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[Wagdog]

I had troubles with leaking injectors and a blocked WUR mesh filter. The leaking injectors filled the sump with petrol and the pressure line back to the WUR was blocked. Too much cranking and no start! I purchased a small ultrasonic jewelry cleaner on Ebay and after soaking the injectors in carburettor cleaner , put them individually through the bath in water with a little dishwasher detergent. Water with and without detergent was alternated through treatment. Fine debris was deposited in the bath. Each injector had a total treatment time of 30 minutes and was inspected with a 10X hand lens at intervals. All looked pretty good at the end of the process and gave a satisfactory ( but not quite perfect) spray patterns in a plastic bottle test. They no longer leaked in a no start situation.
After this I tackled the WUR in the same way, taking off the chamber containing the bimetallic strip and the control plunger. The vacuum chamber was not removed. The mesh filters in the inlet were soaked in situ for a couple of days in carburettor cleaner and then that section of the WUR was immersed in the ultrasonic bath for a total of about 2 hours in 8 minute bursts. Blowing through the mesh with an 8.5 mm diameter plastic tube ( from a pump body wash bottle) was done for a flow check. When it seemed clear, a final check was done with a funnel, petrol and gravity feed. A flow rate of 50 mL in about 17 sec was achieved and accepted. The WUR was carefully reassembled with a new Viton O-ring 14x1.5 on the diaphram and a new Viton O-ring 19x3 sealing the electrical connection. A spot of grease was used to align the control plunger operating rod. I have not done a final check on the operating pressures, but the car now starts easily, hot or cold, and runs well. I have injector cleaner( Risolone)in the tank and this seems to have dealt with some initial misfiring.
There is a lot of information about WURs (Warm Up Regulators, Control Pressure Regulators) on the web.

[Carrera RSR]

Have you jar tested the injectors for equal flow and spray pattern? Usually cleaning of our injectors improves their issues but doesn’t always give 100% results. The control pressures will need checking and probably adjusting after pulling apart the WUR
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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[Wagdog]

My plastic bottle test was the same as a jar test. Control pressures will be checked after the broken manifold stud is replaced