QuestionMy 2001 v6 Santa Fe is miss firing. The garage says all 6 injecters need replaced. Can I possibly do this myself or is there a way to clean them?
AnswerIf you can remove the intake plenum, you can replace the injectors yourself. The plenum is held on by about 7 bolts/nuts onto the intake and three bolts in the rear at the support brackets.
GM has a technical service bulletin which advises mixing about-- I'm recalling from memory, so quantities may not be exact-- 20% GM top engine cleaner with 80% gasoline. It'll need to be put in a pressurized apparatus then attached to the fuel supply line. The power will need to be disconnected from the fuel pump. The apparatus will need a pressure regulator on it to keep the pressure low enough to prevent returning the mixture to the fuel tank-- it can damage the pump and sending unit. I've done this with much better success than any other method of cleaning, but I'm doubting you'll be able to do this yourself.
Needing 6 injectors in an odd diagnosis. It's possible, but presumably there'd be a larger root cause. All six won't fail at the same time, but if there's something foreign in the tank, they could clog at the same time.
Has the garage checked the more common causes of misfire, such as wires, coil, and plugs?
Off the cuff, it sounds like the shop is guessing. If you think this could be the case, stop by and ask them to show you the problem. I'd expect them to have the plenum off already, since they've said it needs six injectors. If the plenum isn't off, how'd they determine the injectors were bad and the wires/plugs weren't? You cannot get to the rear plugs/wires/injectors without removing the plenum. Was your check engine lamp on? Ask them what trouble codes were stored. Misfire codes would be in the form P030x where x is the number of the misfiring cylinder. P0300 would indicate a random or multiple misfire. So, if you have a P0302 and no other codes, they should be able to explain why they're recommending six injectors instead of just the one in cylinder #2.
Lastly, I'll say that I've seen more problems with the injectors on this engine than any of the other engines Hyundai makes, but it's still much less frequent than plug wire failures. In all but one instance, the injector problems were clogging issues, and were only perceptible by humans when the car was cold. It ran just a little rough for a few minutes, and under throttle the problem was imperceptable. The computer would pick it up and set a check engine lamp indicating a misfire in the offending cylinder(s). Ignition misfires, on the other hand, tend to be worse under load and are almost always *very* obvious to the driver.
