MFI Bosch Injectors (69-73)

[bavaria911]

Gent's,

I have found a new (maybe NOS) set of six Bosch MFI injectors.
I want to confirm if they are all the same and fit my 1972/73 MFI system?

2 x injectors have EP/DCC45 R3 BOSCH Germany and stamped just above these numbers are "501".
4 x injectors have EP/DCC45 R3 BOSCH Germany and stamped just above is "411".

Can an MFI guru confirm for me these are all the same please?


Vr,
Bavaria

[Grady Clay]

Scott,

I wouldn’t worry about that code, it is a manufacture date. Are the nozzles in Bosch packages or Porsche re-labled?

The most important issue is if they are good. They must open in the specified pressure range, have a good spray pattern and completely seal when below the opening pressure. The original set of six were matched to each other and the pump by the factory before they were installed in a new engine. They hand serial numbered (1-6) each injector. This was done for California and 49-state cars, I am not sure about RoW. I know the best MFI pumps were reserved for California and the next best for 49-state versions.

We found new parts that were out of spec – probably 1/10 in the early–mid ‘70s. Your first order is to have them tested. It may take some soaking in an appropriate cleaning solution and using an ultra-sonic cleaner. You may even have to install then in a good running MFI engine and put some miles (km) on them. With a sample of six, I wouldn’t expect all to be good. With a sample of 18, I would expect 6 really good, 6 OK and 6 I would return unused. The quality control on newly manufactured parts may be better now but I suspect you will only find used or NOS in variable condition.

Even fairly bad nozzles work OK at full throttle and high power. The critical area affected by the nozzle condition is at idle, just off idle and light throttle cruising. These are also the situations where throttle body condition, correlation and pump calibration also have the greatest effect on proper running. These are also the conditions where poor running is most aggravating. Good nozzles emit an audible chirp at idle that you can hear above all the engine noise.

Regular testing of the nozzles is part of CMA. If you end up with several sets of nozzles, use your worst (but still functioning) set for a DE or some “spirited driving” and they may recover.

The two throttle links and the (’69-’72) left tin should be easy to find. The ’73 left tin will be more difficult. Have you looked for a NOS heat exchanger? Sounds like you are making good progress.

Best,
Grady

[bavaria911]

Grady,
Thanks. I'll go to the man at the local Bosch dealer/ shop who rebuilt my 2.4 S MFI pump and have him proof the injectors.
All six came in Bosch individual boxes that a son was selling from a older man (Father) that died. He says the garage was full of parts and stated selling on Ebay a few weeks ago. I asked for other early porsche parts, but all were sold. I paid $35 for each injector - I guess it was a gamble.
Thanks again for the sound advice.
Bavaria /Scott

[bavaria911]

Anyone have a chart to see if these are the correct injectors?

Bump!!