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.

 

Were you also WOT when performing test?

 

 

 

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. Finally, the efi fuse should be removed to keep the injectors from firing.

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.

 

Thanks, so if the throttle plate isn't open all the way, would it lower compression readings?

It's probably best just to hold the throttle open under the hood instead of messing with the gas pedal right?

 

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.

 

It is easiest to simply hold down the accelerator pedal all the way to the floor while cranking.

Here is the Toyota Factory procedure for a compression test:

 

Thankfully my wife is nice enough to be my helper. Yea I didn't think there was really any difference in flooring the pedal or holding the throttle cable. Will do another test (consistent this time) this evening hopefully.

 

Thanks gonna give it another shot! I will remove EFI fuse this time. Hoping for consistent results.

 

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.

 

Good idea. there are so many times when I have no helper.

 

 

 

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?

 

 

Good comp check.