My first compression test 3VZE, what do y’all think?
02-01-2019, 04:23 PM
#1
My first compression test 3VZE, what do y’all think?
Made an attempt at a compression test today on my 1988 4Runner with 3.0
3VZE spec should be between 142-171
Results:
1: 170
2:150
3:165
4:160
5:155, then 120 on next two tests
6:150
its quite possible I did something incorrectly as this was my first time doing this, but if these are correct numbers should I be concerned about #5? Should I be concerned about the variations in psi.
3VZE spec should be between 142-171
Results:
1: 170
2:150
3:165
4:160
5:155, then 120 on next two tests
6:150
its quite possible I did something incorrectly as this was my first time doing this, but if these are correct numbers should I be concerned about #5? Should I be concerned about the variations in psi.
02-01-2019, 06:17 PM
#2
Do it again, and then again.. Take average..
Make sure you have a well charged battery, better is a second vehicle or good booster box. The constant cranking creates heat in the cable, heat creates resistance which will alter the cranking speed.
Why go thru all this trouble? Because the deviation is important, that spec is between 14 and 15 psi.
Make sure you have a well charged battery, better is a second vehicle or good booster box. The constant cranking creates heat in the cable, heat creates resistance which will alter the cranking speed.
Why go thru all this trouble? Because the deviation is important, that spec is between 14 and 15 psi.
02-01-2019, 08:00 PM
#4
Do it again, and then again.. Take average..
Make sure you have a well charged battery, better is a second vehicle or good booster box. The constant cranking creates heat in the cable, heat creates resistance which will alter the cranking speed.
Why go thru all this trouble? Because the deviation is important, that spec is between 14 and 15 psi.
Make sure you have a well charged battery, better is a second vehicle or good booster box. The constant cranking creates heat in the cable, heat creates resistance which will alter the cranking speed.
Why go thru all this trouble? Because the deviation is important, that spec is between 14 and 15 psi.
02-01-2019, 08:02 PM
#5
02-02-2019, 04:45 AM
#6
If the throttle plate isn't open all the way, you will get restriction on the flow. If the throttle.plate isn't consistent you will have deviation.
Try again with the throttle opened. If you still have deviation do the "wet" test like the manual says by inserting some oil into the cylinders.
Last edited by Co_94_PU; 02-02-2019 at 04:48 AM.
02-02-2019, 04:49 AM
#7
First off these ECU do not implement the clear flood mode, and second if they did that requires the throttle pressed and held to the floor.
If the throttle plate isn't open all the way, you will get restriction on the flow. If the throttle.plate isn't consistent you will have deviation.
Try again with the throttle opened. If you still have deviation do the "wet" test like the manual says by inserting some oil into the cylinders.
If the throttle plate isn't open all the way, you will get restriction on the flow. If the throttle.plate isn't consistent you will have deviation.
Try again with the throttle opened. If you still have deviation do the "wet" test like the manual says by inserting some oil into the cylinders.
It's probably best just to hold the throttle open under the hood instead of messing with the gas pedal right?
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02-04-2019, 05:38 PM
#8
How you going to turn the key and hold the throttle open? If you have a helper have them hold the throttle and turn the key. You just have to watch the gauge. Mine has a high mark setting like most. So I hook my gauge up pull EFI fuse and spin it over with my foot on the floor. Thats how I was taught. Don't see why it would be different holding the throttle open in the engine compartment. But it seems like it would be more of a PIA overall and require 2 people. If your tester doesn't have a high mark hold in it then you may need 2 people. Also run it a minimum of 3 times to get the average.
02-05-2019, 11:04 AM
#10
How you going to turn the key and hold the throttle open? If you have a helper have them hold the throttle and turn the key. You just have to watch the gauge. Mine has a high mark setting like most. So I hook my gauge up pull EFI fuse and spin it over with my foot on the floor. Thats how I was taught. Don't see why it would be different holding the throttle open in the engine compartment. But it seems like it would be more of a PIA overall and require 2 people. If your tester doesn't have a high mark hold in it then you may need 2 people. Also run it a minimum of 3 times to get the average.
02-05-2019, 11:05 AM
#11
02-05-2019, 11:52 AM
#12
Registered User
I wedge the throttle open at the throttle body with a clothespin, or maybe a screwdriver, and use an old school pushbutton jumper between battery positive post and the solenoid terminal on the starter.
Then I can crank without any fuel issues because the ign key is not even in the switch. Just gotta make sure to find neutral, or park, if auto.
Then I can crank without any fuel issues because the ign key is not even in the switch. Just gotta make sure to find neutral, or park, if auto.
02-05-2019, 12:43 PM
#13
I wedge the throttle open at the throttle body with a clothespin, or maybe a screwdriver, and use an old school pushbutton jumper between battery positive post and the solenoid terminal on the starter.
Then I can crank without any fuel issues because the ign key is not even in the switch. Just gotta make sure to find neutral, or park, if auto.
Then I can crank without any fuel issues because the ign key is not even in the switch. Just gotta make sure to find neutral, or park, if auto.
02-10-2019, 10:16 AM
#16
Registered User
Refer to the explanations on the pdf that old87 posted. It explains the increase, though no particular number or range given.
I would surmise worn rings, hopefully.
Before I can re-read, how's the engine running through the rpms?
I would surmise worn rings, hopefully.
Before I can re-read, how's the engine running through the rpms?
02-10-2019, 10:20 AM
#17
The engine typically runs well at all RPMs. Nice steady acceleration. Tho there is some occasional jerking when letting off the throttle.
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