jwaggz82

iTrader: (1)

I bought a compression test kit to test my engine. Which fuse do you take out before running the test?

What is the safe range that it should read if the engine is up to par?

scuds03

Whats the mileage and symptoms your car is showing?

jwaggz82

iTrader: (1)

miles on my engine is around 35k and miles on my car is 60k - no symptoms, i just want to run a compression test to see how my engine stands. Cost me $25 for the kit so its worth it.

tcscion06

disabled the ignition and the fuel pump. so take out the ignition fuse and the fuel pump fuse or unplug the injectors and the coil packs

jwaggz82

iTrader: (1)

ohhh ok - it was the ignition fuse. i have to look up which that is.

tcscion06

I forgot the exact specs for the compression test.It should be around 180ish psi I think. If all the cylinders compression results are closely the same then the piston rings should be still good

jwaggz82

iTrader: (1)

^ my friend said 189 and anywhere from 177 to 189 is good. Can anybody second the exact specs?

tcscion06

it doesent really have to be exact...as long as they or close enough....if one is 180 and the other is 150 then the one with the 150 would have bad rings

jwaggz82

iTrader: (1)

^ahhhh right. good deal. thanks for the feedback. So you would assume that at the most they should be within 10 of each other. to say the rings are good right? or should the difference be less? I know there will be a few lb error rate in my tester because its not a really good one (but thats fine).

scuds03

Dont forget to make sure the throttle plate is in wide open position when you do the test. Also if you realy want to test your motor you need to to a leak down test as well.

jwaggz82

iTrader: (1)

i dont really think there is a reason for such if the compression test is fine. if the compression test isnt good then yea - i would have to do a leakdown to find out exactly what is bad.

cmcpride

iTrader: (3)

remove EFI fuse , it controls fuel.
max 189 min 145 psi , differance from each cylinder no grater than 14psi

jwaggz82

iTrader: (1)

^good deal - that sounds like it was from toyota.

EFI fuse, i havent looked inside my fuse box in years ... are they labeled?

cmcpride

iTrader: (3)

yes, or you could also remove efi relay, 15A IG2 fuse , c/opn relay. your choice

jwaggz82

iTrader: (1)

checking the compression was easier then i could have thought. Anybody with any questions ask away. Here is a link to look at taking the plugs out if ya have any issue.

https://www.scionlife.com/forums/viewtopic.php?t=43053

once one plug is out you take out your 2 fuses as said above and then connect the gauge. Floor the gas and turn the car over maybe 5 times till the pressure stops going up.
I had 177,180,180,180 so things are pretty much perfect.