My '02 4.2l w/ 110k miles (manual transmission) runs like crap -- started to back-fire once in a while a couple of weeks ago and now chugs and spits when I slightly accelerate. It runs smoothly crusing at 70 mph. No engine codes are showing.

I've looked online for a website that will tell me how to do everything right on a tune-up, but am not having much success.

My wife is convinced that I'll break something and it will cost thousands to get fixed. So, can you guys save my ego here?

I need help something like: "Ok, moron, the first thing you do is this..., you get these parts....., etc."

I know absolutely nothing about what to replace and what tools it takes to do it. I've replaced an air filter before without hurting myself, but I'm basically clueless on doing a real tune-up the right way with the right parts.

And, if you don't want to call me "Moron", you can say "Bonehead"...

 

It is all good buddy. no one is a moron here. If you don't have the mechanical skills, don't beat yourself up over it. Some have it, some don't. Don't be afraid to spend a few bucks to take it to a dealer to get it diagnosed. It will cost you, but it will keep your ride running right. But if you are curious and want to try to make things better, then take the rubber tube off of the throttle body and clean the throttle body. There are cleaners there to clean things up. That helps most of the ideling problems. Another thing to change is the O2 sensors. They are supposed to be changed at about 60,000 I think. That will make a big difference. I am assuming you have changed the spark plugs and wires? You describe a lean condition with the backfireing. Have you always used a top tier gasoline? I only run shell. It makes a big difference with engine cleanliness. Also, have you changed the fuel filter? That will make a lean condition. If you buy gas at a low volume gas station, you will have sediment problems. I have 71,000 miles on my focus and never changed the filter... but I go to high volume stations. As they say.. your milage may vary. these are the simple things to check. A trip to the dealer isn't a bad investment. Your truck should do 3-400,000 miles easy if you maintain it.

Oh.. and welcome to the best F-150 site on the internet. Enjoy

 

I don't want to sound like an *** but if you have trouble with the air filter then you should let someone a little bit more compitent take a look at your truck. I would advise against the dealer as you will get raped by their prices. Somethings that should be done plugs, wires, and fuel filter for sure. If you have a friend that is mechanically inclined maybe ask him to help you out and teach you how do some of the basic tune up procedures.

 

Thanks Chris.

Can I use carb cleaner to clean the throttle body? Just hose it down with the cleaner and wipe it off?

I haven't changed the spark plugs/wires. The boot just pulls off? I know I need to changed them one-by-one so I don't screw up the firing. What are the best plugs? Is the best wiring a special brand? Should I go to NAPA or Autozone or does it really matter?

I get gas at Wal-Mart...it probably comes from China.

I want to put in good parts but not spend a fortune. I would rather try to do this myself rather than take it to a dealer.

 

First thing, see if you can locate a Haynes or Chilton manual for your vehicle. Autopepadvancedzone should have one. Will tell you how to do much on your truck, with pictures too. Then you can ask more specific questions here.

Good on you for wanting to learn and do it yourself.

 

At 110k, if the plugs have never been changed, it's overdue. Get a set of OEM Motorcraft Platinums, and I'd also recommend a new set of OEM Motorcraft plug wires. The hardest part is getting behind the engine to remove the old wires going to the driver's side (the coil pack is on top of the passenger side valve cover) from the clips and route the new ones. Use dielectric grease in the boots at both ends of the wires. If it still runs like doo-doo, you may need a new coil pack.

With all this said, you could take it to the dealer and get a full diagnosis for about 80 bucks. Last summer, I did exactly that because mine was misfiring - 82k miles. New plugs, wires, labor, a BG intake cleaning job, and diagnosis cost me $573. If the coil is shot, add another $150 parts and labor to that. The diagnostics and BG job were menu priced and the labor rate here for everything else is $76.95 an hour. Also expect to be sold a fuel filter and air filter if you haven't changed those recently.

 

Thanks all for your sound advice.

 

. . .

 

Buzz, a 4.2 V6 does not have a distributor, therefore no distributor cap or rotor. It has an electronically triggered 6 post coil pack on the passenger side valve cover. Quality wires are a lot more than 30 bucks. Factory plugs are platinum and should be used, recommended change interval is 100k but they don't always last that long. PCV valves are more than $5 and do not need to be changed unless they go bad (rare). There is no breather filter.

 

glc forgot to mention that no tools are required to "break" the fuel line. LMAO

OP, a Haynes manual will help you in this situation tremendously. Even those of us with experience still have to go back to the book now and then, for something or other.

 

Well, I give him the benefit of the doubt there - I think he means "disconnect".

 

Well, I changed out the plugs,wires, air filter, fuel filter, and changed the oil/filter -- - took me a good 3 hours, and nobody died! The truck runs well, with no hesitation, but had a small backfire. All in all, I'd call the experience a success. So, thanks for your help.

In the next couple of weeks, maybe I'll tackle the O2 sensors and clean the throttle body.