‘71 302 is still not getting gas when the accelerator is pressed. I installed a new fuel pump a while back, and after going over all the hoses and fuel lines, is it possible to install the fuel pump wrong? Truck will idle but will not rev when accelerator is pressed.

still don’t know why I can’t get gas to the carb. Installed new fuel hoses, new fuel pump, new carb, checked to make sure there is no air sucking anywhere.

 

On our '72 390cc we had similar problem but with non-start, very little gas flow to carb. Thought maybe bad carb. So bought a 2150 to replace the original 2100 that was on it. That didn't help. Fuel flowed when cranking but seemed low to us. Friend suggested replacing fuel pump. Taking fuel line from tank off the fuel pump started flowing like crazy out of the end of the hose. So that showed us there was no restriction between the tank and pump. Putting on the new pump, truck started right up after about 5-10 seconds.
Have you checked the flow of gas out of the tank? Fuel should flow with just gravity. Could be, if your tank is original, and the sending unit is original, that perhaps it is all fubar'd up and the flow is constricted before fuel gets to the pump?

 

Verify the accelerator pump is working. With the truck off, take the air cleaner off and look into the bore of the carb. Open the throttle with your hand, and you should see squirts of fuel come out of the boosters. Give more info about the carb and what it does when you give it throttle? Sputter, dies, missing badly?

 

Gas flow is perfect from tank to pump, and I’m getting gas to the carb. Carb is pushing gas into the manifold, so I don’t have a fuel issue (that I’m aware of).

when it turns over, it idles rough for anywhere from seconds to minutes. When you press accelerator the engine does not rev up and dies. Yesterday I replaced spark plugs and valve cover gaskets and today can’t get it to turn over. May have spark plugs too tight? Also charging battery because ran it low working yesterday.

Thinking it may be blown head gasket or intake gasket? Thoughts?

 

heh..."spark plugs too tight".
Have you checked your timing? Have you checked if every spark plug gets a spark (can do so with the timing light as well).
Does your distributor's vacuum advance work?

 

spark plugs work, I checked the vacuum hoses and no leaks. Tried blowing into the advance with the hose but nothing in the cap moved (didn’t have anything else).

 

you can suck on the vacuum advance hose, not blow.
When vacuum is applied, the lever inside\under the distributor will move.
This is the "advance" that is applied when the accelerator is applied so that timing advances to keep up with the flow of gas.

 

It moves some but won’t hold suction.

I know timing is an issue too, waiting on light from a friend.

 

This is based on your comment about it not revving when you push the pedal, or is it also based on you not seeing fuel squirting out of the accelerator pump nozzles in the carb?
If just the pedal, have you verified that the linkage is working by manually pushing the throttle lever on the side of the carburetor back?

Yes, it's possible. Not easy, but it can be done in some cases. Especially where the pump is defective and the arm bent in the wrong angle.
But has it ever run with this new pump, or did it get installed and then sat while you worked on other stuff? If it worked for awhile, then sat for a longer while, the pump could just have gone bad from sitting.
If it never was run, then it's likely still good. But that can be tested by putting the output hose into a bucket and cranking the starter. There is a specification of something per 30 seconds, or per minute, but I don't remember it. The others will though, and someone posted it up just the other day on one of these forums.

If you dribble gas into the float bowls through the vents (not the throat of the carb, but the bowl vents) to fill up the float bowls, how does it run then?
This will tell you whether it's carburetor or fuel delivery related.

The fact that it idles means it's getting fuel obviously. Are you dribbling it into the carb during these times, or is it running off of fuel delivery?
If it's got fuel in the carb (even a tiny bit) it should rev up.

How do you know you're not getting fuel to the carb? It's idling, so you have fuel.
If it's just based on the fact that it won't rev, then it's possible you're correct. But it's also possible there is something else wrong.
Is the choke butterfly closing when cold, and opening all the way up when warm?

How did you check for air sucking?
What new carb? Was it set up during install, or just right out of the box?

Then why do you think it's not getting fuel as you said before? Why would you think it's a fuel pump issue, when it's actually pumping fuel into the carb?
If the carburetor has fuel in the float bowl, that's all it needs to do it's job. It sounds more like the carburetor is at fault here then, rather than the fuel pump.

Have you checked to see if the choke pull-off is working? Rough running can be the stumble of being lean because the choke is not closing, OR it can be the burble/chugging of the choke plate closing too far.
Next time you start it up and it runs rough, you should take the air cleaner off and by hand open up the choke plate slightly. As you move it more and more open, if it starts running smoother, your choke is set too far closed and needs to be adjusted.

When it's not running, look down the throat of the carb and push the throttle lever open to see if you see two nice steady streams of gas. If you don't, your carb is faulty or you don't have enough gas in the carb after all.

If it won't crank, or cranks slowly, it's got nothing to do with new spark plugs.
If it won't fire, then it could be that some of the plugs are not working.

