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Helmsy Helmsy is offline
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Join Date: May 2008
Location: South Australia
Posts: 281
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Hmm a tricky situation to say the least. Unfortunately trial and error is usually the way to find the culprit(s).

Check your flow rates from the pumps (per the manual) and injectors. If they are correct and you have tried different WURs (correct pressures) with the same bad results that points to the fuel head. Unfortunately due to years of differing conditions these things are prone to variations in problems and solutions.

I bet not all fuel heads have 3 shims. Mine had none and I had to add and remove many before finding a nice balance. Too high system pressure resulted in 'run-on' (dieseling) in my case. The manual is a 'guide' for settings and pressures and slight adjustments can have large differences.

Unfortunately you would be better to get an adjustable WUR. Adjust your pressures and find exactly where your car is happy. You may be able to raise system pressure and lower control pressure or vice-versa and find it runs fine. Otherwise a fuel head rebuild is on the cards.

I have found by accident mine is running about exactly the same cruise and idle afrs (I don't know if this is normal - I thought a richer idle would be better). I still have an enrichment problem under boost even tho I have an RPM solenoid active but anyhoo thats a whole nother episode.

Good luck and post your findings!
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'85 930 - Black on Black
'95 993 Turbo - Silver

Last edited by Helmsy; 09-16-2011 at 06:07 AM..
Old 09-16-2011, 06:04 AM
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