engine lacking power

[3.0 GT]

ok, i just rebuilt the engine and it had a 2.0mm mhg on there(1.7mm mhg would have kept stock compression). it ran nicely, timing 10 degrees BTDC, except befor boost i could feel a little power loss in the low end (due to lower compression ratio) but overall it ran nicely. decided to swap headgaskets with a 1.6mm ish mhg to bring back that low end, before boost, power(compression a little higher than stock now). but now the car just feels slow. even with boost it sucks. my dads FJ couuld prolly beat it. at first i had my knock sensor wires fucked up so i fixed that and code 52, which brought back some power, but its still slow. i didnt move the cps so my timing should be the same but i cant check til monday. where should i start? pretty sure no vac/boost leaks. new airfilter too. i put some platinum(two electodes) spark plugs in while i did the head gasket but idk if that could be a problem, they said not to gap them. wires i think are good. any help would be awesome.

Also, what holds boost in the manifold instead of going back into the crankcase/accordian hose via the pcv system?

 

[steven89]

Did you make sure to check that the cams were TDC along with the crank before taking the head off and putting it back on?

 

[jdub]

The TB has an orifice built in the PCV fitting:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=5

It needs to be clear for the PCV system to work properly.

 

[3.0 GT]

Did you make sure to check that the cams were TDC along with the crank before taking the head off and putting it back on?

The TB has an orifice built in the PCV fitting:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=5

It needs to be clear for the PCV system to work properly.

yes the cam timing is correct, it was first thing i checked.
and does the pcv system have a check valve in it somewhere so positive prerssre doe not go back out?

 

[jetjock]

There is no check valve. Nor do you want one.

 

[3.0 GT]

There is no check valve. Nor do you want one.

so does boost just go through there and back before the turbo?

 

[jdub]

An orifice is just a pin hole...under boost it creates a venturi effect across the top of the valve cover ports and assists moving crankcase vapor to the accordion hose. It's not very efficient, but it's also a small percentage of time the motor is in boost. Most of the time crankcase vapor is pulled through the TB orifice under manifold vacuum.

 

[3.0 GT]

An orifice is just a pin hole...under boost it creates a venturi effect across the top of the valve cover ports and assists moving crankcase vapor to the accordion hose. It's not very efficient, but it's also a small percentage of time the motor is in boost. Most of the time crankcase vapor is pulled through the TB orifice under manifold vacuum.

ok, but where should i start to look to fix my power loss problem?

 

[jdub]

Check timing.

 

[tlo86]

whats your compression look like now?

 

[IJ.]

Timing

Valve lash

 

[3.0 GT]

Timing
will do asap
Valve lash

valves were adjusted when the motor went in to the car, recently

whats your compression look like now?

havent checked but will do.

 

[jdub]

New engine - you want to check valve lash and timing belt tension at the 500 mile point. Things do "settle in".

 

[grimreaper]

^ yes yes, valves may take a bit longer then 500 miles though...

hook some gauges up, your ass dyno is worthless in diagnostics. (sometimes mine feels superb, other times it feels the mcflurry from mcD's) One feeling/smeel/taste to one person is totally different to the next...

 

[3.0 GT]

New engine - you want to check valve lash and timing belt tension at the 500 mile point. Things do "settle in".

i guess ill be checking soon but im only at the 350 mile mark lol. almost there, but gas is exspensive.

 

[grimreaper]

so is the mkiiii

 

[3.0 GT]

so is the mkiiii

yeah i realized that, but im in debt too so fuck gas until then. i got a good job now so soon the bank will be risin

 

[3.0 GT]

yeah i realized that, but im in debt too so fuck gas until then. i got a good job now so soon the bank will be risin

well i checked timing and it was right on spot. so whats next? it has much less power to get up to speed than it should. boost makes it more powerful but it still sucks. it was more powerful before i took the head off. what does this leave me?
here is list of things i did,

-removed head
-swapped mhg from 2.0 to 1.5
-changed plugs to ngk platinmum(pregaped)
-fixed heater hose leak behind heat
-installed mechanical oil pressure gauge
-stripped block,headbolt, then helicoiled
-installed afm adapter to 3in cone filter
-reused egr and intake manifold gasket
-broke egr to manifold bolt, one of two,

put it back and bam! code 52. no power then. fixed code 52. a little more power, nothing to what it should be. timing st to 10*BTDC with diag block jumpered. ideas are running out. please help.

 

[jdub]

Time to check the valve clearances. I would never trust pre-gapped plugs...I always find one or two that the gaps are off.

What kind of head bolt hardware and what did you torque to?

Is the EGR leaking? The gaskets should have been replaced...that broken bolt, was it replaced?

I assume you cleared the ECU codes...are there any popping up now?

 

[3.0 GT]

Time to check the valve clearances. I would never trust pre-gapped plugs...I always find one or two that the gaps are off.

What kind of head bolt hardware and what did you torque to?

Is the EGR leaking? The gaskets should have been replaced...that broken bolt, was it replaced?

I assume you cleared the ECU codes...are there any popping up now?

plugs are the ngk double platinum that you are supposedly not supposed to gap. i am using arp studs tourque to 120ft/lbs with 30wt oil. no one in my are could get me some arp or similar lubricant.i dont think the egr is leaking but idk. the gasket is pretty shitty, and where it bolts to the intake manifold the lower bolt snapped. the threads are still in there, so air isnt coming through that hole, but it could be leaking air around it somewhere, i dont know if that would cause a significant power loss. and for codes. one time i hit fuel cut and code 34 and 52 popped up(after i fixed 52) cleared codes hit fuel code many times and never saw that code again. what i dont understand is why it had more power before the head was pulled and now its shitty!!! im pretty bumed