QuestionHello Josh, I have a re-occuring starting issue with my 1988 BMW 325is. I have replaced the plugs, wires, charcoal canister, and air idler valve, and the problem still remains. When starting cold, it has a 50-50 shot of starting after the second or third revolution of the flywheel and idles and runs fine. Otherwise I must crank and crank and crank for about 15 second before it barely starts to run, and it idles like it is running on 5 of the six cylinders until it warms up for several minutes. I love the car, but I am too embarrassed to drive it. Any thoughts?
-Jeremy Grumbein
AnswerJeremy,
This is a pretty broad problem, with many possible answers. I would do some diagnostics to narrow down the list. First I would Check fuel pressure, should be in the neighborhood of 35-40psi @ idle. If you rev the engine you should notice the PSI going up to 45-50psi. If fuel pressure checks out, you should check the injectors and make sure they aren't plugged up. Injectors have tiny outlets for fuel to spray out, and any dirt or grit in your gas tank can be pumped to the injectors and clogging the outlets. Fuel needs to be misted into the cylinders for better combustion, if you have a port clogged it will let a "stream" of gas flow in, and it's harder to ignite, especially cold.
Check your compression, Being a 1988 I'm guessing it has 150k+ miles, so it wouldnt hurt to borrow/buy a compression test kit and test each cylinder. I think Autozone has them, just put down the deposit and you'll get it back when you return the tool(s) you have borrowed.
I would do an overall inspection to make sure nothing is out of the ordinary. You said you replaced the plugs and plug wires, but what about the distributor cap and rotor? The Coil and coil wire is another place to have problems.
Just go through and make sure everything is working correctly, to narrow down whether it's a fuel or ignition problem.
Hope this helps,
Josh
