I have been driving my 75 blazer with pride and joy the last couple of weeks but yesterday when i took it to the store to buy some stuff it refused to start. Engine is a 350csb carb.

cranks over fine and wants to start... but it doesnt.
replaced fuel pump today on the parking at the store... fun but still wont start.

The only time i can get it to start is if i hold down the gas pedal max and crank for a while, then it will start, run verry un-even and if i let go of the gas it will stall out... I can see some smoke coming from the distributor but i guess its from excessive cranking? Or can there be a clogging somwhere?

spark plugs and cables, distributor, carbeurator is fairly new.. still seems to be a gas issue since it starts when i hold down the gas pedal... Doesnt feel like a setting issue since it has been running for a year like this and now just refuses to start...

any suggestions on what to check next? Thanks.....

 

verify you have spark, check fuel filter, check for vacuum leaks. If all else fails check timing too.

 

Sounds like the carburetor is flooding. Rottenchester Carbs are famous for this when the plastic float gets soaked in ethanol added gas since they were never designed for ethanol. Float gets heavy and gas pressure blows the needle off the seat and causes flooding.
Best way to check is pull the air cleaner off and then crank it over a few turns and then look to see if gas is dripping into the carb bore. If this is the problem pull the carb and get it fixed then change your oil. (It will smell like raw gas)

 

Um, smoke coming from the distributor is not a good thing. It will not smoke due to excessive cranking.

What carburetor are you using?
Are you running a HEI distributor?
Have you pulled a plug to see what they look like?

Have you checked your grounds? A weak ground can lead to a low voltage situation at the plug and not enough spark to burn the mixture cleanly.

 

Hi Guys... thanks for replying.. went back to the store and got it to start by having the gas pedal down to the bottom.. then drove it home with constant pushing on the gas pedal... It was hard at red lights but neutral in and just giving it some gas did the trick...

Il be checking all your tips tomorrow... atleast its at my garage now

Carb is a edelbrock one.. Im pretty sure its an HEI dist.

Engine was running verry bad/slow/sliggish and a lot of black smoke came out...

Should not be any timing issues since it has not been touched at all.. Just from driving perfectly to not start without full gas pedal down.. Why do i feel like its lacking gas?

Also... the first thing this morning it started just fine and ran just fine.. then i turn it off and it has the same problems all over again... should never turn it off i guess :=)

Thanks!

 

"Engine was running verry bad/slow/sliggish and a lot of black smoke came out..."
Edlebrock Carburetors can have the same float problem. The thick black smoke is the biggest sign that it's flooding. (In fact any carb with a plastic/foam float can)
Also when its flooding like that it contaminates the engine oil with raw gas. My half brother destroyed an engine in 5 miles by driving it while it was flooding.

I have an RV that does this on a regular basis. I have to rebuild the Carb every three years because the ethanol in gas dries out the gaskets and eats the float. At first it would do this every third start and then every other...Finally it wouldn't start at all without flooding.

I said all that to say this...Check that Carb to see if its flooding (Or the choke is stuck shut) Before it ruins your engine.

 

Thanks for all your help, i actually fixed it today.. turned out to be the easiest thing... bad ground strap.. put in a new cable and now it fieres right up all the time

Thanks for all your help, i will be looking out for flooding and will be replacing some old parts due to this.. better to be proactive then reactive in these cases!

BR Jonas

 

A bad ground caused that? I was thinking it was flooding, as well, like 1000monkeys was saying. Thanks for updating the thread with the fix. I'm sure this will help someone in the future.

 

Sometimes it is the easiest thing....

FYI monkey, edrlbrocks have brass floats. But rebuilding every couple of years is good idea anyways.

 

Hi again, engine is still running great...

However i was going to ask you knowledgable guys about the carbeurator..

Image taken today, should the lids on the carb always be in "open" state like this?




The lid felt like "locked" in that position even tho i have seen them move in other peoples videos :P