318 will not start

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Magnum87

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Have a 73 Coronet with a stock 318 2 barrel. Just got it. The previous owner said car was running fine until about 2 weeks ago and wouldn’t start- just would crank nothing. Seemed to think it was the fuel pump. Have the car home. And it hit and soon as I cranked it. That’s all I can get it to do is hit. Hits better when holding the gas pedal to the floor. I verified I’m getting spark. I changed the ballast and ECU just to be safe. Also it’s getting fuel u can see it in the carb when working the throttle. U can smell gas also and it’s bad out the exhaust after it hits several times.
Is the car just flooded? I tried starting it with the pedal to the floor and never let up and like I said it hits better but that’s it. Any ideas??
 
Have a 73 Coronet with a stock 318 2 barrel. Just got it. The previous owner said car was running fine until about 2 weeks ago and wouldn’t start- just would crank nothing. Seemed to think it was the fuel pump. Have the car home. And it hit and soon as I cranked it. That’s all I can get it to do is hit. Hits better when holding the gas pedal to the floor. I verified I’m getting spark. I changed the ballast and ECU just to be safe. Also it’s getting fuel u can see it in the carb when working the throttle. U can smell gas also and it’s bad out the exhaust after it hits several times.
Is the car just flooded? I tried starting it with the pedal to the floor and never let up and like I said it hits better but that’s it. Any ideas??
Two things I would do I would have a can starting fluid and try that then I would grab the crankshaft and see if I could turn it back and forth without the cam turning=timing chain worn/chain slack/jumped teeth.

If it fires and runs a few seconds on the starting fluid....the carb has a major vacuum leak, simply even the base plate gasket could be the cuprit.
Overall it sounds like you covered the ballast/ignition box and verified spark...
You can also just spray a lil wd40 on the carb and base gasket and try to start it...and or get it running with the starter fluid then put your hand over the carb and if it all the sudden idles fine.. carb gasket time.
 
I know it’s supposed to be closed when it’s closed. Was just saying. Also no backfires.
 
Random thoughts
Compression
Fuel
Spark

Compression.......any idea how much? Might want to run a compression / leak down test. Might want to ponder "is the timing chain slipped" Has the thing been sitting a lot? Maybe the rings have lost compression, and over-priming with fuel has 'washed the cylinders' lowering compression

Fuel......make sure it's fresh, make sure the plugs are decent and not fuel fouled. Don't be afraid to dump some down the throat....known fresh, that is

Spark.....good spark and at the right time. Just how good IS the spark? Rig a gap/ tester out of the coil, using a solid core wire. Rig it so you can see the gap through the hood gap, and crank it using the key, not by jumpering the start relay. Also does it crank good and "zippy?" How is battery condition? You should get nice snappy blue spark at least 3/8" and typically 1/2"

Might check the timing. You can do that on the starter as well.
 
So much it could be, and very little to go on....
  • Verify you have valve timing... nylon cam gear are always suspect
  • Verify you have spark at the Spark Plug
  • Verify gas is coming out of the carb into the intake (accelerator pump)
Even if you have a major vacuum leak, such as the PVC hose isn't plugged in, it will still start and run but not want to idle.
 
friend had a brand new Edelbrock on a 390 Galaxy. Thing would not start, he called me and I went over, stuck my finger in the open power brake fitting on the back and said "You got a leak". The threaded allen plug was rolling around the bottom of the carb box. hand threaded it and it started right up. I bet you got a large leak, like your power brake hose is unplugged?
 
Ok thanks everyone for the advice. I will follow up and let u know more tomorrow. Just got the car in the garage and I gotta get a few hours sleep for work. I will go with your suggestions and report back starting tomorrow. Thanks again
 
So much it could be, and very little to go on....
  • Verify you have valve timing... nylon cam gear are always suspect
  • Verify you have spark at the Spark Plug
  • Verify gas is coming out of the carb into the intake (accelerator pump)
Even if you have a major vacuum leak, such as the PVC hose isn't plugged in, it will still start and run but not want to idle.


Go pull your pcv hose on your stock 318 and tell me it doesnt still run. More bs

It will still idle in park with the pcv pulled and open on a stock 318.
Fin
 
Go pull your pcv hose on your stock 318 and tell me it doesnt still run. More bs

It will still idle in park with the pcv pulled and open on a stock 318.
Fin
I'm not on ignore still?? boy is that disappointing :(
 
Sorry about the hit part.... means it runs for 2-5 seconds or whatever just a term I have heard other people use over the years
 
Does it "hit" while cranking or does it "hit" a bit with the key in the run position? Not cranking.
 
I had a 318 in a 70 Challenger that had a broken distributor pin/gear. The shop that sold me the car said they tried everything to get it to run. This was 30 years ago.

Does the distributor turn with the cap off?
 
If it "Hits" while cranking, but won't keep running when you release the key, the first thing I would check would be the Ballast resistor.
 
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Had a similar issue years back with my 87 D150...after replacing everything, and I do mean EVERYTHING (fuel pump, fuel filter, orange box, ballast, plugs, wires, cap, rotor, distributer, coil, and carb) it still didn't work....then I found 1 small vacuum leak at the brake booster, fix it and it started right up and ran like a champ.....I felt like a serious idiot after that, lol.
 
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