I am having trouble with my 1999 Ford Expedition dying all the time now. Happens both when it is cold and warm. Mostly when the engine is cold and I am backing down the driveway. I have
85K on it, the 4.6L and it is maintained by Helfman Ford. Last year they replaced the spack plug wires and spark plugs due to "arcing".
Tonight it is 35 F outside, it died several times when I started it to go home from work. Then it died in the driveway into the garage (after a 5 mile drive, a first).
The last tank I ran in it was premium. I have learned not to go to a certain shell gas station since it's regular causes many of the same symptoms.
From the earlier "Throttle Positi I got in my 2000 Taurus SE Friday for the drive back from the coast (outside temp around 35°F and the car didn't want to start. It cranked just fine but acted like it wasn't getting any fuel. Once I started keeping my foot on the gas, it started but stalled if I let it just idle. It seemed to want to idle between 3-500 rpm; much slower than its normal
1100 cold and 700 warm. I just kept giving it gas while I changed gears from park to drive. It ran smoothly in cruise the whole way but continued to stall if I stopped at a light without keeping my foot on the gas. Finally, it seemed to start idling correctly after about 4 hours worth of mostly highway driving.
I'm curious what the problem is. Obviously, I've got to get it fixed but it's running OK right now. I don't expect that to last though...
This vehicle was designed for reg. unleaded, 87 octane. Premium can cause driveability problems, reduced economy, higher emissions, and a smaller bank balance.
I've been working on vehicles professionally for 30+ years.....and if I've heard it once I've heard it a thousand times. People say it a lot. True it's all in the heads of the people saying it, but it is a very common myth.
I cleaned mine about three months ago. Easy. Still working fine. Near as I can tell there's a shaft that gets a little dirty and starts sticking. The electrical part works fine once the shaft is cleaned. Two small bolts and a couple easy hoses. The other poster said he paid
268.00 to the dealer for the fix. After cleaning hit it one time lightly with wd-40.
cleaned. Two small bolts and a couple easy hoses. The
hit it one time lightly with wd-40.
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Cleaning an IAC is a very cheap alternative to replacement,But.. IMHE it is a hit or miss fix. I always clean them first. I've cleaned some and it didn't work, or only lasted a short time before sticking again. I've also cleaned some that were trouble free for years. Just be aware that it may not work and you'll have to spend the bucks. Tom
I think you need to make more careful calculations with regards to fuel economy. Unless there is something seriously wrong with your vehicle, there is no way you are getting 5 to 6 mpg better mileage just by using premium. I have owned two Expeditions. I ran extensive comparisons between regular and unleaded fuel with both and never got any measurable increase in fuel economy by using premium gas (or synthetic oil for that matter). In theory, you might get slightly better fuel economy since the PCM in the Expedition will readjust the timing when you use premium. Ford claimed an extra 5 to 10 HP and up to one half mile per gallon fuel economy improvement with the use of premium. A 5 miles per gallon increase is x-files territory.
You don't need premium gas. Most likely what you do need is a new IAC Valve. These clog up. When this happens, they can't adjust the air flow to maintain the idle and the truck dies. It is a common problem for later model Fords. The part is in the $100 to $130 range. A dealer will charge you $65 to $100 to diagnosis the problem and 1 hour or so of labor to replace it (actually in is a15 minute job). Figure on a dealer charging around $250 to $350 to fix the problem. If you are handy, the IAC is easy to remove and cleaning it often restores it to functionality.
You need to make more careful measurements and do the calculations over multiple tankfuls (at least three, five is better). I have compared premium and regular fuels for multiple vehicles (two Expeditions, a Mustang, an F150, and a Saturn). Not one got a statistically significant increase in fuel economy when using premium fuel. I was sure the Mustang would not, since it does not have a knock sensor, and therefore has no way to adjust for changes in gas quality. I did expect a slight increase in the case of the Expeditions. I was so disappointed that I actually ran premium for over
20,000 miles in the 1997 to try and detect a difference. I even disconnected the battery in an attempt to force the PCM to relearn the setting. None of this made any difference. At least in 1997, Ford did claim that you would get slightly more power if you ran premium. The PCM used by Expeditions is able to adjust engine parameters (mostly ignition timing) if premium fuel is used. This adjustment when premium fuel is used might (should) result in slightly better fuel economy. However I never could detect it despite extensive efforts to do so. Modern regular and premium fuel contain essentially the same energy content per gallon, so there is no reason to expect more than a minimal increase in fuel economy when changing fuel. Any increase would solely be related to improving the efficiency of the engine. Unless there is something seriously wrong with your engine, a 50% increase in fuel economy is simply not believable. I can assure you that if such an increase was possible Ford would require the use of premium fuel (and be completely justifiable in doing so). Ford struggles to meet CAFE restrictions. A 20% to 50% in fuel economy would be godsend.
If you still believe that you get 50% better fuel economy in your Expedition when running premium, why don't you think Ford requires the use of premium fuel?
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