john banks

Thanks Carlos, it is a lot better at 900-1000 RPM which it runs if I set +300 RPM on Delta Dash. It will then idle at 14.7:1 which is nice because I don't need to do complicated circuits to turn off closed loop on idle only. It is still happier a bit richer though.

[Edited by john banks - 12/2/2003 6:50:54 PM]

john banks

As title - idles like a complete dog at stoich... It idles much nicer at about 13:1, but I can't run closed loop on cruise only.

Timing is fixed at 12 degrees and non-adjustable.

I will find out when I change to 740s if it is smoother - I wonder if one of my injectors is a little poorer flowing than the others?

I expect the lightened flywheel and stiffer engine mounts transmit more vibration.

I might try increasing the idle speed also.

Comments/input welcome.

scoobyslut

Ever thought the lightened flywheel may have upset the rotating mass figure, required to maintain over the non powered strokes?
Your only way is to raise the idle rpm to possibly even this out.

Bob Rawle

Sounds as though the injector timing is not suiting the better VE you have with the different engine, should idle just the same given that is correct.

carlos_hiraoka

Just raise your idle speed to 900 rpm, that should sort it out.
Bob .... did u get my email ?????


Carlos H.

john banks

Idle vac is only -6 PSI. Need to check for leaks.

I didn't notice it being anything other than -9 PSI when it was running the slower idle, but I'll need to check tomorrow.

carlos_hiraoka

idle vacuum should be between 7 - 8 psi.

Carlos H.

john banks

Can't find any obvious leaks by torchlight. If I pull a hose off there is an obvious hiss and loss of idle quality.

I'll need to see what it is on over-run also - IIRC that runs quite a lot of vacuum usually.... from a log I have of a lift off it only goes to -6 PSI though.

Will check the dump valve. Can't hear or feel anything around the inlet manifold gaskets.

carlos_hiraoka

could it be that you have less vacuum since you are idling higher ?????

Carlos H.

john banks

Could be I'll double check by dropping it again, but from a log of a lift off at high RPM on full load, it only goes to -6 PSI also

carlos_hiraoka

could it be because you are using non-stock cams ?????

Carlos H.

AlanG

I think the cams John is using are he std Sti Ver5 ?

What about cam timing being out though? If it's a tooth out on the inlet cam, this can affect idle quality and vacuum reading?

Alan

jgevers

Hi John,

Low inlet manifold vacuum with no air leaks point towards cam timing being wrong. What are the exhaust gasses like? If you run 14.7 according to ecu, this should reflect in the gasses, eg lambda 1 etc.

Pop in for a coffee.

regards

Job

john banks

Thanks to Job with his vac gauges ... there was a small leak on the valve before the charcoal canister.

Pavlo

Andy.F

Did that just affect the gauge reading then, not the true vacuum ? The ISCV would just adjust position (within reason) to maintain correct idle speed regardless of leak.

Andy

john banks

Just the gauge reading not the true idle vac because the leak was off a small branch that also feeds the boost gauge and MAP sensor.

Just fitted 740s and it is idling far smoother at 800 RPM and 14.7:1. Also revs a lot cleaner. Interesting...

jgevers

Hi John,

What are the spray patterns of the 740s like compared to the others?

It would be interesting to check the current ramps of both types of injectors when the ecu switches earth to open them.

regards,

Job

ustolemyname??stevieturbo

iTrader: (1)

That same valve went on my car a few years ago. Car drove fine though, only thing I noticed, was my boost cut had dissappeared.
Couldnt figure out why, as there were no obvious leaks anywhere.

Andy.F

There's a thing JB Wouldn't that leak also drop your gauge reading when on positive boost ?? Perhaps your extra torque can be attributed to running 2.5 bar boost

Andy

STi M'8

Can anybody explain/show what is subject charcoal canister valve ?

I think I have a similar pb on my 8...

T-uk

boost was interesting tonight after he pinched the valve off my car

john banks

Indeed Andy, you have the clincher, the boost appeared to increase (with no adjustment) after the valve was replaced but with no improvement in torque or power to speak of, but I think it was always 1.35 bar, with higher peaks up to 1.54 bar when thrashed hard.

Despite fairly rich mixtures the EGTs reached 917 pre turbo when the brain was put in the glovebox by T-uk, 880 when I drive it This is apparently a bit high for these pistons.

Needs some thought. I don't want the faff of water injection in some respects, but I think I'll have to to cool the EGTs.

COPY POSTED IN PROJECT THREAD