I am a new member, an old guy. I do not profess to be a great mechanic but have always been successful fixing my cars with time patience and some sound advice. My son bought a real nice 633Csi 65k miles that will not start. He is young and impetuous so I have been asked to get it to run while he is away at school. We have the famous power to coil but no spark to distributor. I do have injector pulse. I have checked all the on line advice. I have ruled out the ignition switch, fuses, main relay & coil and all check out OK. I replaced the speed & ref sensors because the plugs were bad and have verified that they are in the right locations. We purchased replacement OBC (old style) and ECM and neither worked. I tried to do the 15 minute countdown with the OBC to check if a security code was entered. When I reconnect the battery and turn the key to pos 1 I get the four dashes and no 15 minute countdown so I assume there is no security code. I hope you guys can help me out I am dead in the water.
My '84 633 started acting wonky. Sometimes it would fire up immediately, sometimes it would spin a lot and finally fire up, and sometimes it would just spin forever with no firing at all. It would get progressively worse. Crank fine this time, long crank the next time, and no crank the third or fourth time. When it would do that (no crank) the OBC would be flashing, asking for a "code". I'd disconnect the battery for 15-ish minutes, reconnect it, and it was back to firing up right away. After putting up with this for a week or so, and being stranded twice (once in front of the auto parts store!) I'd had enough. Some on-line searching turned up several people that had experienced the same problem, and the cure, other than replacing the OBC computer, was to bypass the security system. It' super simple. A jumper between the #14 and #15 pins on the black connector plug on the OBC computer (it's under the instrument cluster, above the knee bolster) and I've had no more problems. The jumper takes the OBC disable relay out of the circuit, nothing more. Central locking still works, all the other functions of the OBC still work.
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