Fuel delivery problems, I think.

[19stang66]

I went to pick up my car from my storage place and when I started her up she wasn't running as good as when I parked her two days before. Like it wouldn't stay running unless you keep on the throttle or are actually moving at a decent speed, above 10mph. It ran perfect before I parked it so it shouldn't an idle problem. I noticed the clear glass fuel filter I have that is before and after the fuel pump were pretty dirty. So I replaced them in the NAPA parking lot this afternoon. Now it runs even worse.

I can't accelerate from a stop or from a 20mph roll without bogging down. It just stumbles horribly and almost dies unless I let off the throttle. I didn't replace the fuel pump since it's still pretty new and I don't see why that would clog since my filter would have clogged with crap first, which it did. What now??? There is a big car show tomorrow that I'd like to go to so please help!!!!!

I just tuned it and had it running great. I got my mpg up from 9 to 17-18 and the power is better. I have the Pertronix ignition and coil with 12v. I have brand new plugs and they are buring a light grey and the plug wires are only a few years old and are in great shape.

 

[D.Hearne]

Is there water in the fuel ?

 

[19stang66]

how would I know? There is a lot of condensation build up at the end of my tailpipes that I've never noticed before...

 

[19stang66]

Just put in the new fuel pump and that didn't help at all. I checked the jets to see if they were clogged and they were fine. Could it be bad gas? I put in a new tank the day I parked it. I can't drain the tank that easily since there isn't a plug. Is there an additive I use to help burn up this tank of gas? Seafoam??

 

[izzy jr]

you could check to see if it's the gas by disconnecting the fuel line from the hardline inside the engine bay, use a piece of fuel hose connected to you clear fuel filter and drop into a gas can sitting outside the car, pour alittle gas into the carb to make sure it's primed and start it up and see if it runs any better.

 

[jcode68]

A friend recently had a problem with his 67 where he would run into a fuel starvation problem after running a short period of time. We ended up determining that the gas cap he had was not vented, causing the fuel pump to be unable to deliver fuel once the vacuum pressure reached a certain point in the tank. His tak was newly replaced by the previous owner. The top of his tank had actually collapsed in one area because of this problem. Just for kicks, take your gas cap off and see if it runs any better. If it does, this could be your problem as well.

 

[D.Hearne]

Drain the fuel from the carb into a clear container, if there's water in it, you'll see it. Gas and water don't mix. If you have water in the fuel and can't drain the tank, add pure alcohol to the tank, the alcohol will mix with the water and then burn.

 

[19stang66]

I could try the gas can trick. I do have a vented gas cap. I know this because my garage smells like gas all the time, but that's how these cars are supposed to smell, right?

 

[10secgoal]

Try taking out the idle mixture screws and blowing compressed air into them. Some times dirt clogs the idle circuit and you get leans stumbles. I find this problem ALOT with cars.

 

[19stang66]

You mean blow air into the carb where the idle screws were?

 

[Shakin66]

If it runs ok at higher RPM's but stumbles and wants to die at lower RPM's you may have a vacuum leak.

 

[TD68302]

Check your needle & seat, might have dirt in it, not letting it close and flooding out.

 

[19stang66]

Thanks for all of the suggestions guys. Since I'm working on my car in the parking lot behind my apartment I don't have a lot of tools. I'll try using some new gas from a gas can and see if that will work. I'll also put some gas in a clear container to see if I can see any water.

How would I check if I have a vacuum leak? Where can I find the needle and seat in a Holley 4160 vacuum secondary? Where can I get pure alcohol and how much would I need for the approx 10 gallons that are in the tank still?

 

[10secgoal]

You mean blow air into the carb where the idle screws were?

Exactly. Tiniest piece of dirt throws off the metered fuel leak.

 

[BarnStang]

You can get dry gas or some other additive at the parts store. If you have a 4160, the needle and seat should be on top the carb at the bowls. Look inside the top of the carb after you run it (then shut it off). Is it all wet in the front or back or both? Stuck needle seat will flood the carb. You can take the whole seat out of the carb with the bolws left in place and clean them out.
Vacume leak will be harder. Check that stuff first.
Oh, get some carb and choke spray and spray through the mixture screw openings if you don't have an air compressor handy. You can also spray down through the idle air bleeds on top the carb.

 

[19stang66]

Well I bought a thing of Seafoam to try in my gas tank and carb. I did what the instructions said an still no luck. I'm just going to have my brother come up here and tow her back home. She's being a bad girl and needs to think about what she has done.

 

[woodsnake]

"She's being a bad girl and needs to think about what she has done."