1984 911 will not fire

[timegs]

I recently drove my 1984 911 on a 120 mile round trip. It ran flawlessly. When I got a mile from home I stopped and filled the gas tank.I fired it up and drove home. The next morning I get in it to drive to work. She winds just fine,but will not fire a lick. My neighbor and I checked it out ....It has power coming to the coil,but isnt firing at all. I figured it just needed a coil,but he says a crank angle sensor... Please help....I dont want to just throw parts at it.....I might also mention,the day that I took a the trip it was raining. It may not matter just wanted to mention it....HELPPPP

[JTL]

Did you search the archives yet? There are a few threads on these kind of issues.

My -84 targa did this twice. Both times is was one of the two flywheel sensors. I started by checking for spark. There was one so I proceeded to check the dme inputs, one at a time. One of the flywheel sensors didn't produce the correct resistace value. I had the same problem both times, like I said. I recommend getting a Bentley manual. It has been essential for me with working on my 911.

Cheers, jt

[JTL]

Sorry - typo.

I meant to say there was no spark.

[ChkbookMechanic]

Flywheel sensors are something to check along with the DME relay under the seat.

[richemj]

There is an 84-89 Carrera No Start Diagnosis write up on the Technical Article side of this site that is really useful. Take a look over there.

No-Start Troubleshooting:
http://www.pelicanparts.com/techarticles/911_carrera_start_troubleshoot/911_carrera_start_troubleshoot.htm

DME Troublshooting:
http://www.pelicanparts.com/911/technical_specs/911_DME_troubleshoot.htm

[seafood10]

Second the sensors, I just went through the exact same issue. Make sure you have a good Digital Volt Meter and start testing the relays and sensors.

[seafood10]

BTW, if it is the sensors I picked up the less expensive BMW sensors from our host, let me know and I will dig out the part number.

[Hugh R]

My 84 did the same thing once, it turned out to be that I had an internally shorted fuel injector. TRE said they'd never seen that before. It completely wacked out the signals to/from the DME.