fuel injector question

[kinyo]

mga bossing,

yung fuel injector ng civic esi 95 ... repairable ba ito? ibig kong sabihin, baklasable ba ito para malinisan yung mekanismo nya sa loob? palagay ko, hindi ito repairable, pero paki-confirm lang ... baka naman mali ako (sana!)

hindi ko pa natanong sa honda, pero baka alam nyo kung magkano ito, paki-banggit na rin ...

kung meron kayong experience sa injector repair, paki-kuwento na rin ... maraming salamat!

[artpogi]

sigurado ba na sa fuel injector mismo ang diperensya.

AFAIK fuel injector itself cannot be repaired, but it can be cleaned.

[kinyo]

Might be long story, artpogi, but here it is anyway ...

My car isn't used for a long time now, 3 months na siguro na nasa garahe lang. All this time, I routinely warm-up almost everyday to keep it in shape. Two weeks ago, I missed 3 days and found the battery discharged. The battery is barely a year old, always topped with water, but when it was only a month old, I deliberately deep-discharged it when my alternator broke while driving at the NLEX going home north, gabi nun, yet i managed to travel a hundred km with only park lights on, a/c and stereo are off. The car stopped itself in Camiling, Tarlac, just about 50 km from home so it didn't take long for my rescue to arrive. I guess nag-manifest na yung damage sa battery, medyo weak na sya, judging from hydrometer readings.

I then decided to install a home-made trickle charger for the battery so that warm-up intervals can be longer than 3 days. Also worried about wheel bearings, I elevated the car to rest on hollow blocks. Car was raised only about more than an inch so the wheels are still in firm contact with the ground, but I figured the pressure on the bearings are already reduced considerably. Nag-work naman yung charger and car started after 5 days. The car idled ok for some 30 seconds and then it suddenly rough idled. I tried revving but it didn't fix the problem.

So I started troubleshooting, although suspicious na ako sa injectors (baka sticky na), I did the quicker checks first by testing for high-voltage pulses on spark plugs. Meron namang pulses, dinig ko yung spark kapag binubunot ko yung hv cables. The sound is coming from the spark caused by the hv discharging on the engine body when the cable is lifted off the sparkplug. But i noticed that pulling cable numbers 2 or 3 don't seem to affect much the already rough idle! Kapag yung 1 or 4 ang bunutin, lalong lumalala ang rough idle, halatang-halata ang pagbabago. Next suspect are the injectors. So i pulled out my stethoscope (i'm not a doctor but i have a medical stethoscope for troubleshooting noise problems hehe) and started poking around the injector body, one by one. True enough, injectors 2 and 3 sounded differently from injectors 1 and 4. Injectors 1 & 4 sounded like snappy "tik-tik-tik" but 2 & 3 sounded like an almost quiet "tsik-tsik-tsik". With this observation, I concluded that I have injector/s problem, they are probably dirty or have really worn-out due to age, they have to be opened for cleaning or replaced entirely. But I didn't stop the troubleshooting process, I wanted to make sure that the injector drive signals coming from the ECU are ok.

I stopped the engine, pulled out my oscilloscope, find myself a needle, and setup everything for some true-blue electronic troubleshooting that I'm used to. Restarted the car, still rough idling, and checked for signals at the injector wires with the needle. Found all signals to be normal. But during the time that I was poking around with the needle, whoa!, the engine went back to its normal smooth idling! Did I have a bad contact somewhere or what? I tried wiggling the connectors, sometimes the engine would respond but more often it just idles normally. Hindi ko mabunot yung mga connectors for visual inspection and cleaning. I'm afraid I might break something because it is not easy to unlock it. Kita ko naman yung lock/latch pero I think some kind of tool is need to unlock it so reremedyohan ko muna, I don't want to have a broken connector/cover, otherwise madali nang pasukin ng tubig kapag nagpa-engine wash. Connector removal would also give me the opportunity to check for injector coil resistance. The coil resistance can be checked in-circuit with needles, of course, but I opted not to do it because the possibilty of damaging the ECU exists, most likely due to carelessness, kahit na alam kong hindi sisirain ng ohmmeter yung ECU with such test. For now, I believe resistance readings would be normal anyway because the injectors are working normally again.

That's it. I think the two injectors acted up and although the engine returned to its normal idle on its own, the problem is likely to show up again considering that the car is not used regularly. I have observed a not-so-rough idling before, hindi ko lang pinansin, but now I think that may have been caused by only one injector that was acting up. Siguro nga sticky/dirty lang yung mga injectors but eventually cleaned themselves after prolonged operation. I now intend to use an injector cleaning additive to see what happens. I did pour a can of injector cleaner long time ago.

Ano ba magandang injector cleaner? Impression ko kasi, pare-pareho lang sila, so I'm inclined to use the cheapest.