Blazer wont start

[tdcombs]

Ive got a 72 Blazer that wont start till its warm. The guy that had it before me put a 383 in it (or at least told me he did) that ive never been impressed with. Dont think it has the right cam. And a Carter carb with no choke. Even when its warm outside it doesnt want to start till i shoot some either down the carb.

Even after i get it started I have to rev it up for a few min before it will drive. But if i drive it for awhile and shut it off it starts right back up. I really like this body style truck and with the weather getting warmer i want to be driving it. The old gas tank had a hole in it and im in the process of replacing that so i dont know if that will help at all or not.

Any ideas on what i need to do?

 

[Pookster]

I am very unfamiliar with carbs- but Im going to take a guess at it.

1. Your fuel might be old- Might even have water in it. I would get that tank replaced/repaired and cleaned.
2. Try a new fuel filter. Somtimes they are clogged so bad, that it will stall out.
3. See if the carb needs cleaning.

 

[diesel4me]

Probably the choke...

I have a 625 CFM Carter carb on one of my trucks--its choke often sticks open due to infrequent use,and it makes it hard to start--you have to pump the pedal many times,then it will fire up and die a few times--once you get it running,you have to hold it at fast idle for several minites(the colder it is,the longer you need to "warm it up",to prevent stalling when you put it in drive)--after its warmed up it runs great-

.-I tried spraying the choke with carb cleaner--it has a little piston inside the carb under the black plastic cap that is the culprit for making it stick in the open position...after I freed up the choke,it starts much better--if anything its now too rich,and it loads up!--this lasts about a month or two,after it sits that long its time to spray it again and free it up again..

.Edelbrock carbs are clones of the Carter AFB.and have the same symptoms with the choke--I put a hand choke on my Edelbrock performer on my other truck--that one starts with one turn of the crank,cold or hot..

The gas tank could very well be contaminated with water,rust,and old fuel as already suggested...old gas doesn't "light" like fresh gas will,it loses volatility after it gets old,all thats left is a shellac type of varnish that wont ignite easily--water definately does not help either....

 

[tdcombs]

Thats why im replacing the gas tank. Just have to get a few new hoses to put on it then ill have it in and i think that will help some. The sending unit looked like crap when i took it out, rusty in color. Changed just the fuel filter but that didnt help. My carb doesnt have a manuel or automatic choke on it. Is it hard to add an automatic choke? I just dont want to spend a bunch of money on something that isnt the problem so looking for advice on what all could be the problem.

 

[tdcombs]

It doesnt have a choke. So i would understand why its not starting cold but would think it would start right up when its warm out

 

[Thunder]

Your problem is No choke. The engine needs a rich mixture to strat and run when it is cold. (even if it is warm outside). If your carb does not have a choke all you can do is pump the accelerator a lot to get it to start.
The best fix for your problem is a new carb with a choke.
Its strange there is no choke..... most Carter AFBs I have seen have the choke flapper and tower. Did someone cut it off? If you still have the choke tower and flap maby all you need is a manual choke kit to make it work. They are cheap.

One other thing I thought of is. While you are replacing the tank be sure to check all the fuel lines from the tank to the engine. If they rust out and get a pinhole leak the fuel pump will suck air instead of gas and make for hard starting problems also.

 

[tdcombs]

i guess i meant no auto or manuel choke but the flapper and tower are there. If im gona add one i want to add an auto choke. Really i want to go to fuel injection but not sure how much that will cost. But if im gona need a new carb anyway......

Im hoping to redo the entire drive train in the next year.

Hopefully ill get the tank installed this weekend and itll start and run great but im not betting on it. The blazer has been modified quite a bit by the prevous owner and im pretty sure he had no idea what he was doing and its causing lots of pains in the butt for me.

It needs LOTS of work but i got it cheep $1250, at least i thought that was cheep. I can live with some rust if i can just get it starting and running good.