Starts ok. Then won't restart for a few hours.

[Bross82]

When I start my blazer after it's been sitting atleast a few hours, it starts up no problem. If I let it warm up and then shut it off, if I then try to start it back up it will just have the starter trying to crank it over. But, it will not fire. I am getting fuel in the fuel line up to the carb and can see it spraying down into the bowls when this happens. But, it just doesn't want to start up for a little while.

There are a few things to keep in mind. I recently changed the carb with the same Edelbrock Performer carb that was on there before. The truck had sat a while and would no longer start at all. Replacing the carb has fixed the initial starting issues. The new carb has not been tuned since it was installed. This I thought could be done after getting it driveable, but, didn't expect it would necessarily cause starting issues (though I could be wrong). I also often have difficulty shutting the motor off without it dieseling (having pre-ignition...). I will need to put it in drive and then step on it a bit when I turn the key off to try and get it to cleanly shut down. Is it just doing this along with an "untuned" new carb is flooding it when it does shut down? I had to shut it down this way with the old carb, but, didn't have the flooding issue. Any ideas?

Thanks!
Matt

1985 K5 Blazer 305, edelbrock 600 cfm 4 barrel performer carb

 

[fmstruck]

When you say it tries to crank, you mean it cranks hard? Check the ignition timing. It should be 8-10 degrees btdc with the vacuum advance unhooked. Also pull the distributor cap and check to see that the mechanical advance is working freely and the springs will return it.

 

[Chevy305]

agreed, get the timing in check, then check the choke make sure it is opening fully at tempurature.