Compression test-Fuel pump relay

[tom26]

Hi on a compression test if u dont remove the fuel pump relay will you get a incorrect reading?

[Royston]

No, but you might fuel up/flood the engine

[tom26]

So the test reading will still be valid?

[mowgli]

well, if there is fuel being dumped into the bore, you will get a certain amount of 'wet' sealing

you are meant to do a dry test, then follow it with a wet test, by squirting some engine oil into the bore from an oil can.