Fuel System Stalling/Hesitating/WTF?

[johnunit]

gas tank does NOT need to be replaced. you have, unlike EFI cars, a fuel pump on the front of the engine. There is basically nothing to go wrong as far as fuel delivery in the tank itself.

This is a frustrating issue but throwing parts at it is not the solution.

[1987cp]

What John says. Throwing parts at a car at random is unlikely to solve anything. This is why we're asking questions about the overall condition of your fuel and ignition systems.


One good thing about carb systems is that most parts are very cheap. Pumps are about $20US. Filters are as cheap as $3 or $5 US. Pickup screen inside the tank was like $5US for a two-pack from Ford, as of a few years ago.


Don't overlook things like poor idle mixture, vacuum leaks, or a stuck needle-and-seat. You'll usually notice a fuel line problem because of the fuel puddle under the car. And even if the carb is FUBAR, you probably don't want to spend good money on another VV unless you have inspections and the goons are stricter than humanly imaginable.


Oh, and you do not know that your plugs look good just because they're a week old. If they're going to foul, it'll happen pretty quick.

[86VickyLX]

Okay, so today after coming back from a 2 hour drive or so on a hot day, I found the engine stalling/spluttering/I dunno what was going on at about 50KPH.

It was acting like there was intermittent fuel in the system as though I was about to run out of gas, only I'm not of course.

This happened once before, when I found the air filter was dirty as can be. Only the engine would do this at about 20KPH instead of 50KPH and it would actually stall out on me.

Putting it in Neutral and revving the engine produced black smoke from the exhaust.

Can anyone help me pseudo-diagnose the problem? I suspect fuel pump/carbeurator?

I found one time that water in the carb made it run completely funky. Was a 82 LTD with the 351 and the VV. The issue was basically shitty gas. Cleaning it out and reinstalling the carb with new gaskets made it run like new.

Also, just for some preventative maintenance, check out the pickup in the distributor. Also dealt with a random no start/stall. The ignition pickup was ancient, the wires were completely screwed, and the pickup was rocking back and forth. I'm not saying this is your problem, but this can cause you problems in the future.

[Mike_O]

I found one time that water in the carb made it run completely funky. Was a 82 LTD with the 351 and the VV. The issue was basically shitty gas. Cleaning it out and reinstalling the carb with new gaskets made it run like new.

Also, just for some preventative maintenance, check out the pickup in the distributor. Also dealt with a random no start/stall. The ignition pickup was ancient, the wires were completely screwed, and the pickup was rocking back and forth. I'm not saying this is your problem, but this can cause you problems in the future.

Well I had the fuel filter replaced, and found the front oil pan screw is leaking oil now.

So I figured I'll have the carbeurator rebuilt and do what some folks suggested here and have the vacuum lines inspected. Hopefully that will put an end to it.

Assuming the engine doesn't seize due to oil leaking of course.

[johnunit]

unless it's pouring I wouldn't worry about it. If you're worried, put a cup or something right under the dripping spot overnight. That'll help you gauge how much oil you're actually losing.

I have at least 4 separate oil leaks and the car will still not lose enough oil for it to show on the dipstick while sitting, even while being stored for the winter.

[Mike_O]

unless it's pouring I wouldn't worry about it. If you're worried, put a cup or something right under the dripping spot overnight. That'll help you gauge how much oil you're actually losing.

I have at least 4 separate oil leaks and the car will still not lose enough oil for it to show on the dipstick while sitting, even while being stored for the winter.

My biggest nightmare is to have the engine seize due to low oil pressure.

I get really, really nervous when it comes to oil leaks.

The mechanic dude said that the screw threads are stripped (somebody before me had done an oil change and damaged the screw or something), and he said he could rethread the oil pan to fit a bigger one.

Is this a good idea?

[1987cp]

Yes, paying good money to someone to rebuild your carburetor will definitely solve your problem.

Seriously, if all you're going to do is pay someone to do the first thing that comes into your head to do, why bother asking us anything?

