Compression testing with no ECU?

[Redtop_240]

Is this possible or will the compression be off......

We tested my buddies newly swapped SR and from the front of the car we tested the closest to me to the furthest from me....(im standing directly in front of the car)

closest to the radiator.......

50 Psi.

next

65 Psi.

Next

125 Psi.

Next

75 Psi....

Im no genious but i would think that no matter the ECU the compression is judt the air its breathing and compressing correct?

I dunno .....

anyway we did this with no ECU on the car...(they sent him a WC instead of a 62, we kinda wished they had sent him a S14 VTC along with the corresponding ECU)

Anyway any imput would be appreciated.....

-Jeff

[ryan hagen]

are you turning it over with the starter? i found that by hand it doesnt work.

[JagdStealth]

Yeah, you need to be turnnig it over with a starter, cranking by hand won't build up enough compression.

The compression numbers will be the same regardless of ECU. If you're getting those numbers with the engine in the car and cranking over off of the starter, then you have a bad motor :(

[96twofourty]

turn it over with the starter and open the throttle body

[steve shadows]

:newbie:


the ecu has nothing to do with the engine the ecu is peice of electronics the enegine itself is a mechanical pump... the starter runs on its own seperate power harness to the battery and the ground thru a relay in the fuse box. Make sure your throttle body is open when you do the compression test.... :duh: