Tbi - 350

[Ryanz]

I have the original 350 in my 72 Blazer CST. Previous owner put a Holley carb on which is great when it works, but is finicky to weather conditions, and seems to have a float that sticks and causes it to flood randomly - about once per month.

I'd like to go to an EFI of some sort so that I know exactly what I'm getting each time I turn the key. Any recent suggestions? I've seen some older threads but they're from a few years back. Would like to as non intrusive and keep as much stock as possible given original motor, etc.

[SeventyOne]

Originally Posted by Ryanz

I have the original 350 in my 72 Blazer CST. Previous owner put a Holley carb on which is great when it works, but is finicky to weather conditions, and seems to have a float that sticks and causes it to flood randomly - about once per month.

I'd like to go to an EFI of some sort so that I know exactly what I'm getting each time I turn the key. Any recent suggestions? I've seen some older threads but they're from a few years back. Would like to as non intrusive and keep as much stock as possible given original motor, etc.

Few things first...

Do you have the choke set up and working? Perhaps adjusting it is all you need. Also you live in Canada, right? You're just going to need to set the choke a couple times per year given you actually have seasons.

Fo the float/flooding...you could just rebuild the carb? All this is to say you could get great results by spending a little time and money.

But if your heart is set on EFI, go for it. Also original motors don't really matter in these trucks value-wise. So don't let that hang you up. An LS swap for instance will at least retain and likely raise the value of your K5.

[Ryanz]

Well when I bought it 5 years ago with the original motor I had my heart set on keeping it all original, outside of tires and wheels, but even those I want to go from my rallies to steelie whites with dog dish for the vintage look.

I hope I get the money out that I've put into the rebuild (if I ever sell) as it was a hell of a lot more expensive and hassle than putting in a Crate.

I think I'm leaning to just put an original intake and quadra jet carb, with stock breather to go the distance. I'm this far into it.

In the meantime, the holley, when not sticking, has been perfect. We sprayed some high potent cleaner in it today while revving to hopefully help free it up. It's just always ran rich and stinks badly of raw fuel in my garage. The choke is working fine.

Originally Posted by SeventyOne

Few things first...

Do you have the choke set up and working? Perhaps adjusting it is all you need. Also you live in Canada, right? You're just going to need to set the choke a couple times per year given you actually have seasons.

Fo the float/flooding...you could just rebuild the carb? All this is to say you could get great results by spending a little time and money.

But if your heart is set on EFI, go for it. Also original motors don't really matter in these trucks value-wise. So don't let that hang you up. An LS swap for instance will at least retain and likely raise the value of your K5.

[geezer#99]

There used to be a guy in Stoon who sold tpi and Tbi kits at all the swap meets.
Don’t know if he’s still around.
Maybe check at the speed shops. They might know him.
He was a distributor of Howell too.

https://howellefi.com/product-catego...lete-tbi-kits/

Running rich can be a sign of too much base idle throttle opening.
What’s your idle rpm?
What’s your timing curve like?

Just for humour, got any stoonberry pie?
I got a craving!

[truckster]

Originally Posted by Ryanz

I think I'm leaning to just put an original intake and quadra jet carb, with stock breather to go the distance.

There's a reason GM used the Quadrajet for so many years. You can get a pretty nice remanufactured and flow tested Quadrajet from National Carburetors. The last time I looked (last week) they had a sale going on that knocked the price down under $200.

[jaros44sr]

Originally Posted by Ryanz

Well when I bought it 5 years ago with the original motor I had my heart set on keeping it all original, outside of tires and wheels, but even those I want to go from my rallies to steelie whites with dog dish for the vintage look.

I hope I get the money out that I've put into the rebuild (if I ever sell) as it was a hell of a lot more expensive and hassle than putting in a Crate.

I think I'm leaning to just put an original intake and quadra jet carb, with stock breather to go the distance. I'm this far into it.

In the meantime, the holley, when not sticking, has been perfect. We sprayed some high potent cleaner in it today while revving to hopefully help free it up. It's just always ran rich and stinks badly of raw fuel in my garage. The choke is working fine.

I would check for leaks in the fuel system, hoses? when its not running shouldn't have a strong fuel smell, can you put a piece of cardboard down to see if anything shows up? or puddling at the base of the carb?manifold

[SeventyOne]

Originally Posted by Ryanz

In the meantime, the holley, when not sticking, has been perfect. We sprayed some high potent cleaner in it today while revving to hopefully help free it up. It's just always ran rich and stinks badly of raw fuel in my garage. The choke is working fine.

The fuel smell in the garage is likely not the carburetor. If it's running rich, tune it so its right. You get what you give with a carb. Put some time into figuring it out.

Also not sure how spraying cleaner at the carb while revving will do much for the floats.

If I were you here's what I would do. Get yourself a AFR gauge. If you end up going EFI down the road you'll need the 02 bung/sensor in your exhaust anyways. In the meantime you can get some actual readings to see how rich you are. The sticking float still needs to be dealt with though.

Lastly make sure your ignition is 100% solid before tinkering with the carb.