Am I Cursed by the Carburetor Gods? Or do I just suck with Carburetors?

[jjester6000]

When I first bought my '74 it has the original Rochester Monojet Carburetor.

It always ran rough, despite replacing the entire ignition system and trying my best to tune the carb.

I then went into my first carb rebuild (other than on lawn mowers) and was very careful to get it right.

To my suprise it actually still ran, and a bit smoother than before, but it still fell on its face above 60 mph.

This lead me to cave in and buy a certified rebuilt carb, and it still ran rough, but had an electric choke and didn't bog down anymore.

It lasted about year, after two rebuilds I got fed up with it, and ordered a cheapo carb off of amazon, and that fixed the issue.

Something goes wrong with the accelerator pump or something because It always wanted to fall on its face and would ping, and would never ru n consistently enough to figure out the problem.

Not 6 most later, the new one wants to bog at medium open throttle and won't go above 45.

After pulling the head an fixing a burnt exhaust valve, it didn't change anything except make the engine run smoother.

Still fell on its face.

I pulled this new cheapo carb, and didn't find anything wrong, so I slammed it back together again without even cleaning it, and it worked flawlessly.

I then blew the motor and put this same carb on my new one.

Soon, it became pretty much undriveable and had the same issues but worse.

Pissed off, I bought a certified rebuilt Carter YFA (I was my only running car at the time and I needed it running again) and adapted to the 250, and it ran the best it ever had.

Fast forward to now, and the truck floods out, boggs down, leans out, backfires, pings, and every other possible carburetor problem you can have.

I am disgusted, it ran perfectly, then all of a sudden just screwed up.

Now I need the truck again, so I just ordered yet another cheapo Rochester Monojet knockoff just to get it running again.

Isn't the definition of insanity doing the same thing over and over while expecting different results?

Anyways, that's the end of my extensive Carburetor related memoirs.

What 1 barrel Carburetors actually work?

Am I cursed by the Carburetor Gods?

Should I just get Holey EFI?

Do I just suck at tuning carburetors?

I just need something that will run consistently, that Carter YFA makes me sick to my stomach on how it manages to run so inconsistently.

No matter what I did (I change the cap, rotor, points, then even the entire distributor) it made no difference. I rebuilt it again and found no problems.

Anyways, I'd like to see your feedback.

 

[CRM]

Have you checked the fuel pump and fuel filter?

 

[Frankenchevy]

^that or maybe..

A collapsing fuel line?

You check how good the wiring is to your coil?

You have power brakes? Maybe a vacuum leak in the brake booster.

 

[gotyourgoat]

So the current count is 4 carbs?

 

[Curt]

Ya that sucks.Ditto on the fuel pump.Maybe the sock in the tank?

surely not bad gas at same station?

timing?

vacuum leak?

 

[jjester6000]

I know for sure it is the carburetor (new fuel pump, fuel lines, and no difference). Even after running it out of a gas jug (in case there was a clogged fuel line) it made no difference.

 

[jjester6000]

I'll say that the used engine I put in the truck has no rings left, but compression is at least consistently bad (between 90-100) and it has a whole new top end.

When it idles, it is really smooth, but it just keeps going from running perfect down the road at 70mph, to not even wanting to run and backfiring.

One time it flooded out at a stop sign and sprayed flames out the exhaust (not just a back fire, but a continuous flame that burn't up some of my fresh paint.

Anyways, every time it had any running issue, it always seems to come back to the carburetor.

I rebuilt the cylinder head for what turned out to be a carburetor problem on the previous engine.

 

[jjester6000]

^that or maybe..

A collapsing fuel line?

You check how good the wiring is to your coil?

You have power brakes? Maybe a vacuum leak in the brake booster.

The fuel system is not the culprit since it will sometimes run perfect, sometimes lean out and bog, sometimes flood out and shoot raw gas/flames out the exhaust (not just a backfire, but a continuous flame) and sometimes refuse to run at all.

It is so inconsistent. The only vacuum accessory I have hooked up is the advance, and sometimes it likes it, sometimes it doesn't.

Sometimes I think I have it fixed, and sometimes it just doesn't run.

I am really fed up. At least with the monojet the problem was consistent, but with the YFA it just has a mind of its own.

 

[jjester6000]

Is there a good aftermarket, or swap on carburetor out there for these engines?

What problems have you guys had with monojets?

Should I find an early Rochester 1 barrel?

 

[Curt]

This is HEI Ingintion?Module?

I know that a new battery completely changed my truck’s performance.Even though I was show 12 volts at the distributor,when tested,the alternator was constantly putting a huge effort to the battery.

Probably what killed my module.It was a slow death,then finally just gone.No start.New module and the truck starts and idles way better.New battery too.

Obviously you’ve checked your gap and plugs.

it just seems carb after carb.I would lean to something else.Engine running cold?

 

[gotyourgoat]

it has the original Rochester Monojet Carburetor.
1
me to cave in and buy a certified rebuilt carb, and it still ran rough
2
and ordered a cheapo carb off of amazon
3
bought a certified rebuilt Carter YFA
4

first carb rebuild
1
after two rebuilds
2&3

Am I cursed by the Carburetor Gods?

The above are all your words @jjester6000 copied an pasted.

Current count 4 carbs and 3 rebuilds.

When a previous owner stripped and altered my original carb to a useless quality of which National Carburetor literally laughed at me. I bought a rebuilt stock quadrajet for my year. It has been on there ever since. That was like 6+ years ago. Haven't ran it in a week and when I go vote tomorrow it will turn on after some cranking and wake the neighborhood up.
Never adjusted it although I have been thinking about it.

So, yeah you seem to be cursed.

 

[CRM]

A flame coming out of the tailpipe suggests an ignition problem. I know that you are positive that it's the carb, but 3-4 carbs and it still has an issue? Have you checked the timing and firing order? Does your engine use an EGR system?

 

[jjester6000]

A flame coming out of the tailpipe suggests an ignition problem. I know that you are positive that it's the carb, but 3-4 carbs and it still has an issue? Have you checked the timing and firing order? Does your engine use an EGR system?

This is over 2 years, 2 different engines, and many different problems that seem to have been fixed after replacing the carb.

 

[jjester6000]

A flame coming out of the tailpipe suggests an ignition problem. I know that you are positive that it's the carb, but 3-4 carbs and it still has an issue? Have you checked the timing and firing order? Does your engine use an EGR system?

It doesn't currently have an EGR Valve, but it did before swapping the motor.

 

[jjester6000]

This is HEI Ingintion?Module?

I know that a new battery completely changed my truck’s performance.Even though I was show 12 volts at the distributor,when tested,the alternator was constantly putting a huge effort to the battery.

Probably what killed my module.It was a slow death,then finally just gone.No start.New module and the truck starts and idles way better.New battery too.

Obviously you’ve checked your gap and plugs.

it just seems carb after carb.I would lean to something else.Engine running cold?

It still has points, but I they are brand new and set correctly.