85 325es won't run

[madcowbreeder]

hello everyone. Ok. I have tried, time to get some help. She will run occasionally. When she does run, it backfires repeatedly from 1200 to 2400 rpms straightens out but struggles to stay up in the rpms. When driven now she can't rev over 3000 in gear, starts to break up. But now, she won't even bump over. If I crank and crank and crank she will pop a little bit.

When I bought her, the following has been replaced

Fuel pumps, tps sensor, fusable link for fuel pumps, fuel lines, fuel filter, all relays and fuses (except main and I don't know where it is), ECM (I guess the larger one??) plugs, wires, cap and rotor, air filter, ICV, and thats about it.

When I first picked it up, I had it running just by cleaning the relays and putting it all back together. That lasted a week.

It has excellent spark, especially when someone cranks it before you can get your hand off the screwdriver in the plug wire. I cut the cat out because the original owner said that it was plugged up, didn't help.

I was also told the cold start injector was bad but I removed the fuel line and sensor plug and still no fire.

Another possible problem is the vacuum line that goes to the fuel pressure regulator on the fuel rail, when unplugged doesn't make a sucking noise and no pressure when I put my thumb over the hose, I disconnected it from the manifold and still no vacuum pressure (out the manifold).

This is kinda why I hate other people's projects. Any help anyone can give would be greatly appreciated.

Thanks

[darkhorse737]

CHECK TIMING.... i know it is not adjustable, but the timing should read 8 degrees BTDC with vacuum hoses disconnected.

if you don't achieve that mark, then one of the sensors that provide timing info to the DME/ECU is faulty

If it won't run, check firing order; check crankshaft sensor; and the #6 cylinder reference sensor.

** for your own peace of mind(since it is another's project).. i suggest you check the plugs. They may not be the correct spec for your car. Redo the cap and rotor +wires.

** make sure the connector to the AFM is snug.

**main relay, fuel pump relay, and 02 sensor relay are side-by-side mounted in a plastic box by the left-side shock tower.

[madcowbreeder]

hey, sorry about the delay. TS Fay messed me up pretty good. Luckily I built my garage up, but it is still about 3 feet of water seperating me from my cars!

The waters are coming down so I will get back to playing with the bimmer soon and I will let you know what I find. I did however notice when I was putting things up I was in the car with a flashlight, that the electronic mpg and timer thing flashes ----UDP I never noticed this before, I thought the thing didn't work, I guess just the back light is burnt out. Is this an alarm thing that I have read elsewhere or nothing? I will check it out on a few strings, thanks for you advice again.

I will let you know

[madcowbreeder]

ok. So I was working on the car today and I think I have it narrowed down to just the main relay. when I pull it out and clean up the female contacts it will bump over, sometimes even run for a minute and then shut off..If I pull the relay and reclean it it will again bump or start...I have found another main relay in the car, but it is a metal one and has different numberings on the underside. I think 30 and 87 are reversed. The main relay in it right now is a plastic one which matches the others. I tried the metal one, nothing happens. I am going to assume it is either dead or the wrong one. I think I will also check the wires themselves as there may be a short.

My fear is that the relay is fine but something else is killing it. It wants to run her heart out, but something is blocking her. Is there a diagram of all the sensors and how to test them one by one? I have a garbage bag I found under the spare tire of tons of sensors and relays, some brand new. I would plug and play but I think testing and saving my bag of spares would be wiser.

Thanks

[madcowbreeder]

ok.. just logging things as I go for my own record...

I had her running for about half an hour. Breaking up bad like it was before at around 2000 rpm. The cat is cut off for now, I took the cold start injector out and it is working properly it look like so I am confused. I did undo the fuel pump from the undercarriage and have it free hanging and it is working like it used to. I imagine there must be something wrong when I hang it. I haven't checked fuel pressure yet. It seems like it is flooding out though. I did pinch off the return line after the fuel pressure regulator and the backed up pressure caused the cold start injector to spray continuously. I didn't check to see if it did it with the power disconnected from it. Perhaps if I do that will tell me it is flooding... Maybe a bad fuel pressure regulator or CSI and the other injectors stuck open? I guess I will have to pull a plug and see what it says..

If anyone has any ideas, let me know77

hmmm.. When I am blocking off the return line, there is nothing really there to tell the pumps to stop pumping so maybe they should blow through the injectors? Might be a good sign