Here's the broken down:
I bought a '94 BMW 325i coupe that had been sitting for four years as a not starting car. So I have made it my mission to get it started and back on the road. It will crank all day long but it will not turn over. It has now got a new fuel pump, fuel filter, fuel pressure regulator, six shiny spark plugs and good fuel after syphoning all of the old sludge out. Not sure of the fuel pressure at rail but with fuel coming back through the return line via new fpr I assume it is sufficient. The engine starts and runs for a few seconds using CRC engine start then dies out (during this the tacho moves, so alright crank position sensor?), this is what made me think it would be a fuelling issue. It has a Uniden immobiliser and had been sitting with no battery, could this cause some sort of computer de-sync after four years leading to non-sparking spark plugs. I have used a test light at the injectors and while cranking it flickers on and off showing the injectors getting pulse, but I am yet to test them with an oscilloscope. This is the first BMW I have worked on and I am enjoying it, but it has been many months sitting in the driveway looking pretty but not doing a hell of a lot.
This is me calling for help. Please internet, enlighten me...
Pull the fuel injectors and test them. We have had some problems with an E32 750 which was parked for years. We changed fuel pumps, fuel filters, etc, starter turned the engine, but the engine did not start, only with starter spray it started briefly.
Then we pulled the fuel injectors and all were clogged up by gums of the bad fuel.
Gasoline degrades over time. That leads to a number of problems, ranging from hard starting, to rough running, to no starting at all. Hydrocarbons in the gas react with oxygen to produce new compounds that eventually change the chemical composition of the fuel. This leads to gum and varnish deposits in the fuel system. These deposits and impurities can clog up fuel lines and filters, as well the the fuel injectors.
Some of the fuel injectors we could get running again , others we had to replace.
People owning rv, boats, lawn equipment with carburators also know this problem, the carbs get clogged. That is why they use STA-BIL or similar for the fuel when they store the equipment. Otherwise the carbs can be very badly gummed up and clogged, too, and have to be torn apart and soaked in carb cleaner.
Shogun tricks and tips for the E32 series are HERE!
Test each coil pack for spark or if within spec. Check crank sensor to see if within spec. Remove the aftermarket security system as its a waste of space in 2018 and exists to deter car theifs in the 90s from stealing your highly advanced cd player. (Sarcasm) after that lock and unlock all your doors with your key and it should start. If not still, check the door lovk modules for working, check the dme for corrosion.
I am having the exact same symptoms: my car sat for two months, battery died in the process. Before that my car was completely reliable.
During this period of sitting, injectors were serviced. The tech who cleaned them said they were good and flowed the same amount after service.
I have a brand new battery now and can't start it (my thread started close to this one).
Could something inside the 20something year old computer (mine's a '95) die, discharge, reset, damage or something from a having a battery go flat while connected? After a lot of reading, I find this occurrence to be somewhat common...
Lock and unlock your doors... Dead batteries can engage the drive away protection.
Thanks Shogun, I will take the injectors out for a clean this weekend. I wouldn't be surprised if they are all gummed up with bad fuel residue as both the filter and the regulator were.
I'll have a poke around with the aftermarket security system and try running it without it Spydeg. I tested the crank position sensor a while ago and from what I remember it was within spec. I'm getting fuel from the return line back into the tank so the CPS must be working otherwise no power to fuel pump (correct me if I'm wrong). Haven't tried testing the plugs outside the engine, but since it would run with starter fluid I assumed they were alright (unless the starter fluid combusts under a bit of pressure to help start diesels). I'll do it anyway for some peace of mind.
Last edited by Momopl7; 11-11-2018 at 07:34 PM.
If it ran for a second on starter fluid then shogun is probably right, injectors or a massive vacuum leak.
Completely remove the aftermarket alarm.
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I pulled the fuel injectors this morning and cleaned them out with some carb cleaner. After pressurising them in reverse with the stuff, a brown sludge ejected out of the rail end. They were not opening or closing at all with voltage because they were caked with bad fuel gum and varnish. Now they work good as new and the car starts first try every time. So thank-you very much Shogun and others, I have been stuck on this for a very long time. Even though this is a short thread is has been extremely helpful and I will remember to come back and help others with what I have learnt over the past few months.
Once again shotgun is on top of it!
Alright new issue. The car does run but it will have to crank for a while before it starts, the fuel pump is not priming for the one or two seconds when the key is in the run position before it starts. Is this a model/year thing because the pump keeps pressure while the engine is running, but not before.
Have you tested fuel pressure? Changed fuel filter? Run some injector cleaner.
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Assuming its good is not good enough. Same thing happened in another thread, the pump was bad.
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