Reviving stuck injectors and Integrale 16v injectors in an 8v

[Alex RP]

Originally answer to member samo in viewtopic.php?f=13&t=2624, moved here on GC's suggestion:
I believe you have IW025/01 "yellow" injectors. Those are low impedance, and as such, tend to respond well to standard unsticking techniques. Even as new (now NOS), they are nowadays often delivered in stuck condition. To make them work, we use this procedure:

1) Remove rubber O-rings.
2) Put them in DOT 4 brake oil bath (feel free to improvise here) at about 60 °C for one minute, while pulsing them at 12V 50 Hz (AC transformer and a diode will do), with 3-5 Ohm resistor in series to limit the current. If they start to "click", proceed to the last step, otherwise go to step 3.
3) Remove them from the oil bath, keep the pulsing as above, put a hose over spraying side of injector (it should be tight against injector body), and apply compressed air (4-5 bar usually persuades even the most stubborn ones). If they start to "click", proceed to the last step, otherwise go to step 4.
4) Keeping the pulsing as above, try tapping them in middle with a mid-sized spanner, as mentioned by other members. We hang them by a hose left from step 4), but this is not really essential. If they start to "click", proceed to the last step, otherwise they should be binned.
5) Disconnect pulsing, wash them using brake cleaner, connect pulsing again, spray brake cleaner through them. Put the O-rings back. Fill the injectors with clean diesel from fuel rail side (while pulsing), held vertically (fuel rail side up, spray side down) and stop pulsing. Cap both sides and store in vertical position (as while filling). Their shelf life will be very long this way.

If you are considering using integrale 16v injectors, beware that, apart they flow more, they are also high impedance type, which means battery voltage compensation map should be updated. That said, we use them successfully as 8v upgrade, coupled with 2.5 or 3 bar MAP, distributorless ignition and our programmable ECU.

Hope this helps,
Alex

[samo]

Hi,

As you guessed correctly I have the yellow top injectors. I tried pulsating them manually and soaking them in gasoline and diesel. But I had no success!

I will try your method and report back when I get the chance.

But I have managed to obtain NEW 8V original injectors for a more than reasonable price of 40€/pcs! So the problem is solved but I will try to revive the rest as it's a shame to throw them away as they are geting rare! Thank you very very much for the indepth solution and also I would like to thank you for pointing out the difference between the 8v and 16V injectors as I didn't know about that!