Compression issues

[makeitfit]

My truck has SUDDENLY become a pain to restart once it's been running :nenau
It runs like a dream and is fast :sly however the MPG has gone down suddenly too.
Could this point to a compression failure or some other fault. I've no warning lights on, no water usage, not running hot either, No smoke except after it eventually starts:doh
What's the best way to test comp on the 2.7 and what sort of figures should I be seeing?:thumbs

 

[solarman216]

As with any other diesel, remove all glow plugs, and with an adapter fit a pressure gauge with a one way valve into the glow plug hole number one cylinder, and crank it on the starter as long as the starter spins at a good rate you should be looking at around 400 psi, but it is in the manual, then test the rest, Rick

 

[makeitfit]

Cheers boss, I'll try n get at it later in the week.
In your experiance, would you be thinking piston rings or head gear issues?:augie

 

[solarman216]

If you are not pressurising your water system then rings/valves but get the numbers first, all 4 pots should be the same, if one is down by 20 psi or more valve on that pot probably, but to prove it inject a small amount of oil (5 mililtr) into that pot and try again, if it improves = rings if not valves, Rick

 

[makeitfit]

Cool, cheers :thumbs