808Bill

Most big name auto parts stores can send them out. NAPA had cleaned and rebuilt mine last year but I'm going to put new ones in soon.

SoCal911t

I plan on buying new injectors for the 996 but I've used an injector service for my '80s BMWs. The owner is great to work with and his prices are reasonable.

pdxmotorhead

I've used the guy up in I believe issaqua Washington,,, most big cities have a injector service company, its mandatory for most diesels and commercial rigs o keep their clean idle status.

I've also used 5-0 motorsports for my jeep ones a couple years ago.

I just googled around for injector cleaning services..

Mike Murphy

I thought Jake has mentioned at one point that many injector cleaning services aren’t always that great? That some injectors come back worse after cleaning, and for that reason, we should buy new?

bazhart

Unfortunately quite a few misunderstandings about these issues which can be cleared up if you would like to read a long detailed report about it from our years of research.

It is available free from admin@hartech.org.

Baz

Flat6 Innovations

These injectors can't be effective tested in a lab. The issues that we see are aggravated by engine temperature, especially when the engine is shut off, and fully heat soaked. When the engine shuts down, the engine will elevate in temperature for a few minutes before it starts to cool, all the while the injectors are being asked to hold at least 55 PSI of fuel pressure. With the engine shut off, the fuel within the rails and injectors also heats up, which makes it more difficult for the injectors to hold back.

Fuel leak down often occurs due to this, and the next time the engine is started, it does so with a puddle of fuel within the intake ports, or cylinders, if the intake valves were open on the cylinder at the crank position that engine shut down at.

In short, your lab tests mean nothing in regard to how the injectors function in the real world. We have seen injectors "test" perfectly, yet puddle fuel in the ports that was visible with a long reach bore scope down the intake runners, with the engine hot. During the testing the lab does not use hot fuel to test the injectors, nor do they have them fitted to a hot engine, in an engine bay that averages 140+ degrees F. The lab tests are done at ambient temperature.

This is why injector cleaning, and testing means nothing to me, and hasn't since these discoveries, which we now see all the time.

pdxmotorhead

Agree,, Cleaning the injectors wont bring a worn out one back, but if you have a rig that does not get used a lot,, "hanger queen"
having the injectors cleaned does help avoid varnish buildup and fuel sludge clogging it,, my theory and its not specific to
Porsche in the least is that a cleaning every other year and new maybe every 80 to 100 K will give you the best overall performance,
I've had enough brand new injectors that were DOA that I'm as concerned about where they are made, and their manufacturing
as I am whether they are brand new. Add yea if you take apart an injector,, you can see quickly that a true full rebuild ain't very likely..
They just are not made to come apart.. I have dismantled the early fat body EV-1 injectors and reassembled them, but that
was young me where time was free and money short..

I use a injection cleaner consistently,, I try and put it in the last tank before an oil change..
And do the change when the tank is almost empty.. I use techron for the most part.

On the road race cars I've worked,, we send the injectors out every season..
over the winter then pickle them with a light oil like a marvel or a marine fogging oil.
Of course we also have 2 or three sets in the tool box..

For the mechanical injection on the sprint cars, they are simple and get cleaned between
each race weekend.. Methanol is just so aggressive your in trouble if they sit..

Mike Mullins

I think in similar vein and practice the same. I do have very intermitant stumble of one or 2 random cylinders at idle,
I don't see anything on scans, so I need get out the Durametric and see if I see anything.
(I might need help but when I get some time..

Taca2360

Idle is sometimes unstable now and sometimes has a mini backfire . Any opinions would be much appreciated!
Thankyou

​​​​​​​https://youtube.com/shorts/9_utLacn6_I?si=hufx9hiMpXAfjXb9

pdxmotorhead

How old are your coil packs years count as well as miles. my 03 they were pretty baked at 116K miles when I replaced them...

