how long for injectors to break in?

[broncobuyer]

i replaced #8 injector and o-rings on other injectors and drove 10 miles but cylinder 8 still fails contribution test, how long does it take for injector to break in? also on my taskmaster scanner i have info for cylinder rotational vel %, what is this reading for? my cylinder 8 is at 6.3% but all others are at 0%.

[AFBLUE]

takes about 50miles to work all the air out of the oil system. not sure on the Rel %?

[harrys91rs]

Originally Posted by broncobuyer

i replaced #8 injector and o-rings on other injectors and drove 10 miles but cylinder 8 still fails contribution test, how long does it take for injector to break in? also on my taskmaster scanner i have info for cylinder rotational vel %, what is this reading for? my cylinder 8 is at 6.3% but all others are at 0%.

Cylinder rotational vel % (aka PERDELs) should be 0's, ideally. Its the % of crankshaft rotational loss after that specific injector fires. I think anything over 3% will fail a contribution test, correct me if i'm wrong.

[broncobuyer]

its been 50 miles now and my cylinder 8 still is at 6.3% on rotational vel. when i replaced the cylinder 8 injector i did a compression test and that was good, so if its not the injector or lack of compression then why does 8 still fail counterbalance test? at idle it reads 6.3 % but if i raise rpms past 800 it reads 0%, so the injector must be good if it only acts up at idle, could it be my injector module or maybe a weak pump?

[S.S construction]

when we install injectors will say 100 to 150 miles to ensure correct break in on thme to work all air out.

[broncobuyer]

i will give that a try then, might take me a week or two to rack up them miles.

[CSIPSD]

The rotational test only works at idle, once you come off idle it quits working.

Give it some time.