I've got a 1987 BMW 535i that has some kind of ignition problem.
There is no spark at the plugs.
I've replaced the ignition coil, distributor cap, rotor, wires, plugs etc.
and still cannot get a spark at any of the plugs.
I'm thinking Ignition switch or Ignition Relay to be replaced next, however,
I'm no mechanic.
Anyone with thoughts on this would be greatly appreciated.
Looks like you've been flailing along quite nicely (flailing = waving
arms and throwing parts at the car in the hope that this will fix it.
Eventually - if you replace the entire car - it will, and of course the
last thing you replace will be the problem component.)
The ignition relay is certainly a failure point - and not horribly
expensive to replace if you're going to flail. I'd prefer to check the
output of it with a voltmeter before spending the money, but if
diagnostics aren't your thing and your wallet is deep.. go for it.
The ignition switch is an unlikely point of failure IMHO.
I also experienced a failure of the Motronic in my old '87. They have a
failure that isn't uncommon of the solder joints in them that eventually
failing due to heat cycling. It's usually one of the output transistor
joints. A used one off a wreck fixed mine, then I disassembled and
resoldered ALL the joints in the old Motronic - and tried it in the car.
It worked fine after this.
If you loose all spark - it is very unlikely to be plugs, or plug
wires, or cap. These might cause loss of spark at one or more plugs -
but not all 6. Total loss could be rotor, might be coil - but all of
these are simple to check with an inductive timing light (or a simple
neon ignition tester) - saving you a whole bunch'a money.. but like I
said, if diagnostics aren't your thing - dig deep and often, the
dealer's parts department will become your friend.
When I connect a voltmeter to terminal 15 of the ignition coil (and ground),
I'm only getting a reading of 6 to 7 volts when cranking the engine.
Should I not be getting a fully 12 to 13 volts to the Coil when cranking the
Any comments would be appreciated.
Voltage at the coil is a flaky issue. Mine reads in the same range
as yours but runs fine... Check the sensor and get back to us with the
result and we'll go from there. The engine is controlled by the ECU
and most likely it's missing a critical input signal and therefore the
engine will not run.
Hurray! Found the problem.
I started fooling around with the Reference and Speed Sensor wires to see if
I could see any chafing or other damage. It was not readily apparent,
however, just for the hell of it I tried starting the beast and unbelievably
she roared to life.
One of those sensors is flaky so I guess I'll replace it. Just got to find
out which one it is.
Thanks to everyone who assisted.
On my 325, this is known as the crankshaft position sensor and it
will effectively remove all incentive for the motor to run. Mine had a
broken wire at the potting compound and as long as the wires were
still touching it ran but if you hit a bump in the road and the wire
moved it would quit.Find this little sucker on yours and throw a meter
on the connector, if it shows continuity, look elsewhere. If it
doeesn't, replace it and I'll bet the car runs once again...
Hey I seem to have the same problem. I finaly found the crankshaft
position sensor and unplugged it and it starts up..but my car still
wont start if I leave it plugged in...try it out ..it seems at least
youre getting some response and help here so im also keeping trak of
your page..It seems you have a bit older car so maybe its not the same
issue..I think your car actualy does have a cold start injector while
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