Hi Paul,
The plugs are NGK PZFR6H. I have attached an image of them all sooted up here:
https://1drv.ms/u/s!AmWxme0O8FrMoGrVi4rwuf6ql6zK
2 avenues of investigation at the moment, battery sourcing and air pressure.
For the battery, as I said, it is hard to find something suitable and stay within my 330mm length requirement. Over here in europe we have CCA EN which is lower than SAE but the conversion is not really defined (I think 800 EN should equate to about 850 SAE). I found that if I go for a car battery (rather than a marine/leisure battery) I can get some higher CCA numbers. The boat has a small fish finder, a manual bilge pump and a switch to light up the gauges that I never use (I don't have nav lights so do not boat at night) so the demands beyond starting are tiny, if not irrelevant I guess. Seems that many people just use car batteries for their boats without too much issue and pay more attention to keeping them topped up over winter. Do you have any comment on this?
For the air pressure, it would be useful to know all the areas to check:
- pipe from compressor to bottom of air rail
- air regulator - is there a way to check that this is working properly?
- how can I verify that the air compressor is producing enough pressure?
- any other likely sources of air leaks?
I had an issue before with the hose between air rail and fuel regulator splitting and then engine would not run. Found the split, cut out that section of hose, put it back on but then found the wire hose clips were not adequate and were allowing air to escape at the hose connections. I have since replaced them with better clips and can no longer feel any air escaping. I have ordered a new hose. All the checks and readings have been taken after I fixed this hose issue. Does this hose along with the fuel regulator only affect the fuel pressure?
Also, I mentioned I tried to measure the resistance across the pins of the water temp sensor and could only get 2000ohms. My service manual says it should be 2.45ohms at 20 degrees C. I tried multiple times and with 2 different volt metres and could not get a good reading. Is this sensor likely to be suspect or am I measuring the wrong thing? Of course, if the sensor is faulty, its not telling the ECU that the engine is warming up. Also couldn't get a good reading from the TPS but could from the fuel injector.
Thanks a lot.