but have found so much useful info on this site, I'm loving it. Ok here goes. I bought a 1980 528i been sitting for 4 years, had a bad fuel pump and a bad clutch, and some field mice decided some of the wiring tasted good so they ate some of it, as well as the clutch pressure hose?! So I've replaced the fuel pump, clutch, rewired eaten wires, and now I'm in a no start situation. I have fuel to the rail, and spark and it will run if I put a bit of starting fluid in the air box. The spark plugs are not wet after cranking it for a while. The seemingly last thing I can think it may be would be plugged injectors. Does this sound like the next thing for me to check and has this happened to anyone before with a sitting car? Thanks in advance for any help you may be able to give me or direction you may be able to point me in !!

The injectors are stuck shut.
If you have another old car, I have a crazy idea for getting them freed. But you'll need an ignition signal to trigger the ecu.

I use the coil negative terminal from another running car. If you have that, let me know and I'll post the details.

I have 2 69 Dodge Chargers? Not sure if that would work, but I'm not getting a light out of the noid injector pulse tester light, so even if they are stuck shut, and they became open or operational, there is no pulse to trigger them. I am working all weekend so haven't had time to mess with it, but I did get to down load the pages put on photobucket!!! Thanks for those!!