500, 472, 425, 368 Discussion, Newbie Needs Some Help in Cadillac Engine Technical Discussion; After hours of Google searching and reading through this forum, I figured I would go ahead and join even though ...
After hours of Google searching and reading through this forum, I figured I would go ahead and join even though I don't own a Cadillac.....yet. Maybe one day I'll get an early CTS and set it up with an LSX. But for now I have my Silverado SS and hope to buy the "Chevrillac" I'm piecing together for a buddy. With that said I hope I'm still welcome here.
Now, what the Chevrillac is...... 1972 C10 on 44's, Dana 60 and Dana 70 diffs, divorced NP205, and a built turbo 400 behind a 68 472. MSD 6420, MSD 8680, HEI converted with a Mallory distributor, and Taylor wires. A pretty nice setup for a streetable mud truck.
I love older cars, but have more new school knowledge, hence my problem and part to why I'm here.
The problem: Parked the truck to replace the flexplate and starter after the previous owner thought the motor was a 75 500 and had the wrong starter on it. I also installed a 12 under the seat and the stock Bose speakers out of my truck with an old Sony HU. I seriously doubt that would be the cause to my no start situation now. I had the Holley Qjet rebuilt after the primary started leaking through the pump and also discovered I no longer had spark. Tracked down the timing control unit went bad and now have spark, fuel, and crank, yet no start. I never took the dizzy out and my buddy changed the plugs. I assumed he placed them back wrong, set 1 at TDC on compression stroke and did the wires all over. Still won't fire. I have gone through everything over and over and still can't figure it out. It cranks over and sounds like it wants to fire, but all I'm getting is a bit of a "poofing" back through the carb. The rotor is fine, coil is brand new too, and the magnetic pickup on the dizzy seems to still be working.
If anyone can help me get this thing purring again, it would be greatly appreciated.
Sorry for the extremely long first post guys. Just trying to be thorough with the info. I look forward to making some friends here and learning more about these powerhouse motors.
Your timing may have jumped a tooth.. If you still have the stock timing gears , you have a real good chance,,, the stock gears are plastic coated to run quiet...after all these years the plastic always breaks off and makes the chain loose...when this happenes they can jump timing eazy..If you do end up changing the chain and gears use the Cloyes brand and use there best set..there about $100.... Take out #1 spark plug, thats on the passangers side... find the topdead center, maybe by using a coat hanger wire and turn it over by hand and find the TDC and now check your timing mark and see if it is close to zero..
Pretty sure it didnt jump a tooth and the set has already been changed. Truck rips through deep mud no problem, the crank bolt has been replaced, and the front cover has been removed for some reason previously. I set 1 at TDC on compression stroke several times for reassurance and reset everything. Dizzy rotor is at about 1 o'clock right? You can watch the piston through the spark plug hole and tell when its coming up and going down. Even double checked by blowing a paper towel out of the hole and by checking the rockers. I've got 12v to the Msd, verified spark and fuel, but she still wont fire and run. I don't want to keep trying to turn it over without it running to avoid me having to change the rings. Compression is good too. Low cylinder at 148 (#2), high cylinder at about 161 (#7). Not even a 10% difference, so any other ideas? I don't have a timing light, dizzy was never removed, and the truck ran fine.