Taca2360

Can’t remember if I changed the coil packs at some point . I changed the spark plugs probably 2k miles ago. Sometimes the car is left over a month without using it; obviously every time before starting it again I try not to push it and leave it there warming up making sure everything is as it should be. IMS was done at 78 k miles and currently has 98 k miles. I’m worried there’s a scoring on one cylinder I guess I’ll have to use a endoscope to see what’s going on .. There’s 2 things that have my head questioning me if it’s related or not one being the clutch release bearing because not long ago it started to make a heavy tick noise different from what you hear on video after riding and car hot sound is audible when clutch is released on idle, but if I engage the clutch sound (clack,clack) goes away . Second thing is the fuel filter I’m pretty sure that has never been done; making one injector to stick and give a little tick, hickup and misfire . But in other hand what we all worry about is if there’s a scoring on a cylinder ? Or probably a lifter or timing chain tensioner (many factors) that’s why I’m here 😌 to figure out with you experts to help me out based on your experiences what should I do first ? I guess I shouldn’t drive the car cause it’ll make it worst . If I drop the oil with a bore scored cilinder should I see small shavings ?

Thanks you and sorry for my English .

Car is located in Nicaragua

pdxmotorhead

You should drain the oil in to a perfectly clean pan and you might see a bit of metal with any motor,..
But to tell for sure the sump has to come off and do a bore scope... "Its the best way to be sure"

If you have changed the oil and don't have weepy injectors your odds go much lower down on odd of scoring..
Leaky injectors cause bore scoring in anything not just porsches.. The Boxer engine is just more sensitive to it.

DONT let a 996 sit and idle to warm up.. Start it, let it smooth out then drive away gently staying under 3000 rpm till it hits 180F
If you let them idle it takes too long to heat up the pistons, oil etc. .

If available in your area We have a product called Sea-Foam that is a marine engine fuel treatment. A half can in a fresh full tank of gas goes a long way to getting the varnish out of injectors. It forms when gas and oxygen meet without spark and sit around.. I use it in the last two tanks before I change the oil.

damage98MO

"If you let them idle it takes too long to heat up the pistons, oil etc."
I was told that Its not the time to heat up, it's the amount of fuel to air mixture. Just sitting at idle when the engine is cold, doesn't that mean more fuel that washing the cylinders? Also known as running rich...https://mechanics.stackexchange.com/...or%20starting.
​​​​​​The unburnt fuel washes the cylinders, preventing proper lube, and this results in more wear. ie. Bore scoring.
​​​​​​Get your car, any road car, moving once you've started it. At least you're getting some value for your money. I had neighbors who come out, or use remote start, and then have breakfast indoors with the truck running. In NC. It's not even below 30...Sigh. There's a lot wrong with that, but stupid is as stupid does. I'm not the enviro cops, so you know, live and let live. I believe that here in Canada, for years, most parking lots are no idle zones. I see signs all the time attempting to enforce that. But I've seen 1 LEO since moving back, and that one was parked at the digby RCMP. It's the wild West out there. Given the scarcity of law enforcement, I would imagine no idle laws are pretty dang low on the list of priorities. I'm rambling again. It's 'retiree syndrome' 💯🇨🇦❤️

Porschetech3

LMAO...no idle zones....That's a new one on me...never heard of that..Thank you !!!

Here in Bama we have a lot of "no wake zones" on the lakes near Marina's .docks, but I can't imagine them ever putting no idle signs in parking lots...

pdxmotorhead

I agree There are a ton of reasons NOT to idle a 996 to warm it up.. And almost no reason to do it.
Fueling, Engine warmup all part of a circle of proper care.. If your pistons don't get heat in them they don't
center and seal in the bore as well, this aggravates the fuel collecting at the bottom and soaking the lower side rings .
With a bit of RPM and load it helps keep the chambers from loading up till the heat comes in to help/

The nice smooth drive-away prevents many issues, and causes none.

Boxer engines usually like a hot turn off (Don't let them just sit and idle then turn off, light uptic in rpm to maybe 1500 then cut the ignition.) and a warm start. (Start and drive away slow)
In the ones i've played with, any boxer with a higher performance envelope has some issues with rich at idle. (I started on Bugs, subaru's moved on to a 69 911, and now the 996..)
Hard to make them pull hard at the top end and stay lean at the bottom.