Markus951

Hey Guy's

I have problem to tune my car.. I checked to spark plugs and I am running lean on the last cilinder (the one witch is closest to torpedo wall..) in the first cilinder I am big big rich, the cilinders in the middle are sort of rich but not big ritch.

Spark plugs look:

1 -big big rich..you can see wast of unburned fuel oil there...
2 - blackish
3 - blackish
4 - coffe brown..

I have now tested my injectors in the special Bosch testing equipent and in 10 000 rpm they where equal..

Could it be that this is due to the poor design of intake manifold?? that I have a lot more air in the last cilinder because boost will enter this runner first and the others later

I am running full standalone engine management..
My injectors are 720cc
Garrett GT30R 1.6 bar boost
Stock fuel rail
Walbro 255lph fuel pump
9mm bigger throttle body with was installed a little up from the centre of stock TB location. The throttle body I have works the opposite to the porsche original one.

Also I had to port my intake manny to make the 9mm bigger throttle body..


http://eku.3lite.ee/albums/Orange-Be...IMG_9096_1.jpg

Rogue_Ant

This is a quote from Lindsey Racing:



Rogue

Chris White

I would look at the engine management set up. Are you running full sequential or semi batch fired? Many systems run in semi batch mode which links cylinders 1&4 and 2&3.

I don’t have any problems with the stock intake on lots of highly modified engines.

Chris White

PS – Oil consumption can cause similar reading too.

Markus951

My car consumes oil! Even after rebuild. How the oil consuming can affect mixture in cilinders..

THe first cilinder is the ugliest (richest on those) and this is where I changed the sleeve. I used porsche original sleeve witch is also made of aluminium. The whole block was treated with alusil when I did rebuild.

I have now noticed after 5000 km When I turned engine to TDC while sparkplugs where off it was really hard to turn it around. Also when I changed the valve springs i did on the method where you press air to cilinder to keep the valves up during the process. When I did it the engine did not move AT ALL. even with 8 bar to the top of the piston it did not push it down..

While I was on the dyno I saw from oil catch tank witch is wented now to atmosphere that its guite a bit of pressure what comes out form the tank. You can even see the smoke'ish flow with your own eyes.

My oil pressure stays at 3.5 bar @ idle, even when it warms up and gos 5 bar on running.

markus

xsboost90

sounds like #4 is the only one running right!

fast951

Do a leakdown test to figure out where and if there is a mechanical problem. Now look into your engine management and wiring.

The factory intake manifold will not cause the problems you are having. Of course, make sure the intake gaskets are in place, functioning properly and are "installed properly".

hosrom_951

Right, plugs should read light grey/tan-ish

Are you certain that the #1 pluh is not fouled by oil and not fuel?

special tool

nothing wrong with the stock manifold.

I have 1 EGT probe in EACH exhaust port - they are within 40 degrees F of each other - always.

Chris White

I agree with tool....same EGT readings.

toddk911

How does oil getting into the cyl. affect the spark, a/f, performance, etc. ?

Markus951

I did the pressure test in cilinders with open throttle

it showed
1# - 8.3 bar
2# - 8.5 bar
3# - 9 bar
4# - 8.5 bar

I also noticed that engine is really hard to spin around when spark plugs are off.. ( i mean the starter should push it faster) also when I changed the valve springs then i put the pressure into the cilinders, the pistons where not pushed down in any case.. and I had some really small whine in crank wentilation while I did it..

can it be valve seal(s) or turbo what presses the oil into cilinders but all of it will go to first cilinder because its the closest to throttle body?

Markus

Duke

Pressure test as in compression test??

hosrom_951

Those numbers are dang low for a rebuilt engine, i got those numbers with a closed throttle, an open throttle got me to the 143+psi range (9.85bar+)

Oil on spark plugs are usually from valve stem seals, especially when the engine is turned off and the next day you pull the plugs and find some oil (oil leaks into the combustion chamber while the oil is draining from the cam housing). If you pull the headers and find oil, that's definately valve stem seals, but they have nothing to do with compression numbers.

Markus951

yeah its a compression test and i did it with cold engine, not warm

Could it be that the piston rings have not sealed yet? I have done some 4000 km after rebuild..

That still does not explain the oil consumption. The compression test show'd different..there are now cilinders what are alot worser than the others..

M

jacklet

do a leak down test-it will give you better insight as to where your losses are