Cleaning Fuel Injectors on 2000 Ranger

[wiltat2]

Is there a way to clean the injectors your self other than those fuel additives?
I have a plug (rear passenger side) that gets to hot and breaks (Boch Platinum 4) and the dealer wanted 500 dollars to replace the plugs with stock plugs ($125) Clean the injectors ($200) reprogram the computer ($70) Oil change & diagnostic ($94).
I stopped them with the oil change and diagnostic. Bought a new plug to replace the broken one, added injector cleaner to the fuel, and disconnected the ground lead from the battery for 15 min., started it up and it ran fine for 2 days. Then the new plug broke. So it is parked until I can figure out a way to clean the injectors.
Any help out there?
Sorry for the long post.

[Autotech]

I don't want to make any assumptions about what your dealer is reccomending, some of your terminology is a bit vague, and I'm not intimately familier with your particular engine, so I'll start at the beginning.

When you speak of a plug "breaking" I have to assume you have a situation where the plug insulator is actually fracturing, leading to a misfire. The two causes for this are mechanical interference (which I'm hoping the dealer ruled out) and extremely high combustion temperature, usually due to a lean mixture. This physical damage is caused by severe detonation in the cylinder - so keep in mind that the rest of that cylinder is also being beaten to death.

I have to also assume the dealer took the time to eliminate the most likely cause of a single lean cylinder - some kind of vacuum leak. Frequently the cylinders at the rear of the engine have vacuum ports located on them (because they are at the rear, close to the dash, it is a convenient location) and if one of the hoses or accessories attatched to a this port is leaking that particular cylinder will be very lean.

If the proper amount of air is reaching the cylinder, the next suspect is fuel. If there isn't enough fuel the mixture will be lean. Not enough fuel through an injector can be caused by low pressure, incorrect injector operation, or a clogged injector. Low pressure usually affects all cylinders, but in some cases I have seen where the injector farthest from the fuel inlet to the fuel rail goes lean because all the other injectoers have already taken fuel from the rail. Incorrect injector operation may be caused by a defective injector or a bad signal from the PCM. And poor flow through the injector is pretty self explanatory.

As far as your dealers diagnosis/reccomendation it seems to be headed in the right direction. They are reccomending reinstalling O.E. plugs to assure that your aftermarket plugs aren't contributing to a marginal temperature situation in that cylinder. Many "high performance" aftermarket plugs tend to run hotter than there specified heat range (I learned this from direct personal experience). They are reccomending cleaning the injectors as opposed to replacing the suspect one, or the set. This decision is usually based on local variables like what they see in other vehicles, your mileage, and how successful the cleaning has been for other similar problems. Where I work we do not do in car cleaning - we remove the injectors and send them out. They are then tested, cleaned, and flow matched - if there is a substantial variation in flow we replace them. The computer reprogram they are talking about is most likely NOT simply clearing the faults and stored adaptations (what disconnecting the battery MIGHT do), but instead updating the operating software in the PCM, quit possibly with a different fuel/ignition map specifically designed to deal with your problem. This would be outlined in a relevant Technical Service Bulletin, which they will show you if you ask.

My personal reccomendation would be to ask specifically what the injector service consists of, and if it includes flow matching the injectors have it done. I would also have the reprogram done. If you want to save a few dollars, install the correct O.E. plugs yourself, and save the aftermarket ones to reinstall once you are sure the problem has been resolved.

Wordy and long, but hope it helps

Gregg

[wiltat2]

Thanks for your responce. The vehicle only has 53,000 miles on it. That seams to me like very low milage for injector problems. My 1990 F150 (EFI) has 147,000 miles and has never had an injector problem, and I fill them both up at the same pumps.
You are correct that the insulator is fracturing leading to misfiring.
Prior to changing the plugs at 50,000 it started misfiring, then it ran fine until it sat for 5 days while I was out of town.
I can get a new set of OEM injectors on the internet for $199 plus $11 shipping.
I found a Injector cleaning kit on the net but it was $237 and I'm not sure that it would have the proper adapter for my vehicle so that would additional cost.
I am going to replace the plugs with Autolite of the same value as original. And check for vacume leaks.
Thanks again for you responce.