how to do a compression test

[acrbill]

Anyone have words of wisdom on how to perform a compression test on these cars?

I have a tester and have tested other cars but there are a few bits that are different.

1) easiest way to stop fuel- I assume a fuse pull but am wondering
2) easiest way to stop spark
3) how to crank engine- sounds foolish but we have the one touch starter
4) on my other cars I would keep the TB wide open which is easy with a cable but no so much with DBW.
5) do you pull all the plugs or just one at a time?

let me know

 

[alex12gt]

To stop fuel we pulled the fdm or what ever harness in the trunk
As far as starting just flip it on and let it spin 3 times and shut it off
To stop spark disconnect all the coils
And we just did one at a time
Didn't mess with the tb

 

[Blazer707@TBR]

Pull all the plugs. More accurate test. Crank 5 rotations. Your psi will depend on altitude but shouls be no more then 15% difference.

-Thomas

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

 

[turbosha]

Back in school we were taught to open throttle all the way and crank till the needle stopped moving. It doesnt matter if you pull all the plugs or not. Engine will crank easier. As long as you use the same procedure for all cylinders.

 

[acrbill]

To stop fuel we pulled the fdm or what ever harness in the trunk
As far as starting just flip it on and let it spin 3 times and shut it off
To stop spark disconnect all the coils
And we just did one at a time
Didn't mess with the tb

Thanks bro. Some things I will add.

Disconnect the fuel harness in the trunk and then start the car to let the pressure release. I didn't do this and all my plus were wet with gas so it was harder to get a read on them.

When doing the rear most passenger side be sure to be mindful of the positive battery terminal, if you hit it there is a good change you will blow the power steering fuse. I heard about this and can see why it would happen.

For those wondering all my cylinders were between 170-176 with #8 being the strongest. I worked on the drivers side starting at the front and moving back. The first two read 167 and after the rest of the cylinders read in the 170s I retested and got 172 in both.

I have primarily been running the AED auto lopey idle tune for those who may be concerned about the tunes affects on the motor.

 

[Ultrakla$$ic]

I have primarily been running the AED auto lopey idle tune for those who may be concerned about the tunes affects on the motor.

So are you saying this is good or bad in your opinion? Trying to follow here.

 

[acrbill]

So are you saying this is good or bad in your opinion? Trying to follow here.

I have been running the AED tune for awhile and my motor is strong and consistent. :thumbsup:

 

[Ultrakla$$ic]

I have been running the AED tune for awhile and my motor is strong and consistent. :thumbsup:

That's what I thought you were alluding to but wasn't sure. Glad all is well with your whip!:rockon: