Hi There,

I'm wondering if anyone can tell me what the spark plug gap ratio is for a 1999 XLT Ranger, 4.0 Litre, 6 cyl, 4WD. I know very little about engines...I'm a single mom and I can't afford to go get a professional tuneup right now. I'll have to do it myself. Also, I just moved from an elevation of 8500 feet to sea level and now my truck is using ALOT of gas. Any ideas why it's doing that? Strawberry

 

First, welcome to FTE!!!

I have heard of spark plug gap, but never spark plug gap ratio. Can you explain what you mean??

 

I think she's after the plug gap, which I can't help with. I can say my truck used lots of gas untill I added a locking gas cap. Seems the neighbors were getting ten gallons a week or so for a while.

For more answers to your Ranger questions, try the Ranger forum on this site:
https://www.ford-trucks.com/forums/f...splay.php?f=35

One of the newest posts is about mileage that you may fund helpful. Good luck! And welcome to ford-trucks.com!!

 

Thanks for the replies....I did find that plug gap on this site. I want to know what my truck needs to get better mileage. I haven't tuned it up in over a year. The last time it was tuned I was living in Colorado at an elevation of 8500 feet, now I live at sea level in California. I know so little about engines I don't even know if my truck has a carburater, or if the elevation is a factor on this particular engine...again, it's a 99 Ford Ranger XLT, 4.0 litre, 6 cylinder, 4 wheel drive truck. I'm already keeping the tire pressure right, replacing the air filter, oil and the plugs. What else can I do? Does it need tuning to accommodate the lack of altitude here? There is more oxygen at sea level than there is at 8500 feet. Does anyone know? If altitude makes a difference then my truck is still tuned for 8500 feet at the moment.

 

You are correct, there is more oxygen at sea level. With the sensors and PCM, it will adjust to different altitudes, you do not have to re-tune for different altitudes.

 

You might try the old trick of disconnecting the negative battery cable for about five minutes and then reconnecting. Sometimes the computer gets stuck on the old high elevation settings and won't reset. So try it and drive it around and see if there is any difference. The vehicle is completely computer controlled and if all sensors are operating properly should readjust to the local altitude.

 

Hi Stawberry,
You should never need a tune up with an electronic engine like modern cars have; it's usually a myth put about by shops to squirt a few drops of throttle body cleaner about the place and generally keep the shop junior busy tinkering with things like tire pressures and minor maintenance items (that they SHOULD be doing at a service anyway)... for which they charge big bucks sometimes!
There are NO tuning adjustments they can make to your engine in a "tune up" so beware, don't be ripped off.
Coming here for advice is a good start.
Your engine will compensate itself for the difference in altitude but there is one other sensor in the intake that MIGHT cause your truck to run rich, at least in theory. It's called the MAF sensor (note: not the MAP sensor) and there are instructions on getting to clean it if you do a forum search here. It's easy to get to and easy to clean (but VERY fragile); the only real snag is the special tool required to unscrew it frm the intake, which is a "security torx" type. You might consider buying a cheap set of these drivers, in fact if you aim to do other work on your truck then you'll probablly need them again at some point. That's your call.
Anyway, as well as altitude making a difference to the air density (and therefore available oxygen to burn the fuel), so does temperature. The MAF regulates the air based on temperature but it can can get gunked up with oil and stop working properly which is why you sometimes have to clean it.
The other possibility that corsses my mind os that, at the lower elevation with more air pressure your car might just be making more power, period.
If you use that power, you'll incur a fuel penalty.
So did you notice that the vehicle is snappier round town? if so, just try taking it a little easier and you might be surprised!
Good luck, let us know how you get along.