Thanks in advance for any help you can give. My son just swapped out a 305 for a 383. Everything seems to be connected correctly. New starter soloniod. Turn the key and all the trouble lights come on. Turn to start and get zip. We've checked the voltage at the starter and all is good. Does the enable start wire from the ignition go through the cpu or is it direct wired to the solonoid? As I said, any suggestions would be greatly appreciated.

 

The ignition goes through the park/neutral switch (auto) or clutch sw (manual), ghen to the starter. Check for +12v (at the shifter)on the heavy yellow wire (comes from ignition sw) while cranking and the heavy purple (from sw to starter). Make sure the shifter is fully in park or neutral and that harness plug has a good connection st the switch.

 

Thanks for the response. We bypassed the ingition relay and the park/neutral switch at the shift and got it to turn over.

I was also wondering about the starter. The compression in the new engine is much higher than in the old 305. Do I need a more powerful starter to overcome that initial compression?

Thanks again for the reply

 

Depending on the age of the start it might not hurt. The compression in my 305 is mildy higher that stock (and not quite the motor as yours) and the starter didn't really seem to enjoy that but, an Optima battery cured it, mostly. Heat (and I'm sure age) is now the starters new enemy.

 

That's what we were thinking. I'm guessing the compression in the new engine to be somewhere around 10:1 or greater. My vette with a stock engine is 9.5:1 so this has to be greater. We had some luck turning it over but can't keep it running. When we set the distributer at a point where it turns over ok then it backfires through the carb. When we advance the timing to eliminate the backfire it's struggleing to turn over. Thanks for the reply and now I guess we'll go out and try something new.