Low comp over all cylinders (3tgte)

[Radar]

Ive been getting readings of -- 100psi #1 - 79psi #2 - 74psi#4 (intercooler pipes in the way of cyl 3)

I checked my valve clearances to find I only had .004in clearance on the intake, unlike the .010in the book suggests.
The exhaust had the proper .012in clearance..
So my question is are my shims to big in the intake and not letting the valves close?

[oldcorollas]

if you have clearance, all the way aroudn the base circle, then the valves are closing, at least at the temperature you measure

with low figures, mayeb the cams are out by a tooth? or maybe it is rings?

check your cam timing 3 times, then get someone else to check

[lexsmaz]

How does the car run ? with readings that low & that much difference betwen the cylinders it would run very poorly & quite rough, does it run like its way down on power ??... Have you tried another comp gauge ...

[MWP]

Was the engine hot or cold when you did the compression test??
If it was cold, having a small valve clearance like that wont matter, and wont be the problem.

Did you hold the throttle open when you did the test. Lots of people forget to do this.

Did you do a wet compression test?
What were the results?

[pandaah]

yeh something sounds a little wrong with those figures.. id actually be quite suprised if it ran properly when it was hot..

[Radar]

God no it doesn't run well but yes it does run.. It is massively low down on power, has a persistent misfire and the injectors are set to 130cc out of 295cc..
My mechanic mate did the comp test for me, he suggested a wet comp test which I'm yet to do.
It just didn't make sense that all 4 cyl's were low so I thought that it might be the valves... I'm now thinking its prob the rings..

[MWP]

... and the injectors are set to 130cc out of 295cc.

What the *** does that mean?

[Draven]

maybe he means 45% duty cycle?

I wish you could set the cc on injectors... that'd be awesome.

I'd double check your timing as well, jumping a tooth creates your symptoms, and is a lot cheaper than rings

[oldcorollas]

and a lot easier to check

[Radar]

By smaller injector size I mean overall fuel calc multiplier has been set accordingly ...
8.112 x D / I
D = Cylinder volume
I =Injector flow rate @ operating pressure
So instead of the 295cc that they operate at i've done the formula with only 130cc
When the formula is done right with the injectors set at 295cc the motor just barely fires and the O2 sensor has a field day thinking its running massively rich..
But with the when you change it to 130cc the motor sits there and idles a lot nicer (still shit but nicer)

Skipped a tooth? Now what do you mean here? I set the cams back to factory 2TG settings (I have the factory repair manual for the 2tg) So basically the notches in the cam are inline with the markers on the bearing caps

[pandaah]

i think he means if you have a timing belt.. pritty uncommon for a timing chain to jump without damaging something..

[oldcorollas]

no, i think the meaning is incorrect assembly.

the marks might line up, but check the actual cam lobes. check clearance aroudn the whole base circle too. sometimes cam base circles are not even.

are they stock cams?

74psi is pretty crap if it is only due to rings.
does it blow smoke?

[Radar]

Stock cams (different shims I'm told) and nah not smokey.. The guy who owned the motor before me set the LSA in some wild position on a 5th hole that was hell far away from the 4 on the timing gear.. So the old man and I followed the manual and put it back to where we thought was std... So maybe the intake cam still isn't in the right spot?
Keep in mind he said this has 7.5:1 forged pistons in there so the comp could well be a lot lower than that..