Jump to content
SASS Wire Forum

Mechanically Inclined


Sawhorse Kid

Recommended Posts

I have a Holley 4160 causing a No Start.

The carb ran just fine before sitting for too long.

The fuel bowl is getting fuel but does not appear to be getting to the throttle body.

I took the primary bowl apart and flushed carb cleaner thru it, All passages appear to be clear.

What am I missing?

 

 

 

 

Link to comment
Share on other sites

Jets and pilot holes. Clogged venturis

 

Remove the idle and high speed jets. Soak in carb cleaner make sure the holes in the sides of the jet tubes are not varnished closed

Link to comment
Share on other sites

2 hours ago, Sawhorse Kid said:

I have a Holley 4160 causing a No Start.

The carb ran just fine before sitting for too long.

The fuel bowl is getting fuel but does not appear to be getting to the throttle body.

I took the primary bowl apart and flushed carb cleaner thru it, All passages appear to be clear.

What am I missing?

 

 

 

 

Spark plugs...Are they in????

 

Texas Lizard

Link to comment
Share on other sites

He's getting fuel to the bowl so his fuel line is good. If it was filter it would run and die then run and die as the bowl was run dry and couldn't be refilled fast enough. 

 

Engine needs: air fuel and spark to work. I second confirming spark. But if it ran when parked your jets are varnished up. 

 

You tube that carb tear down and pull the jets. Clean em with a soft bristle brush and poke the holes clean with a bristle pulled out of a wire brush. AFTER a soak in carb cleaner.

 

I wish I had youtube when I was a much younger poorer shade tree mechanic. Sometimes couldn't afford a Chilton or clymers and just had to figure it out. 

Link to comment
Share on other sites

Lots of possibilities still.

 

Start with a quick ether test.

 

Stuck float will cause flooding and no-start. Especially with an electric fuel pump. Or dying engine after running a few seconds. Ether may not start a flooded engine. Try again the next morning or pull all the plugs to dry them out.

 

Open choke will cause no-start (or hard start/bad idle) when cold. And can cause flooding. Engine will spark up at least momentarily with ether.

 

Bad accelerator pump will cause at least a hard start. Engine should still run if started with a shot of ether but throttle will feel flat/unresponsive (bogging).

 

Clogged idle jets will cause at least hard start (but should still start with extra throttle). And engine will spark up momentarily with ether. Will then run at higher RPMs but not at idle.

 

No spark will cause no start.

 

No air will cause no-start.*

 

Timing way off will cause no-start.

 

A shot of ether on an engine which is not flooded and in reasonably close time verifies air and spark.

 

It does sound like a varnished carb and so it may have multiple reasons for a no-start. Agree youtube for a detailed understanding of all air passages, jets, venturis, float, and any little balls with springs. Choke adjustment, initial idle jet and throttle settings.

 

Verify engine spark timing, and proper routing of any manifold or ported vacuum hoses.

 

The ether test eliminates many possible issues; since the engine has sat for a while, you could also have stuck points.

 

*I once had to pull an intake to get all the nuts out. That is the only no-air problem I have ever had. Have heard of rags used to prevent stuff from falling in getting left in engines and sucked in deeper on first crank.

Link to comment
Share on other sites

11 hours ago, Texas Joker said:

Jets and pilot holes. Clogged venturis

 

Remove the idle and high speed jets. Soak in carb cleaner make sure the holes in the sides of the jet tubes are not varnished closed

This ^^^^

 

I would venture to say a  rebuild is in order. Oh, and don't use wire to clean out the jets.

Link to comment
Share on other sites

Verify that the ignition is firing at the spark plugs. If it is a modern, high compression engine DO NOT use ether to try to start it. You can use aerosol carb cleaner instead. I prefer to use a cloth with a little fresh gasoline held close above the carburetor to start the car.

 

Hot spark

Free air flow 

Clean, fresh fuel 

Proper timing 

 

That last one is as important as anything else for startup!!

 

 Make sure the battery is fully charged and that the starter is turning fast enough!!

Link to comment
Share on other sites

On 10/14/2020 at 11:08 AM, Sixgun Sheridan said:

Holly 4160s are ridiculously easy to tear down and rebuild. Get yourself a gasket kit and clean 'er up this weekend.

 

BTW one flaw in Holly carbs is the power valve. If that tears or gets a hole in the diaphragm it'll flood out and never start.

.

 

All passages appear to be clear, I will check the power valve.

Only now the o-rings in the transfer tube are leaking and the throttle body is still dry.

Looks like a rebuild may be coming in the future.

 

Thanks for the replies.

Link to comment
Share on other sites

On 10/14/2020 at 12:08 PM, Sixgun Sheridan said:

Holly 4160s are ridiculously easy to tear down and rebuild. Get yourself a gasket kit and clean 'er up this weekend.

 

BTW one flaw in Holly carbs is the power valve. If that tears or gets a hole in the diaphragm it'll flood out and never start.