Doesn't work that way. There is a specification, but too tight will not stop it from working. It might break the plug or strip the threads, but it won't keep it from firing.
A good practice when changing plugs though, is to clean the surface of the seat where they mate up. Any grit can keep it from sealing properly, and any oil can reduce the effective ground connection to the engine.

Hard to say. No real indication of that yet, since you haven't ruled out many other things quite yet.

How did you verify this? Visually looking for spark at each one? Or with the timing light? Either way is good.

How did you check? You can't do it visually. Has to be tested while the engine is running, or with it off using smoke.
Several methods, but there are other things to do as well, such as making sure the carb is tuned and the ignition timing is correct.

It's not from blowing. You have to suck on it. It's a vacuum advance, so relies on suckage only.
You can test it without sucking yourself though. If you don't have a vacuum tester, you can pull the cap and rotor off, manually push the advance arm/lever into the vacuum advance can, put your finger over the vacuum hose or port, and see what happens when you let go of the lever.
If it springs back instantly, your vacuum advance is leaking. If it holds solid, then it's perfect. If it slowly springs back into position it could be starting to leak, or your finger is not sealing as well as you'd like. Seen it both ways.
While you're doing this you can feel if the mechanism is smooth and even too. Any chunks and clunks mean that the distributor could be wearing out.

But having no advance will not keep it from revving up or cause it to die under acceleration unless the initial timing is already too low. Having full manifold vacuum acts different from ported vacuum too. But you can run the engine up to normal speeds with no vacuum advance at all. Just set the initial at over ten degrees before TDC and it should at least run on mechanical advance.

There are more tests to be done I think, but first let us know if you have tuned it, set the timing with a light and not by sight, set the carburetor's choke and other settings rather than just use it out of the box, and made sure it was the proper carb for your engine. I would say fully half the new or rebuilt stock replacement carburetors are the wrong one the first time. Unfortunately, by that time most purchasers have also gotten rid of the original by turning it in as a core.
And unfortunately too, Ford, in their infinite wisdom, used probably four or five different intake manifold, spacer plate, and carburetor base designs that don't always work in combination with each other. Add to that all the different combinations of base gaskets, and you have a recipe for disaster if you don't know what to look for.

And lastly, by any chance did you ever change anything on the front of the engine? Particularly the harmonic-damper? If so, you may need to re-verify your timing since Ford also used at least two, if not three distinctly different timing mark locations on 302's over the years. So whether you have a 289, 302 or 351 Windsor, your timing has a HUGE chance of being skewed off if you have ever replaced either a timing cover or a damper.

Good luck.

Paul

 

as 1ton suggests, there are alot of tests that can be done. Once you get that timing light, you can determine if a charge is getting to each of your spark plugs during idle.
The manual test of the vacuum advance is a good one to also see if it loses vacuum. If it moves while you have the hose blocked off with thumb or plugged, then you know the diaphragm is leaking. Easily replaceable ... just watch out for that tiny c-clip (helps to have a magnet pen or rod).

For myself, after cranking for about 7 seconds, I was only getting about an ounce of fuel. That just didn't seem like enough to me at the time so that helped move me to replacing the fuel pump. And, if you can crank the engine and get gas out of the carb-side fuel line, then the pump is not put in wrong. While it can be done, it is highly unlikely to be done.

Are you saying that you can see the 2 streams of gas flowing in to the carb ports when you open the throttle?

Sounds like this could be due to bad choke setting. There are some really good videos online about how to set that choke. Are you using the hot-air choke or electric? Either way, you need to adjust\twist the choke to set it appropriately at first start.

THen on the other side of the carb (drivers side) you can set the cold idle start to give cold start a little extra rpm.

 

Woah...thanks for all the comments and ideas! Too many to go back and answer completely...

Ive ruled out all fuel aspects, plenty of gas getting to carb. Carb has gas getting to it and functioning. Carb is just needing work/adjusting - came out of the box, but I still have the original that I plan to rebuild and use if can’t get this new carb to work. New carb has electric choke as well. Any recommendations on where to hook that up - read someone used S-terminal ok alternator.

The distributor vacuum was leaking based on yalls testing recommendations so ordered that and some new gaskets for intake manifold and head gasket - engine needs good cleaning so going to clean and replace those.

 

If your carb has a 12 volt heater coil, the S terminal will not provide enough voltage to fully open it. If you adjust it to be open, then it won't close enough for cold starts. You can use the S terminal or the coil positive wire as a trigger to a simple relay to give you fused 12 volts right from the solenoid/battery. Heater coil/springs are available for the S terminal - some factory cars used these coils. I don't think you can tell by looking but the carb installation info may indicate what voltage it is set up for.

Here is a link that helps explain the voltages - https://www.vintage-mustang.com/thre...stator.856554/