[Mike_O]

Yes, paying good money to someone to rebuild your carburetor will definitely solve your problem.

Seriously, if all you're going to do is pay someone to do the first thing that comes into your head to do, why bother asking us anything?

Because I'm not a mechanic, and this is a forum of people who are fans of the type of vehicle I currently own?

If you feel you're wasting your time responding to my questions, feel free to discontinue doing so.

[79lincolnlover]

What grade of gasoline have you been buying? Regular gas isn't the best nowadays...You should try Extra or Supreme next time.

[Mike_O]

What grade of gasoline have you been buying? Regular gas isn't the best nowadays...You should try Extra or Supreme next time.

I've been sticking with 87 Octane. What benefits to going with a higher grade are there?

[johnunit]

1. rethreading the oil pan is doable and a good idea.


2. rebuilding the stock carbs on these thing is sort of a weird subject. They have both a poor reputation for reliability and a very difficult set of steps for being rebuilt, so you tend to find people swapping to other things (most commonly a Holley carburetor) instead of rebuilding them, and finding a local shop that can and will rebuild it competently is difficult. It will run you easily 200 dollars just for the actual rebuilding of the carb, installation, tuning, etc. aside.


3. In most parts of Canada, 87 and 89 octane contain ethanol. This is mildly corrosive and can cause damage to carburetor and fuel system parts. It eats away at many types of rubber and other compounds. Not such an issue for newer cars, but it can cause problems with carburetors. The high ethanol content can also cause hot fuel in the carb's bowl to boil off, which could be part of your problem. 91+ octane, at least here in Ontario, doesn't contain any ethanol (it should tell you on the pump) and thus doesn't have the corrosive or boiling issues.


I'm juggling a few similar threads in my head, so forgive me if you've done these things already but;

You should replace any of the following not known to be less than about 2 years old:

plugs
plug wires (get ford racing wires)
fuel filter
Air filter
cap AND rotor
PCV valve
breather filter



Then switch to 91 octane fuel, long enough that most of the fuel in the tank the 91 octane at least.

These are all things you'll want to do anyway, regardless of the specific problem. If these do not solve your problem, then you can get into the more expensive and complex stuff like servicing/replacing the carb itself, testing voltages on parts of the ignition system, etc.

Until the things that will need to be new anyway are new, there's no need to start replacing old parts that don't generally wear out or break.

It is very possible you have a carb problem, but in this situation that is about the most expensive possibility, so you want to eliminate all the easy/cheap/regular maintanence stuff before addressing that possibility.

[Mike_O]

"plugs
plug wires (get ford racing wires)
fuel filter
Air filter
cap AND rotor
PCV valve
breather filter"


Everything on that list except for the PCV valve have been replaced already.

I want to go to 91 Octane for the performance, but the higher octanes are more spark-resistant.


I aim to replace the following components de facto within the next year:
- power steering pump
- oil pump (can this be done?)
- fuel pump
- fuel tank & straps
- water pump
- idler and tensioner pulleys
- belts
- valve cover gaskets
- radiator
- heater core

[johnunit]

You don't have a tensioner of the sort that wears out. It just sort of gets pried tight then bolted there, no spring to weaken. The oil pump is a lot of time/money to change because you have to lift the entire engine if not remove it from the car.

The rest are good ideas.

[1990LTD]

oil pan needs to be off to do the pump....not normally a problem if you don't have a big crossmember going between the sumps of our oil pans. engine needs to be moved - at the very least lifted up a bit, if not removed completely.

[mrltd]

Good luck finding someone that can rebuild a VV correctly. Even 20 years ago that was nearly impossible to find.

Your mechanic won't rethread the pan, he'll just shove an oversize, self tapping drain plug in there. Which could easily rip off the little piece of metal that the plug actually screws into. This is good for the mechanic since he will now get to charge you to replace the oil pan. At least it's a good time to also replace the oil pump. And no offense, it's really quite tough to seize one of these motors. I ran a few with nearly 0 oil pressure HARD for quite some time.