passed this tip along to me - but I’ve never tried it.
Does anyone have any experience with an RPM
“Drop Testing” a Diesel Engine:
Start the engine
& warm it up. With the warmed-up engine idling at between 800 & 1000 rpm
1. Loosen the first fuel
line connector to an injector (carefully - there’s VERY high pressure here), disrupting fuel
flow to that cylinder. Record
the level to which the RPM falls for cylinder number 1.
2. Repeat this in turn for each cylinder, one at a time.
3. When all cylinders have been tested, look at the numbers recorded. They should all have a similar (very close to the same) RPM drop.
4. If one cylinder has significantly less RPM drop than the rest, it may have fuel injection, or compression