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My '78 has K-jetronic. Before putting the engine back together again after head reconditioning, I thought it a good idea to have the injectors checked and recondition as well, like is often performed on diesel cars. So far, I received one reply on a request for recondiotioning, stating it is not possible to have them reconditioned. Cleaning is the only option. What is the cause of this? Shortage of parts? Or is it not possible to recondition the injectors due to the construction?

docmirror

About all you can do is soak them in a bath of injector cleaner, B12 chemtool, or Seafoam. After that, blow them out as well as you can. Nothing to do on a CIS unless you have the big test jig to measure flow rate. There aren't many of the big test jigs around any more.

I've used an Ultrasonic bath with some alcohol, and then Seafoam.

<edit: I recalled seeing something for testing on Pelican. This guy seems to have the right plan. http://forums.pelicanparts.com/porsc...injectors.html post #14 >

jpitman2

With the right gear they can be backflushed - force the pintle (little piece in the end)open with pressure, trap it with a little tool , then blow solvent back through the end. There is a fine gauze filter inside, and this is the only way to blow stuff back out. Testing should give an even sparay cone.
My local wrench can do it (in Oz), so look for a Bosch injector testing service....
jp 83 Euro S AT 54k

linderpat

replacements are $69 on 928 Intl site. Not too bad compared to the later styles for L jet etc

jpitman2

The brass MB versions (shorter than 928 units) are CHEAP - ~$25 area. Do a search here for the part no, and where to look for them. Some have installed them with no downside.
jp 83 Euro S AT 54k

GlenL

What I was going to say. Plus...

https://rennlist.com/forums/928-foru...injectors.html

hoffmma

I had a local diesel specialties shop clean and flow mine. 3 were bad and I replaced them with the MB injectors without any issue. The local advanced auto parts had the injectors. I had them look them up for a MB 280 I think.

SeanR

This is the rig my dad used in his shop for 30 some years, got it from him a few years back and it does a wonderful job of cleaning out CIS injectors.

linderpat

Boy, it would be nice to try that tool! I just ordered a new set of the MB's from Roger, and once I pull my old ones, I will want to clean them and keep them as spares. If I send them to you Sean, would you clean them for me? I'd be willing to pay a reasonable fee.

SeanR

No problem at all, just send them to Rog and I'll take care of it.

linderpat

Thanks Sean, will do.

linderpat

Sean - are you going to Frenzy this fall? If so, can I bring the injectors for you to take back to TX for cleaning? I have since put in the MB shorties from Roger, and they work great. I just want to have the spare (and original) set ready to go for possible future use. I can mail them if you prefer.

Mike LaBranche

I just 'cleaned' a set with carb cleaner and 80 psi of compressed air. Fill the injector with cleaner, push compressed air through with a rubber nozzle tip, repeat until you get a nice cone. Took 4 or 5 iterations per injector. Worked like a charm.