2001 wrx low vacum

[raymong]

reads 8hg at idle

seems like running on two cyclinders.not much power..

undone the spark leads on passenger side and no difference in engine speed

so what should i check??at first there was cel but then after afew starts and undone battery it done show anymore

[WRXONP]

check the spark plug bro...might be farked... has it got coil on plug or the coil on top?

[Guest]

Cambelt timing if two cyls on the same bank have no effect on running condition of engine

So very unlikey coils/ coil pack or spark plugs

Or if it has AVCS - Oil filter basket has slipped into the AVCS valve, remove banjo bolt and remove carefully if this is the case

[raymong]

i checked cam timing over when i done the cam timing to make sure it was right..

where is the avcs location?

[Guest]

above inlet cam - will be a valve with wiring going to it and a banjo bolt going into it for the oil feed (if its fitted ) - let me know

[raymong]

i had a look does not have avcs thanks for the advice

i also double checked the sparks again...took off the driverside leads and started it..and it started so its nothing to do with it..so its running on all 4.

what i did was got a short block 2nd hand and bolted my heads onto it (the last owner got a rebuild apparently....she was knock knock knock..thinking it was a big end bearing....so stripd it and reassemble and so on...

didnt look much into old block..it was at work and today my other workmate had a look...and holly sh!t !!3 old style valve recese pistons and one v7 piston!!!!!!!the v7 piston was sticking out 1mm!!!the block was a ej20r.....mmm

went to bolt on flywheel and the engine wont move~!!!???? the flywheel had been lightened and the back face was flat!!!!they "GRIND" the ribbing on the block to make it fit!!!

havent got the receipt or found out the 'engine builder' yet but oh dam they better get shut down!

only got it running last nite was quite late so didnt go much further

after work today done somemore checking made sure all fluids were good and no leaks. took for a drive out the country didnt thrash it just to put some kms in and see wat it ran like

its got a lumpy idle and low vacum..hesitates at low rpms and seems lack of power down low...as the revs go up it runs pretty smooth and power is not too bad running factory boost 7psi with vf28, no smoke and oil bunning so i doubt it be rings making it low compression =which mite lead to low vacum.no oil in water or water in oil..not using water so no head gasket leak either...certain the cam timing was fine as i double checked when i put the cambelt on..what would car run like if the cam timming was out?

i did remember that i ripped one of the inlet mani gaskets and i jammed it with silicone ...so im pretty sure thats the problem ...low vacum usually means a leak after the throttle body and i couldnt find anything unplugged..

will get some new inlet mani gaskets and hopefully it will solve the problem

[Guest]

Your discriptions over the net make it WAY TO HARD to diag

You first discription was - running on 2cyls - Anyway.........................

Factory boost is not 7psi ! thats wastegate pressure only, so either plumbed wrong or in fail safe mode

Low vac can be either a leak - or mechanical issue

incorrect cam timing WILL give low vac

you should have 18-20Hg with all electrical loads off

spray some crc around the intake gasket area, if its leaking there you'll soon here it

good luck

[raymong]

double checked the cam timing today...was fine..

replaced the inlet mani gaskets..

done compression test all above 150psi...

checked all piping and all hoses...

still low vacum...

any ideas?

[raymong]

checked spark plug gap was fine

still has the lumpy idle...

[Guest]

inlet and exhaust cams around the wrong way?

[WRXONP]

LOL i would deffo laugh after all this hasstle if it were just a simple vac leak on the manifold ie vac hose / could even be boost gauge...

a vac leak will allways make low vac and allways make it run like ass

[Guest]

Yip indeed vac leak would be funny - esp if the boost gauge has been installed on the map sensor line

[WRXONP]

hahaha yeah anything like that aye...or just a perished vac hose on the fuel reg or something....

[raymong]

when i stripped the engine i made sure i had the camgears back onto the cams so no mix up there.

i didnt think it would make the compression with the cams around the wrong way?different durations on the cam lobes would make it have alot less compression?

i will do a recheck on the leaks...i do know the boost gauge is not in the best condition(tee into the bov line)but the car defitnately not running right...its doesnt hav the same rumble compared to other subys i have owned..are the v7's different or something??

will check hoses again 4 perish or holes

[WRXONP]

well the rumble is dependant on what exhaust u have LOL not the motor it self...

u should really have the boost gauge on its own nipple if possible... but having it on the blow off valve wont make it loose vac...

will be running rich as if it has a vac leak

[Guest]

EJ series engine WILL run with camshafts inverted , with rough idle and det under load

[raymong]

well it just doesnt sound right to me..

the v7's dont have many vacum ports. port on for bov,brake vacum, fuel pressure reg,and one for the fuel emissions

spark plugs were black..

[WRXONP]

black = rich (obviously)..urv either got a leak on the manifold or could it be a faulty brake booster? leaking diaphram or something silly like that??

do u run an o2 sensor?

[raymong]

could be faulty brake booster...runs o2..

how hard to tell inlet to exhaust cam while in the engine?

[raymong]

no det on load..

would they still comp test with cams inverted?

[Drunkenmonkey]

i have had boost guages read low on BOV line..

WHY i have no freaking clue but once changed to own port or wastegate line read totally different

[Guest]

 raymong said:

no det on load..

would they still comp test with cams inverted?

YES, just puts cam timing out and they still have compresion

[Guest]

 Drunkenmonkey said:

i have had boost guages read low on BOV line..

WHY i have no freaking clue but once changed to own port or wastegate line read totally different

+1 on this, most aftermarket BOV leak on the vac side hence incorrect readings

[WRXONP]

 Drunkenmonkey said:

i have had boost guages read low on BOV line..

WHY i have no freaking clue but once changed to own port or wastegate line read totally different

wastegate line will read totally different (higher PSI) as it wont see the pressure drop through the intercooler etc...plus if the wastegate is on the turbo nipple it wont see vac at all

[Guest]

wastegate line wont see any more pressure than 0.5bar (typical opening pressure of wastegate)

WG solenoid bleeds boost off this line to raise boost