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Hi Dick,
It's been a long time since I contacted you. This is regarding my "66 Mustang, 289.
When I'm accelerating onto the freeway my car hesitates, stumbling at around 50 mph up to 65 mph. It's ok putting around town. I sprayed some carb cleaner in the throttle already. I remember awhile back when a brake shop mechanic said I might need an accelerator pump. Is that the same as a fuel pump? I definately don't have the same power on the freeway as I used to have. A few days ago I had my doubts about making it home on the freeway. Eventually I will have to get new valve guides because of smoke on start up, but it burns off quickly so I'll wait on that. Does this hesitating on acceleration sound like a fuel pump? If so, what do those usually run so I don't get ripped off? Could it be valves at all?
Thanks,
Linda
Answer -
Well, hello again. Glad to hear you are still driving your dad's car!
If your hesitation is ONLY during initial tromping on the accelerator pedal, and after waiting a few seconds the power comes back on, that is an accelerator pump diaphragm in the carburetor (not the fuel pump - that's a different critter). The repair of this is quite simple, but you'll have to get someone who knows carburetors to do it, or if you're brave, I can coach you through it.
If, on the other hand, the car seems to bog down after you have been accelerating for a few seconds normally, and is seriously down on power at high speeds, to where you feel worry about going up a long hill, this is probably a fuel insufficiency. There is no reason to blame the fuel pump - before you have that changed (they cost around $20 but they'll get you probably twice that for the labor - and you can do it yourself if you dont' mind standing on your head for a half hour and getting grease up to your eyebrows).
BUT! = = = The first thing to do is to change the fuel filter - if that doesn't cure it, go ahead and get a new fuel pump, and be sure to replace ALL the rubber hoses in the fuel system at the same time - it is possible that these are still the originals, and they cannot tolerate the new oxygenated fuels. You can look at the label on the rubber fuel hoses - they have a code on them something like SAE 30R5 - it's that last number that is important. You need at least 30R7 to tolerate modern fuels.
OK, good luck.
Dick.
Dick,
Thanks for your reply. I already changed the fuel filter last summer or Fall. After I first start the car it sometimes dies, I have to hold the accelerator after it's started, otherwise as soon as I put the car in reverse it'll die. After I've driven it doesn't die. I've already fiddled with the idle and mixture.
Driving around town is no problem with power. But when driving on the freeway I have a reduction of power over 50 mph, and it stays that way, hestitating as I drive along, worse if going up a grade. So, does this sound like the fuel pump instead of the accelerator pump? or both?
If I need a new fuel pump does the gas tank need to be empty?
I don't think I can do the work myself, after all, I'm not a mechanic.
Thanks,
Linda
Answer -
Yes, this is a fuel pump problem, or possibly a failure of the rubber hoses or fuel lines.
I know you're not a mechanic, but I thought maybe you'd like to learn?!?. OK, forget that.
As an aside, my daughter does all her own mechanical work, while her husband is the caretaker of the kids - so gender isn't the determinant!
Anyway, have your mechanic install a new pump, and ask him to carefully inspect the fuel lines while he is at it, including those back at the tank.
It does not matter how much gas is in the tank, the pump is above the level of the tank bottom, unless the car is parked with it's nose way down.
Depending on the failure mode of the fuel pump, it is possible that the oil in the engine has become contaminated by gas. Your mention of smoking during start-up makes me think you should smell your oil dipstick (Ewwww!) or have your mechanic do that. If there is any odor of gasoline on the dipstick, immediately change the oil and oil filter before serious damage is done to the engine.
Attend to these things right away - this could be serious (and dangerous) if gas is leaking into the engine via a failed fuel pump.
Dick.
Dick,
I called a garage that works mainly on Mustangs (but will call a few others too). The guy said it was $42.50 to diagnose the problem, which would be applied to any work done. (He mentioned $20 for a fuel pump, and $85 labor.) He says it could also be a clogged fuel filter located at the tank, or a hose, plus the other stuff you mentioned. I knew about the fuel filter at the carb, but didn't know there was a second one.
I didn't notice any funny smell in the oil, but had it changed anyway since it was due. By the way, how many grease fittings are on a Mustang? I had a lube with the oil change and it still squeaks, I was wondering if one was overlooked. They said there were only 4.
Thanks,
Linda
Answer -
I don't know how many grease fittings are on a Mustang, but your owner's manual should tell you. It really doesn't matter in this case, because you should take it back to the lube shop and tell them there is still a squeak - it's their job to track it down. (It is possible that something is worn out, but after all the front end work you had done, I hope that isn't the case!).
The fuel pump at $20 and the $85 for labor is probably fair for your area. I think you've already diagnosed it, but if he is going to credit back the diagnosis charge to the labor, I guess it is a moot point.
There is probably a "sock" around the pickup tube inside the tank - that is a sort of filter, but if he is going to go inside there and look, there will be more labor involved. I'd just have him replace the fuel pump, any other filter that is in the fuel lines, and of course replace all the rubber fuel lines with modern rubber hose. If that doesn't cure the problem, then you'll have to have the tank investigated, I suppose. I'm betting that the fuel pump is the answer.
