Compression Test...

[RPS13 Rocket]

Going to look at a car tomorrow, wanted to know about tips that can be shared on doing the compression test. And what the prefered method would be.

[corn322]

this is how I did it1-->

do it while the engine is warm1.release fuel pressure (keep fuel pump fuse out)2.unplug all spark plugs3.screw in tester into plug #1 hole4.floor throttle, turn key and let engine turn over untill needle on the tester stops going any higher. don't run for more than 30 seconds.5.release pressure from tester6.repeat 4 and 5 for the other plug holes

[Touchdown038]

Do what corn said, except only let the needle bump up 5 or 6 times. And make sure you ground the coil wire with one of your plugs so you don't accidentally ignite the fumes coming out of the empty spark plug holes.

[humpy012]

or if the sparkplugs are out they wont be sparking, if they are disconnected

[corn322]

yeah, I forget to mention I unplugged the ground wire for the coil. I left it in and had my friend hold the tester so I could see it. he got a nasty shock. it was pretty funny.

[YomnyM]

what compression should it read on the cylinders, whats good, bad and average. Thanks

[toki]

Just be careful not to misthread, if it seems like it didn't take long enough to stopped early, take it out, do it again. That happend just a few days ago on my friends car when we were doing it and we had to cut the hose and use a ratchet to get it out. $25 down the drain. Oh well. Just be careful and be safe.

[C-Kwik]

this is how I did it1-->

do it while the engine is warm1.release fuel pressure (keep fuel pump fuse out)2.unplug all spark plugs3.screw in tester into plug #1 hole4.floor throttle, turn key and let engine turn over untill needle on the tester stops going any higher. don't run for more than 30 seconds.5.release pressure from tester6.repeat 4 and 5 for the other plug holes

I would just disconnect the fuel injector harness from each injector rather than relieving fuel pressure. I'm assuming this is a 240sx of course since they are easy to get to. It will also ensure no fuel reaches the cylinders.

[Touchdown038]

How do you go about doing that? Do they just pull straight out?

[quiksilvia]

what compression should it read on the cylinders, whats good, bad and average. Thanks

search

[YomnyM]

bro i did search and thats how i got to this thread, damn, is it so hard to type down 9 numbers, thanks anyways, hope you could find the same help in the future.

[Touchdown038]

Last time I checked it's 12 numbers - 3 for each of the 4 cylinders. 3 x 4 = 12

[quiksilvia]

im not ur bra...

[quiksilvia]

and he did a geo metro swap, so he only has 3 cylinders

[YomnyM]

well if you read before you talked i ask for what would be a good compression an average and a poor, ex. 185, 175, 155. thats nine numbers, isn't it? lol nice, about the metro swap, i could tell you have no life, you're the only one responding.

[quiksilvia]

i have a life, someone has to make fun of the poor defenseless noo-b's on nico....and i have taken that role.

[4felix20]

Quote »192psi (standard)142psi (minimum)14psi difference limit between cylinders

-demetrius[/quote]

[NISTECH]

here ya go quicksilvia got the info for ya

How to remove a Metro engine.step 1 place your left foot in the right front corner of the engine compartment on the inner fender well.step 2 place your right foot on the front bumper near the license plate.step 3 Grab the intake manifold with your left hand near the front.step 4 Grab the exhaust manifold with your right hand near the rear of the engine.step 5 Slide the engine to the right of the car off the trans input shaft and lift. step 6 Place engine on upper radiator support and climb off of car and take engine to engine stand.

took me like 30 mins to get my 3 cyl engine out of my metro.

LOL HA HA.........HA

[4felix20]

i drove a 3 cylinder metro cross-country...twice. seriously :puke