just did a compression test

[jcivic]

well i just did a compression test and all 4 cylinders are holding at 9bar what should it be?? the car is a 94 ep82

 

[iamlegend]

9bar???

ermm 160-190 across all four.

 

[Gilly2006]

just worked that out and thats 132 psi across all 4 cylinders which is a little low. anything between 180-150 is ok.
hows the car running?

 

[Sheldon]

tis a bit low but if its 9bar on all cylinders then thats perfect..

 

[Somhairle]

Was the compression test done with the throttle wide open?

 

[Sheldon]

Was the compression test done with the throttle wide open?

good q.. and engine warm?

 

[jcivic]

no engine wasnt warm and no wasnt fully open throttle.... egine is abit smokey but duno if that turbo seals or not hence y i did the compression test

 

[Somhairle]

no engine wasnt warm and no wasnt fully open throttle.... egine is abit smokey but duno if that turbo seals or not hence y i did the compression test

You will not have got the proper reading then mate.

Warm up the engine, and hold the throttle wide open while cranking.

 

[jcivic]

You will not have got the proper reading then mate.

Warm up the engine, and hold the throttle wide open while cranking.

what difference should this make?

 

[billybob]

what difference should this make?

it will make you get the correct reading ..

 

[jcivic]

it will make you get the correct reading ..

i understand the warm engine but why open throttle?

 

[billybob]

i understand the warm engine but why open throttle?

it just has to be done that way lad..do it and youll come back with a better result id say your turbo seals are screwed

 

[GT-TD04]

Just did my own on a slightly warm engine, 165psi all round

Jcivic,when you come down to me at the weekend ill do it for you if you want

 

[Texx]

i understand the warm engine but why open throttle?

The throttle does just that, it throttles or restricts the amount of air that enters the engine. If you carry out a compression test with the throttle closed your are limiting the amount of air the engine will be compressing during the test, so it will result in a lower compression pressure reading. With the throttle wide open, more air will enter the engine during the compression test and so the results will be more accurate.

 

[jcivic]

Just did my own on a slightly warm engine, 165psi all round

Jcivic,when you come down to me at the weekend ill do it for you if you want

i wont be driving the car man i need to do a good bit off work on it cheers for the offer