Dick.
Dick,
Is the "sock" around the pickup tube the same as the mesh filter on the fuel sending unit for the gas guage? I had a new one put on awhile back. I checked in my Mustang parts cataloge and there is some type on filter by the gas tank. I spoke to a Mustang Repair shop (but will consult with other shops first). I hope the $42.50 diagnostic doesn't consist of just a drive on the freeway. I read in my shop manual that there are some tests that can be done on the fuel pump while it is still attached.
Another problem is that when I first start the car for the day and it is idling ok, as soon as I put the car in reverse to back out without pressing
the gas pedal, it dies. The only way to prevent it from dying is to immediately press on the gas when in reverse. This makes me wonder if if it's the accellerator at the carb.
I have all of my paper work for work done on the car, so I'll check how many zerk fittings I had installed, regarding the squeak problem. The oil changers aren't mechanics and mighthave missed something.
There are so many flakey mechanics that I dread going into a shop, but as usual, I'll have to take my chances and try to pick one who doesn't act too shifty or condesending. (I could never get away with their behavior in the travel industry, but I wouldn't do it anyway.)
Thanks,
Linda
Answer -
Yes, the "sock" is the mesh filter on the pickup. Do you recall why they had to change it? Reason I ask is if the reason was it was plugged with crud, that might have happened again, due to more stuff in the tank. If that is the case, you are going to have to have the tank removed and cleaned out. If the parts book refers to a seperate gas filter back by the tank (not the mesh sock type filter inside the tank), then yes, I would definitly have that changed, if the fuel pump replacement doesn't fix your problem.
If I were you, given all the history of the situation, I'd simply go in and tell the man to put on a new fuel pump. If it hasn't been replaced in the last 5 years, its due anyway. Tell him to forget the "diagnosis", just put on a new pump! I'm guessing that will cure your high speed driving problem.
Your starting/stalling problem is totally independent. Your automatic choke is not set right - and probably it is just sticking in the bore of the air horn (the top part of the carburetor). I know you don't want to get involved, but if you can get the air cleaner off (one wing nut!), you can see the problem for yourself. When the engine has not been driven overnight, the flap on the top of the front half of the carburetor should be closed. To see this, remove the air cleaner, then tap the accelerator pedal one time to "set the choke", and look at the top of the carburetor. If you see the front half closed over by a metal flap, the choke is closing OK, and you need to have someone check the "fast idle" setting on the choke linkage.
If I'm guessing right here, though, you are going to find that the choke flap is not closed when it should be. The cure for this is to go to your local friendly auto parts place and get some "choke and carburetor spray cleaner". It comes in a spray can with a spray tube -just like a WD-40 can. Put the nozzle (tube) on it and soak the pivot axle that the flap turns on (if you hold the accelerator pedal down with a brick, this flap should move freely through its whole range of motion, from vertical (totally open) to nearly horizontal (closed) with no binding or friction at all. When you squirt everything that moves in the linkage on both sides of the carburetor, and manually wiggle the flap to work in the cleaner, it should begin to work freely. I'm betting that will cure your starting/stalling problem.
If not, post another question to me and I'll try again. Somehow, I expect to hear from you again!
Dick.
Dick,
I had a new Fuel Sender unit put on the car only because the gas guage wasn't reading the level, because the float wasn't working. But the car ran fine back then. I sure do miss those old days, before they messed with my brakes, alignment ,and the carb.
I've already used the Carb cleaner. Every once in awhile I do that.
I also filled up the tank with premium yesterday, and added some fuel system cleaner to the tank. I figured maybe the higher octane fuel might help. I'll see if a neighbor can help with holding down the gas while I spray the cleaner into the carb. I'll see how much I can fix myself before I take the car in. (I'm really not afraid of a little grease, especially if I can avoid getting ripped off.)
As you mentioned before that the fuel pump is above the tank, does that mean that the tank will not have to be emptied in order to put a new fuel pump on? Should i still have them check it out to see if it's really the fuel pump, or just put one on?
Thanks,
Linda
AnswerYou can just put a brick on the accelerator pedal to free up and clean the choke linkage (this is done with the engine off, of course!).
Premium gas is a waste of money, unless your car is tuned for it, (if it is, the engine will ping on acceleration when you use lesser fuel), but it will do no good at all for the other symptoms you are reporting. Save your money. The fuel system cleaner is similarly a waste of money, in my opinion, but if it makes you feel good, I don't think it can do any harm.
The fuel pump can be changed without draining the tank, yes. And yes, at this point, I would just ask them to put a new fuel pump on it, and don't get into the "diagnosis" bit with them.
Be sure to tell them to replace any old rubber fuel line hose - the original hose in your car cannot tolerate modern fuels, and could possibly be contributing to your problem as it will soften, crack and flake off pieces in the new fuels. The fuel line hoses must be stamped SAE-30R7 (or some higher number) to be safe to use today.
When you replaced the fuel sender, any crud in the tank would have come to light then; the mechanic would have told you about it. Relax on that subject.
Dick
