im suddenly getting knock and cant figure out why...

[thor'svr4]

my cars been running great all summer but recently it started breaking up under boost. so i did some dataloging and confirmed it was getting around 12 counts of knock at 16psi with the 13T's. According to my wideband i was at a 10.0-10.5 AFR (same as after ray dyno tuned) so im not running lean.

im not sure what could suddenly cause the car to start knocking.
the AFR is a little on the rich side, but ever since i installed the 8.5:1 pistons the cars always been tuned to around a 10.5:1 AFR. My ignition timing is right where it should be (6*), and retarding the timing has no effect.

Even if i lower the boost to 8psi i still get knock.

i know i need to get back on the dyno, but im not sure if it’s the tune that somehow got screwed up or if something mechanical broke. Anyone got any ideas of what to check next? the last thing i need is to drive all the way to Pampena motorsports for a dyno tune only to find out that ___ is broken and needs to be replaced...

[vr4tune]

Do you have adjustable cam gears?

[thor'svr4]

Do you have adjustable cam gears?

no i don't but was thinking of picking up a set of jack-hammer gears before i go back to the dyno. i checked the timing belt and all the marks are still aligned.

[Keyan]

2 things to consider:

if your fuel pump is dying, your ecu will still try to give you the best fuel ratio, but it means that it will have to call for higher IDC, which changes your ignition timing. So check your fuel pressure

and

check for worn spark plugs. may be misfires being read as knock.

[NOMIEZVR4]

boost leaks as well...

[thor'svr4]

2 things to consider:

if your fuel pump is dying, your ecu will still try to give you the best fuel ratio, but it means that it will have to call for higher IDC, which changes your ignition timing. So check your fuel pressure

and

check for worn spark plugs. may be misfires being read as knock.

ill put in a new set of plugs tomorrow after work along with a new fuel filter. how do you check the fuel pressure though? the only way i could think of would be to buy this Fuel Pressure Adapter Kit*-*Mitsubishi 3000GT*/*Dodge Stealth Parts

is there any other way to check the fuel pressure?

boost leaks as well...

i just pressure tested and there were no boost leaks

[Keyan]

a fuel pressure kit from craftsman, matco, snap on, etc.