Help! Car won't start after DS2 Conversion!

[Anonymous]

Hey Guys,

Well I attempted to do the conversion today, but was stopped by a problem. I followed the DSII diagram with the MSD box from the tech section. The only modification I made was for the 12v source. With my original point-ignition system, there was a plug that came from the firewall and plugged into the positive side of the coil. There was no mention of this plug in the DS2 wiring, so I used it as the 12v source (which I tested with a multimeter.) Almost new plugs are gapped at about .45 and I used brand new HEI wires. When I go to start the car, it tries to turn over but only backfires through the carb. I tried to set the timing to 12 deg BTDC, but i'm not positive that it was definatley at 12. I'm going outside tommorow to try to get it started and wanted to run it by you guys in the hope that you could give me some ideas.

Thanks!
Mike

 

[CobraSix]

Check that wire you used from the firewall, it may be a resistor wire and may only get 8v at the end. Some cars had that wires as the ballast resistor, so I would check it for 12v. If it isn't, I'd find another 12v source or replace the wire with a non-resistor wire.

Slade

 

[Anonymous]

Checked the wire with a multimeter last night and it came out just over 12v.

 

[CobraSix]

I may be wrong, but backfiring through your carb sounds like you may be way out on your distributor or wires. That would be the only other thing I can think of.

Who did you set 12 BTDC?

Slade

 

[Anonymous]

After a lot of thinking last night, I think I might have figured out what I did wrong. Today i'm going to go out and check to see if spark #1 fires at TDC!! Kind of forgot to check that last night I'm hoping the 12v source isn't a problem and that my dizzy is just 180 deg out. Any other ideas for a 12v source incase the dizzy adjustment doesn't fix my problem?

Mike

 

[66200i6]

Incorrect timing causes backfires. I think you're on the right track.

Good luck, Ric.

 

[CobraSix]

Sounds more like a timing issue. if you get 12vs on the ignition wire, you should be fine.

Slade

 

[67 Falcon]

Your dizzy is out 180 degrees.

 

[Anonymous]

Did the same thing on my conversion, and the problem was that I was off a tooth on the distributor. Pulled it out, turned it slightly, put it back in and fired right up! If you're sure you are not out 180, then it might just be off a tooth.

 

[Anonymous]

For what it's worth, the best DS2 wiring diagram that I've seen is the one here:

http://www.mustangsteve.com/conversion.html

I was able to easily, and neatly, convert my stock harness to fire the coil without any problem whatsoever. No nasty wires in the engine compartment, and it all looks rather stock.

Also, as was pointed out above, ALWAYS make sure that your engine is set to TDC on the #1 cyliner when removing a Dizzy. It's just a good practice, and makes getting everything alligned again that much easier!

Good luck!

 

[Anonymous]

Dizzy was 180 degrees out. Worked on my car from 9am to 7pm...detailing engine compartment, adding export brace and a bunch of other stuff. By 7pm, I was tired. Too dumb to realize that the dizzy was 180 out!

Thanks Guys!