SBC only wants to start with starter fluid.

[Alxrez]

Hey guys. Wondering if you could help me out. I have a Holley 650 Street Avenger that won't start my SBC. It sounds like it wants to start ONLY when I use starting fluid, but doesn't actually run. Even if I crack the throttle, I can see the fuel squirt in there, but I get no response. Fuel psi is steady 6. Any ideas?

[BITE_ME]

You need 3 things for the engine to run.
1. Air.
2. Fuel.
3. Spark.

I would check timing, then check spark at all the plugs.

I said all. Because I fixed a V8 that had seven bad plugs. It only had 2 hours of run time on the new plugs.

[69cam]

As stated above. Make sure your actually getting spark to the plugs.
Check your firing order, and make sure your #1 plug is where the rotor is pointing at on the distributor. If you have to, pull the cap and the #1 spark plug. Put your finger over the plug hole and turn it over. Watch the rotor every time it pops your finger, so you know where #1 should be firing.

[Alxrez]

As stated above. Make sure your actually getting spark to the plugs.
Check your firing order, and make sure your #1 plug is where the rotor is pointing at on the distributor. If you have to, pull the cap and the #1 spark plug. Put your finger over the plug hole and turn it over. Watch the rotor every time it pops your finger, so you know where #1 should be firing.

Thanks for your reply. I got a chance to work on it today.
I'm not pumping the pedal, because I really want to avoid flooding it.
I've done it before. So I've only been using starter fluid. But carb does squirt out fuel as it should.


Today, I threw in a fresh set of plugs. Triple checks wires are going to correct cylinder.
Also, I know timing is correct, as I used a piston stop on cylinder #1 on compression stroke.
It rotated backwards and divided between the two marks to find true top dead.
I was getting some backfire out the carb, but rotated distributor until it stopped happening.
I was able to get it to run for about 3 sec. By continuously spraying starting fluid.

[BITE_ME]

I always pop off a valve cover, and watch that the intake valve is closing, to find top dead center.

Did you screw the idle all the way in, then out 1-1/2 turns? There's two of them.

[Alxrez]

I always pop off a valve cover, and watch that the intake valve is closing, to find top dead center.
Did you screw the idle all the way in, then out 1-1/2 turns? There's two of them.

Yep, sure did. This is driving me nuts, even had a dream about it.

Would you mind looking over this pic? Anything out of the ordinary?
That hole in the middle, and the ones above & under it, look really black?
To they feed fuel for idle?

[Danny Cabral]

That hole in the middle, and the ones above & under it, look really black?

These Holley carburetors only use six screws, even though here's eight threaded holes.
The two center screws aren't utilized because if they loosen, the engine would ingest them.
http://forums.holley.com/showthread....&p=686#post686 (Similar Forum Thread)
That center fitting, looks like a replaceable idle air bleed jet. (?)

To they feed fuel for idle?

No.

[BITE_ME]

On the lower right is the most infamous Holley set screw.
It's used to help tune the carb some times. If the idle mixture screw have no effect when turned.
Do to the fact that Holley's and any carburetor that has separate primary & secondary fuel bowls.
The fuel in the secondary will get old. So the secondaries need to be open just a small amount to allow fresh fuel in the secondary bowl all the time.

Anyway: I would remove the idle mixture screws, and spray some compressed air/carburetor cleaner in their mounting holes.

[Alxrez]

That center fitting, looks like a replaceable idle air bleed jet. (?)

Do you think if it was clogged, it would keep the car from idling?

[Danny Cabral]

Do you think if it was clogged, it would keep the car from idling?

It's possible, IF it's an idle air bleed jet. The secondary throttle blades appear to be open too far.

[BITE_ME]

Do you think if it was clogged, it would keep the car from idling?

I believe that's the power valve protection unit.
It should still start up if it's plugged.


Edit: The internet sucks.
It does not know what that part is for.
I've got 8 Edelbrocks, and 3 Rochester's. But no Holley's in front of me to see what passage it goes too.

[81 TransAm]

Someone has had this carb apart. Look at the mismatch screws on the base plate. Is it even the correct base plate?
I would totally disassemble it to see what is wrong.
We can make all the guess's we want. But if you want to know, take it apart.

[Alxrez]

So I was going over this and looking at the vacuum lines, and started wondering if I had it correct.
I'm running a line from the "full vacuum manifold" port to a vacuum tee that's on the manifold. Is this right would this cause it not to idle?

[BITE_ME]

I'm running a line from the "full vacuum manifold" port to a vacuum tee that's on the manifold. Is this right would this cause it not to idle?

You don't put a vacuum source to another vacuum source.
Or putting it another way: You don't put two "suckers" together. One "sucker" could be stronger than the other.

Are you sure your using the right spark plugs?
What's the make & model of the cylinder heads and spark plugs?

[TIM FRY]

Cam timing off, distributor timing off, or both. You get accel pump fuel, so carb is filling. Check to know for sure you base gasket seals on the manifold and the carburetor, both together. Good luck.