what's the deal with injectors?

[HoffaLives]

a local shop wants a min of $65.00 to test and clean. people say that cleaning and disassembly isn't a diy job. searching on the net i can't find any info. i know the jet holes are tiny, but what's so hard about cleaning them? i'm used to doing my own work, so if someone has any experience in this line can they tell me why i can't clean em myself?

[ekotopia]

I beleive it has to do with adjusting them to the right opening and closing preassure.
Cheers

[billangiep]

and also I assume checking spray patterns...

[HoffaLives]

but that is just testing, not actually cleaning. the adjustments are made by adding extra shims if the injector doesn't break at the right pressure.
i just wanna clean his guys cause i know at least one of 'em is dirty with a wonky spray pattern.

[erps]

I worked as a diesel mechanic for a few years a long time ago. We sent the injectors out to an injector shop, so I never tried it myself. Why not examine the tip under a magnifying glass to see if any of the holes are worn or plugged up with carbon? Then you can decide whether to clean it yourself or send it out to someone who knows what they're doing.

[Faster]

A good diesel mechanic once described a routine to me (that we have yet to try..) of temporarily running the engine from a beaker of injector cleaner (sorry, don't know the brand/type) periodically to keep the injectors clean.

Sounds like something like this might clear up your partially plugged injector.

I wouldn't mess with this too much, a really screwed up injector can do damage with a wet spray, it causes a knock that you'd swear was mechanical contact. A couple of hundred bucks is not a lot of boat units for peace of mind.

[capngregg]

Actually $65.00 is a good price (4, 6, 8 ?) no matter how many you have. The materials are rather inexpensive (diluted sodium hydroxide of around 10 ph if the injector bodies are stainless steel) and a heated ultrasonic cleaner. Flowing fuel (or some type of calibration fluid) through them is the trickier part. The flow after clean process ensures the cleaning fluid is flushed from the interior chambers of the injector and it flushes any loosened fuel varnishes from the internal components.

IMHO it is not cost effective to set up to do certain jobs especially when they involve chemicals and procedures that can be dangerous. Many shops that do the cleaning will perform a before and after pattern test and a flow volumn check (all nicely computer printed) along with a report stating the condition of the components.

I am completely with you on wanting DIY but this is a good one to leave to the pros that are tooled up to do the job. Calibration may be recommended on some units but more than likely the injectors will be performing within book specs after cleaning.

Good Luck!

[HoffaLives]

Originally Posted by capngregg

I am completely with you on wanting DIY but this is a good one to leave to the pros that are tooled up to do the job. Calibration may be recommended on some units but more than likely the injectors will be performing within book specs after cleaning.

Good Luck!

phooey, i was afraid someone would say this. i really, really hate to farm stuff out to others. but yeah, sometimes it ain't worth the headache. i have spent hours doing something a guy with the right tools could do in ten minutes (and $100.00).
i was just hoping there was something i hadn't heard of.

seems to me there was a time when a guy had to do all his own work. i guess those days were simpler.

[hellosailor]

hoffa, the factory manual for my car actually says that if the special service tools aren't available, you can stick the injector in a jelly jar or mason jar and watch the spray pattern to see if it is even, then measure how much gasoline it shot in one minute to check the flow rate. And, that with fuel vapors you can also blow yourself up very easily.

With diesel injectors the pressure should be much higher--there's a real risk on injecting diesel into your body. So if you don't want to screw around with jelly jars, there are special machines they put the injectors into ($$) which show flow rates & let you observe patterns safely. Then there's the cleaning and adjustment--if any is needed. I think the cheapest net price I ever saw was 20-odd dollars a piece, so $65 for at least two injectors is not unreasonable.

What would it cost you to buy two new injectors (assuming it is two you need) and then take your time screwing around with the two you have? If it works, you have a spare set that you can swap in right away if the running set clog or fail--and that's worth something too.

Running a cleaning solvent though them for any length of time assumes you have a PUMP of some kind and can jerry-rig a jig to connect them to it, so you can flush them through. That's gotta cost something, surely you don't want to pump cleaning solutions through the high pressure pump and engine systems itself?

[cardiacpaul]

not to mention if something is wallowing around inside the injector and decides it'd like to make its way out, blowing part of the tip off into the combustion chamber.
I'm thinking that wouldn't be good. Let the guys that make the big bucks do this one.