Need more help with knock issue

[Norcalrallyist]

Ok I have figured out that the knock is not caused by external mechanical noise IE lifters. What I did was take the wastegate arm off. So under 0psi WOT through all gears I didnt get 1 single knock count. Now what should I do to fix this problem? I have new plugs wires and im running 5btdc with timing grounded and super unleaded. It knocks under 10psi as of now.

 

[bastarddsm]

u'm what heatrange plugs u runnin? how many miles do you have on your car? it is possible that your combustion chambers are all carboned up and causing it. do you have your plug wires on correctly? how do you know that u have your timing set correctly?

 

[kpt4321]

Did you get zero knock all the time with no boost, and do you now get consistent knock with th boost back on?

 

[Norcalrallyist]

Yes I get absolutely no knock without boost and in the 20s with 10psi. I dont know the heatrange of my plugs I just got autolites for the 90 gst. I know my timing is right, 5btdc just like the manual says grounding and all. Ive got 160k miles on it or so. And my plug wires are on *Spark**Spark*. :laugh:

 

[kpt4321]

Sounds like real knock to me. I bet you have a fuel delivery problem like a clogged injector, a clogged fuel filter, or a bad pump.

Either that or your knock sensor is simply dead.

 

[Norcalrallyist]

Cool thats what I was thinking I would try next.. I am running the injector cleaner stuff to see if that will help and im going to change the filter this weekend. I guess ill replace the pump after that.. Im sorry i didnt mention this but I replaced the knock sensor with a brand new one.

 

[bastarddsm]

How do you know that u are at 5 dbtdc the marks? the marks don't meany anything. Pull ur plugs and use a long screw driver in the number one hole and turn your motor over by hand untill the screwdriver stops moving that is close to tdc. Theres about 5-10 degress of free play in there, but make sure your marks are close. Also make sure your cams are in time. If all that is good then go out to a local country road and make a pull. Run it where it knocks for a while. Then push in the clutch and shut it off quickly coast to a stop and pull the plugs. Take a second set with you. Take pictures of your plugs and post them so we can see them, or take to a competent race car tuner ( not some schmoe that slaps a cai and a fart pipe on and calls it tuning someone who has built a car that has gone fast like 10.00 or better) and have them look at them. If it really is knocking as bad as you say then it will show up on the plugs. They will look burntish, If they have and aluminum depsits on them u are definatly detonating.

are you usure your only running 10psi not more what kind of gauge you have?

good luck kurt

 

[Norcalrallyist]

Actually I am using the timing marks. I have a whole page of things Im going to see if I can check into this weekend. I was going to buy some better plugs but what heat range should I get. I was thinking of getting some NGK plugs but I dunno what im looking for as far as heat range goes etc.

Heres my to do list for this weekend:
Check cam gear alignment
Check timing cover vs tdc (thanks I hadnt thought of this one)
check plugs
replace plugs
clean injectors
replace fuel filter
check ecu for leaky capacitors

As far as getting pics I dont have a digi cam but ill see if I can get a hold of one from someone

 

[bastarddsm]

the first thing i would do though is check the plugs they shoulc all be relativly the same color a tanish color if one is really white and burnt looking then you might have a fuel problem.
um i am not sure on the plugs but i do know for a fact that in NGK's the bigger the number the colder plug it is. for example a b7es is hotter than a b8es. Um i would drop one heatrange. i think our cars take like bpr6es i would go with a bpr7es. If you really need to get technical on finding tdc get a degree wheel and use it to find tdc. If you plan on ever getting adj cam gears youll need it anyway. also when use check your timing use a dial-back timing light.

Sorry if i am pointing you in manny different directions, but it is hard to diagnose a problem over them web.

 

[Norcalrallyist]

everything lines up perfectly. The plugs look normal except for the fact they have been fouled by MMT that i have been running the last week to clean the injectors. I just took the injectors out and pumped a bunch of cleaner through them off the car. I am using a timing light that you can set advance timing..

 

[bastarddsm]

anything changed??

 

[Norcalrallyist]

I broke one of the o rings on the injectors so i had to wait to put it all back together. So I replaced the fuel filter bench cleaned the injectors off the car. Hmm got some new ngk plugs and threw them in for good measure and ran some injector cleaner in the tank. I still have a knock under WOT around 10 counts. Im going to take the ecu out and inspect it tomorrow but I doubt ill find anything. I have no idea whats going on with this pile.

 

[bastarddsm]

test the knock sensor. start the car with the timing light on it and the pin not grounded. strike the intake with a hammer trying to imitate knock and see if the computer changes the timing.