.

 

Reason I switched from Holly to Carter when I was hot rodding cars.  1 or 2 good backfires and the power valve would have to be replaced. 

 

I learned pretty quickly that 4 barrel Holly's were for people that liked to tinker with the carb all the time.  Got tired of always having to tinker with Holly carbs. A good racing buddy turned me onto the Carter AFB series and I never bough another 4 barrel Holly

Link to comment
Share on other sites

The Carter carburetors, (AFB, AVS) were great street carbs until Edelbrock started bastardizing them in recent years.

 

Most people have little business trying to use Holley carbs since they don’t have the knowledge, experience, or patience  to deal with carburetor designed for racing being used in a street application!!

 

At the track, Holley is king when out and out performance and tunability are the order of the day!

 

As for performance AND drivability on the street, a properly prepared QuadraJet is the ultimate street carburetor in the opinion of most top professional builders of Street Machines and Street Rods who still make use of carburetors. They also work well in pairs!

 

Since EFI is now the soup de jour, all of this is rapidly becoming obsolete technology!!

Link to comment
Share on other sites

22 minutes ago, Blackwater 53393 said:

As for performance AND drivability on the street, a properly prepared QuadraJet is the ultimate street carburetor in the opinion of most top professional builders of Street Machines and Street Rods who still make use of carburetors. They also work well in pairs!

But the improperly prepared ones gained them the nickname QuadraFlood.

 

I liked QuadraJets on 350s, with a dual-plane intake, a mild cam (think 'Vette), open exhaust, and low rear gears (makes the combo WAKE UP). Floor the throttle, hang on to the steering wheel and watch the gas gauge drop. But cruising at steady speeds returned great gas mileage for a carbureted engine.

 

If I were to replicate a similar formula today, I would take a serious look at EZ EFI as a bolt-on replacement for the carb. And instead of a basic 350, I would stroke it with a 400 crank to 383. Torque rules on the street.

 

As to the Holley under discussion, it should give better throttle response, as in SNAP response. But tuning the jets as the seasons go by to maintain peak year-round performance is a labor of love.

Link to comment
Share on other sites

OH! I almost forgot!! On the Holley!!  Remove the “power valve” and plug it!! Step the jets up from four to eight sizes, ( depending on engine size and performance level) and the backfire problem goes away.  The power valve isn’t there so it can’t rupture!!

 

You can also speed up the accelerator pump or go to the larger one to compensate for the lack of the power valves!!

Link to comment
Share on other sites

15 hours ago, John Kloehr said:

But the improperly prepared ones gained them the nickname QuadraFlood.

 

I liked QuadraJets on 350s, with a dual-plane intake, a mild cam (think 'Vette), open exhaust, and low rear gears (makes the combo WAKE UP). Floor the throttle, hang on to the steering wheel and watch the gas gauge drop. But cruising at steady speeds returned great gas mileage for a carbureted engine.

 

If I were to replicate a similar formula today, I would take a serious look at EZ EFI as a bolt-on replacement for the carb. And instead of a basic 350, I would stroke it with a 400 crank to 383. Torque rules on the street.

 

As to the Holley under discussion, it should give better throttle response, as in SNAP response. But tuning the jets as the seasons go by to maintain peak year-round performance is a labor of love.

 

One of my current projects is a 406 inch small block with an LT4 Corvette fuel injection setup.  It is heavily modified to work with huge, ported Vortec heads and a nasty hydraulic roller valve train.

 

If I were to go carbureted, I would select a Q-Jet from a 500” Cadillac and do the modifications I learned from one of the top carb specialists in the industry!

 

 I set one of these up on a 465” big block, years ago, and it performed flawlessly!  That one was a square port, solid lifter, open chamber unit running 9.75:1 on pump gas!

Link to comment
Share on other sites

Howdy,

I tinkered and tinkered with a holley.

Finally I hunted up a real carb expert.

He did a complete rebuild and showed me what was wrong.

NO guessing.

After that I drove instead of tinkering.

Do it once do it right.

Best

CR

 

Link to comment
Share on other sites

  • 2 weeks later...

Glad you caught it!!  That accelerator diaphragm is a fire hazard if it goes to leaking!!

Link to comment
Share on other sites

That reminds me of a story. 

 

A co-worker had a CJ Jeep he used to knock around in.  It started but soon died and wouldn't start again.  He traced it to water in the fuel.   Seems his kid wanted to help dad out and fill his tank from a garden hose.  Drain the tank.  Flush the line, etc.  Put 5 gallons of gas back in. Wouldn't start. Yeap, the kid had topped off the 5 gallon can also. :o

Link to comment
Share on other sites

On 10/14/2020 at 9:56 AM, Mister Badly said:

It should fire with a few pumps from the accelerator pumps when cold. It won't continue to run but would confirm that circuit is working.

I had a 1976 Mercury Marquis wagon that had the same problem.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.