Compression Test

[Mick]

Does anyone know exactly how 2 do a compression test on a rb25det and what the factory figures are ?

I kinda know how but a few tings im not sure about.

Like is it ok to leave the cross over pipe (IC to Throtle) and the hose that goes from one cam cover to the other off while cranking te engine ?

Am i suposed to have accel pedel flat to floor while cranking ?

When is the best time to do it (engine warm or engine hot) ?

So from my knowledge so far,

1) Remove fuel pump fuse or block fuel hose after filter.

2) Remove everything in my way to get to the plugs.

3) Unplug coil packs, remove 1 plug and stick tester in.

4) Hold open throttle fully and crank engine until the reading steadys.

5) Put plug back in and repeat for each cylinder.

[ex-static]

you should be able to tell slightly if your plugs are screwed anyway mate.

I rekon just get a set of 0.8mm gapped copper plugs and chuck em in, shouldnt cost you more than $25 bucks.. just remeber to change them every 10,000ks

[Mick]

The plugs are only a month old, carnt remember what brand, but they cost me $28each. I wana check there gap, so i wanted to a comp test as well..

The main thing i need to know is do i have to connect the cross over pipe and cam cover vent pipe back up b4 i crank the car ?

[ex-static]

Not sure about your main thing.. but with the plugs, when it was running rich and sh.it like you said in anotehr post it could have fouled your plugs?

[Mick]

Hopefuly it didnt, but i wont know till i rip em out.

Preferably dont wana rip em out till i know if i have 2 connect all plumbing and pipes back up ..

[Mick]

Can someone please help me.

What i need to know is when i do the compression test can i leave the crossover pipe (IC to Throttle) off when im crankin the engine.

Because if i have to do it with it connected it will be hard to get the tester in ..

[turbomad]

Yeah I'd say leave it off because the engine doesn't have to actually start to test compression, just crank I think.