No spark/ pulse at coil


#1

So I just got my e30 back from a shop. Spend 2400 bucks for them to put in a new engine harness, ECM, and select sensors trying to fix a no start issue. Coil doesn’t spark. They tested cps and all the stuff that I’ve been told to test in the past. Anyway still nothing. The headlights are off. Any way that causes a no spark at the coil? That’s the only thing I can think of at this point. Lol not to sure what to do. The shop basically said sorry but they are out of ideas. It’s a bmw shop in plano tx. Any ideas are welcomed! Lol


#2

I’m assuming they replaced the coil?


#3

did you replace the Cap, rotor, wires, impulse sensor, and the White fuel injection relay?


#4

And spark plugs


#5

What does the crankshaft position sensor look like? If its plastic where the Allen bolt attaches-throw it over your shoulder and find a metal based unit. Make sure its plugged into the correct connector on the harness under diagnostic plug(can be swapped with cylinder ID sensor on harness and will not start.) If that is correct and harmonic reluctor wheel is on correct(check if tdc is correct in timing cover) then test light on negative side of coil should pulse when cranking engine. Starter draw can make it appear to pulse,but should be definitely light/no light. If pulse exists,wire from coil should be pulled from distributor cap and spark test to ground when cranking(careful,spark looks for easiest path). If no spark and everything tests good,could be fusible link in positive small wire in trunk,key switch,or ground issues. I could diag quicker than typing this. Good luck.


#6

If everything else fails and you’re willing to tow it 3 hrs to Austin, Terry Sayther is one of the best.


#7

Tested all


#8

A bad plug will not cause the coil noy to pulse.


#9

I will keep in mind as a last resort.


#10

Thew swapped it out with a new one for trsting.


#11

Distributor cap or rotor? It’s after the coil but who knows.


#12

Check for power at DME. I think it’s pin 27. Little green wire. I had this problem recently while messing with wiring.


#13

I would not put stock in what “they tested”. If “they” were competent,it would be fixed. An e30 m20 setup is very basic. I am not trying to bash the mechanic(s) u chose,but some aren’t old enough to fix cars that don’t have scanner diagnosis.