Subject: 528E Engine turns over fine but no spark, no start Author: ptb123 : member since May, 2008 : 2 posts Posted on: 2011-02-01 22:31:20

My E28 528e (VIN 9712191, produced 01/87) cranks but won't start---I don't want to tow to a shop; please help with further diagnostics.

Friend removed A/C compressor and its lines. In doing, broke top radiator hose; coolant poured out onto engine, including distributor cap. Car would then not start. Has now been about 3 months outside in driveway without use. Over that time, the following tests have been performed:

1. Main relay coil was tested as open. Replaced with new relay
2. Spark check with an external resistor plug was negative in daylight
3. Fuel flow check with loosened line while cranking was positive. (not pressure tested)
4. Voltage checks w/digital VOM (input and output) Ignition SW in RUN Position and battery jumped to running car. Readings at 14.4 volts at line and load side of following fuses
Fuse #5 8A On board Computer and accessories
Fuse #6 8A Idle speed Control, Injection Electronics, On board Computer and accessories
Fuse #11 16A Active Check Control and accessories
Fuse # 12 8A On board Computer, Active Check Control and accessories
Fuse #1 16A Fuel delivery 0V but was 9.9V while cranking
Could smell gas at engine compartment after several cranking tests.
Coil + terminal with Ignition SW in Run Position was 12V. (14.4v when car was jumped.)
Coil resistance was 6300 ohms. (Spec is 6000 ohms) appears OK
Idle Speed solenoid valve supply was at 12v and the coil tested had continuity.
Coolant temp sensor at 50 deg F measured 33 ohms (spec is for 2100 to 2900 ohms at 68 deg)
Coolant temp switch measured 6.5 ohms to ground. (one terminal is at ground)
Ignition coil ground (at diagnostic connector pin 13) had 9.9v while cranking. Suggested that the speed sensor was working.
Opened Distributor and found it coated inside with oily sticky substance. Replaced cap and rotor.
After cap and rotor replacement, cranking sounded different, (some intermittent higher pitch) as if it was getting some ignition, but not enough to start. But spark test with plug #1 wire on external grounded plus did not show spark in daylight.

Any help would be most appreciated.

• 528E Engine turns over fine but no spark, no start - ptb123 2011-02-01 22:31:20 (609 views)
  • Can Speed, Reference sensors be cleaned, pics? - ptb123 2011-02-04 23:11:02 (586 views)
  • Re: 528E Engine turns over fine but no spark, no start - Area52 2011-02-02 22:48:07 (611 views)