I thought I’d post something that I ran into during my recent cylinder head rebuild … dirty fuel injectors.
Since I still had the original Bosch injectors that were installed in 1989 I decided to either replace them (expensive, around $380) or send them off to be refurbished (less expensive around $160).
Then I thought why not do it myself ? So after researching the internet I decided it was very doable. The main culprits I found are the fuel filters that get clogged up and rusted, and hardened, leaky O rings.
A rebuild kit for 6 injectors cost me $17. This included new filters, O rings, and pintel caps …
I used a car wheel valve stem and removed the schrader valve. The large end of the rubber valve stem fits nice and tightly over the intake end of the injector. The other end of the stem has the plastic screw on cap. I drilled a very small hole in the end of the cap just large enough for the plastic straw that come with a can of carburetor cleaner. I pushed just the very end of the straw through the hole and super glued it in place being careful not to get glue in the end of the straw. I then energized the injector using a 9v battery to allow the cleaner to pass through it …
First sprayed injectors as is. Ragged and dripping fuel patterns on several and none had the fine atomized mist that I was looking for.
Tested again with filters removed. Even atomized misty spray, like new.
Tested again after new filters installed. Same even atomized spray. Mission accomplished !
Removed and replaced O rings.
Did not replace pintel caps, they were just too difficult to remove. I did get one off by literally tearing it apart and since there was no difference in the spray pattern between that one and the same ones with the original caps I left well enough alone