Helping my son with a 530i which will not start after replacing the bad engine with a used one, but without guaranteed history on the replacement.
Car cranks fine, compression OK on all cylinders, new plugs which fire, fuel pump running. Went through the various inputs to the DME and all inputs seem reasonable, although without firm specs on each, having to "deduce" on some.
Lab scope shows what may be the problem. Crank sensor, cam sensor and ignition waveforms are "right on" . However the injection pulse seems to be 180 degrees out of synch. The scope shows the injector pulsing immediately before the spark plug fires, but that would be with the valves closed on the compression stroke. The injector should be pulsing at the end of the exhaust stroke so the fuel is pulled into the cylinder on the intake stroke.
Doing a lot of searching and reading trying to find what causes the DME to set the injection pulse timing in case something "feeding" the DME is causing the problem, but have not found anything yet. Have the feeling that it will be something simple that I/we missed, but needing the insight and wisdom of those with more experience in the area than myself.
Suggestions? Reference links that provide detail information?