1983 BMW 733i

Tiny
RONALDO SANDERS
  • MEMBER
  • 1983 BMW 733I
1983 BMW 733i 6 cyl Front Wheel Drive Manual

car turns good but will shut off when I release the ignition
Saturday, May 22nd, 2010 AT 10:18 AM

1 Reply

Tiny
CARADIODOC
  • MECHANIC
  • 33,727 POSTS
Hi ronaldo sanders. Welcome to the forum. Suspect a defective ignition resistor going to the ignition coil or control box. It drops voltage to a safe level during driving, but during cranking, battery voltage will already be low, the resistor is bypassed to maintain a strong spark. When the resistor is open, there will be no spark so the engine won't run, but since it is bypassed during cranking, it does run as long as you hold the switch in the "run" position.

Chrysler had the same problem in the late '70s. It was so common, a lot of people carried a spare $3.00 resistor with them. In their case, the resistor was bypassed by a terminal on the ignition switch so you could shift to "drive" while holding the ignition switch and the engine would run. In gear, the neutral safety switch would turn the starter off. GM and Ford used a tap on the starter solenoid to bypass their resistors so you were stuck on the side of the road.

Caradiodoc
Was this
answer
helpful?
Yes
No
Saturday, May 22nd, 2010 AT 3:19 PM

Please login or register to post a reply.

Sponsored links