Carried out a vacuum test last night and appear to be getting low readings at idle (about 30kPa - I know it's a crap parameter but the guage is indicating in the POOR region at idle). No other fluctuations or indications of problems with say opening throttle quickly etc.

With compression test seemingly OK there must be another explanation. Perhaps slightly open or worn throttle butterfly valves causing this hence maybe why the compression test readings with closed throttle were not what you expected. I will post more on the message board in the near future.

Ian

Ian:

Good to know. I guess that throws my theory out and is bad news for Phil and Matt. I'll wait till someone else runs a concordance test, but I'm surprised it did not drop further with a closed throttle. 5 psi is nothing.

Neil Deshpande
http://www.neilwerke.com

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Did the closed throttle test by default - I forgot to open it on the first cylinder test!
Reading was 180 PSI after 4 cranks. Didn't do any other cylinders. Throttle open on the same cylinder produced 185 PSI