Notices
Scion xA/xB 1st-Gen Drivetrain & Power Engine and transmission discussions...

compression test how to? doing this right now..

Thread Tools
 
Search this Thread
 
Old Sep 6, 2008 | 05:07 AM
  #1  
silverevo05's Avatar
Thread Starter
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (1)
 
Joined: Jul 2006
Posts: 403
From: Orange, CA
Default compression test how to? doing this right now..

I bought the compression test device from kragen auto, though I wanted to know if anyone knows the proper way to do a compression check on an xb

thanks in advance

oh and what are teh specs I am looking for?
Old Sep 6, 2008 | 01:08 PM
  #2  
cobb's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 2,084
From: Richmond, VA
Default

In general you disable the fuel pump and or ignition, set the parking brake, chulk the wheels and jam the throttle open. You unscrew the spark plug, screw in the tester and crank it 4 cranks or the needle bobs 4 times.

Thats what basically your cylinder psi is. Second test to see if there is ring damage is to squirt some oil in the cylinder and retest it. If it goes up, the engine has ring wear and needs to be rebuilt, if its the same and low, the valves need adjusting.

I think around 150psi is fine. Anything below 80psi, it needs to be rebuilt. If its low for one or two joint cylinder, you got a blown headgasket.
Old Sep 6, 2008 | 01:17 PM
  #3  
Ace83's Avatar
Senior Member
10 Year Member
5 Year Member
Ronin Scion
SL Member
Premium Member
iTrader: (6)
 
Joined: Aug 2006
Posts: 11,117
From: TX
Default

here a DIY, http://www.youtube.com/watch?v=ujVhVt_rhOk enjoy
Old Sep 7, 2008 | 03:11 AM
  #4  
silverevo05's Avatar
Thread Starter
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (1)
 
Joined: Jul 2006
Posts: 403
From: Orange, CA
Default

man I have dial up

it'll take me about 2 hours to see that vid

are ther any how to's anywhere

thanks
Old Sep 8, 2008 | 12:57 AM
  #5  
cobb's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 2,084
From: Richmond, VA
Default

Its not rocket surgery, the guage should of come with a manual.

Originally Posted by silverevo05
man I have dial up

it'll take me about 2 hours to see that vid

are ther any how to's anywhere

thanks
Old Nov 5, 2008 | 08:33 PM
  #6  
silverevo05's Avatar
Thread Starter
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (1)
 
Joined: Jul 2006
Posts: 403
From: Orange, CA
Default

Do I disable the ignition or fuel pump

what fuse - theres one #8 the starter system and there are many mulyiport fuel injection #5 7 18 and 30

I know its not rocket science but I dont want to mess it up

I tried search

I'm doing this now so the quicker the better thanks
Old Nov 5, 2008 | 08:39 PM
  #7  
CarbonXe's Avatar
Senior Member
10 Year Member
5 Year Member
teamNJCT
Fresh Crew
SL Member
iTrader: (1)
 
Joined: Mar 2007
Posts: 16,638
From: Parsippany, NJ
Default

Remove the EFI fuse and the EFI relay.
Old Nov 5, 2008 | 10:42 PM
  #8  
silverevo05's Avatar
Thread Starter
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (1)
 
Joined: Jul 2006
Posts: 403
From: Orange, CA
Default

it also says to disable the ignition system

and I only find the efi #5 fuse where is the relay

on the owners manual it says that # 5 7 18 and 30 are also multiport fuel injection system

so do I unplug all of them? doesnt sound right
Old Nov 5, 2008 | 10:54 PM
  #9  
Reactor's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Jul 2006
Posts: 682
From: Southern California
Default

Standard compression: 213psi
Minimum compression: 156psi
Max difference between cylinders: 14psi

Disconnecting coils is another way to disable ignition.
Take all the plugs out, screw in the tester, floor the trottle and crank the engine. Watch the gauge, usually 5-7 revolutions is enough to obtain the max reading.
Old Nov 5, 2008 | 11:07 PM
  #10  
silverevo05's Avatar
Thread Starter
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (1)
 
Joined: Jul 2006
Posts: 403
From: Orange, CA
Default

no need to stop fuel injection?

sorry I'm such a noob

how do you disconnect the coils?
Old Nov 5, 2008 | 11:18 PM
  #11  
Reactor's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Jul 2006
Posts: 682
From: Southern California
Default

Each of 4 coils have an electical plug on them with wires, just unclip them.
Better to disable fuel like thay said, just to be safe.
Old Nov 6, 2008 | 03:56 AM
  #12  
cobb's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 2,084
From: Richmond, VA
Default

I no longer own an xa, however if its silver and from a dealer in richmond, I already messed up the engine.

Anyhoo, its in a box under the hood near the battery, inside the cover it says what the fuses are for, one should say efi. Unplug that, Dont bother with the coils other than plugging your plug back into the one for the cylinder you are testing and touch that to the engine block, valve cover, etc.

Either way, you need to cut off the ignition or fuel, not necessarly both. This way when you crank it wont start and lets you do the test properly.

Ok, cant find the fuse? Unplug all spark plugs and do it that way. May want to head to an advance auto or auto zone in your area for some help, its easy to do a compression test and in their parking lot.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
alexdrummerr30
Scion xB 2nd-Gen ICE & Interior
7
Sep 8, 2018 12:18 PM
mudguy
Scion xB 2nd-Gen Drivetrain & Power
7
Oct 22, 2015 04:31 PM
ScionLife Editor
Scion News Forum
0
Sep 16, 2015 10:00 PM
JonathonK
Scion FR-S Owner's Lounge
0
Sep 16, 2015 12:27 AM
mcnick0495
Scion tC 2G ICE & Interior
0
Sep 8, 2015 02:58 PM




All times are GMT. The time now is 04:01 PM.