GN with knock?

[1BadassGN]

hey guys im new here but im over on turbobuicks.com i posted i have been getting ALOT of knock from my EMC-10 (old school as hell) but the knock sensor/light/beep. has progressivly gotten worse today on my way home i got into boost and it almost continually beeps once i pass 9 psi

i checked my FP and it was like 53 with the line on and 62 with the line off. i believe thats a TAD high i do have a adjustable fpr. cars only boosting 14 psi (spikes 15) and it sounds like i have marbles in the engine. im going with my gut that thats spark knock (possible detenation?) what to do?

someone said to lower the fuel pressure to about 40?

 

[azbob]

The fuel pressure should be 42 with the vacuum line off. You need to be careful and not go to "marbles sounds" unless you just need to rebuild the engine.

 

[bmackinnon]

you have the fuel pressure cranked up way too high, and now the pump is failing.... new fuel pump and set the pressure to 43 psi line off.... and go from there... REPEAT.... NEW FUEL PUMP NOW!!!!!! or get ready for a rebuild... you can convince yourself by hooking up a fuel pressure gage with a hose and taping it to the windshield so you can see it while driving.... watch the pressure go up as you start getting into boost and then fall off a cliff..... dead pump...

PS - the 'marble sound' IS detonation, and the result inside the combustion chamber/piston tops is the same as if you really did have steel marbles in there...

 

[1BadassGN]

you have the fuel pressure cranked up way too high, and now the pump is failing.... new fuel pump and set the pressure to 43 psi line off.... and go from there... REPEAT.... NEW FUEL PUMP NOW!!!!!! or get ready for a rebuild... you can convince yourself by hooking up a fuel pressure gage with a hose and taping it to the windshield so you can see it while driving.... watch the pressure go up as you start getting into boost and then fall off a cliff..... dead pump...

PS - the 'marble sound' IS detonation, and the result inside the combustion chamber/piston tops is the same as if you really did have steel marbles in there...

very much appriciated i will adjust pressure tomorrow and get a pump before the end of the weekend i want to do the supra pump i think but idk i havnt seen enough info on it to try it myself. anyone can help me out are the connectors the same etc etc?

 

[Hacksaw]

X2!!

Also, too rich an A/F ratio, & carbon WILL build up, causing detonation. You have too much idle fuel pressure there. Even with an O2 sensor, it can be way too rich at idle & low speed.

1. Get a NEW fuel pump, and set the regulator to ~42 with the hose off idling. I have no info on the Supra pump.

2. Use a decarbonizing cleaner. If you get detonation with 91+ octane at only 9 pounds of boost, something's wrong!!

 

[1BadassGN]

i work at a chevrolet dealership i cleaned the injectors and did an induction service to clean carbon and cleaned throttle body and 93+ octane at all times with some additive once and a while and im going to get a fuel pump and take it down on the fuel pressure

 

[bmackinnon]

search 'supra fuel pump' and you will get all the info you need, and then some! :wink:

 

[Razor]

hey guys im new here but im over on turbobuicks.com i posted i have been getting ALOT of knock from my EMC-10 (old school as hell) but the knock sensor/light/beep. has progressivly gotten worse today on my way home i got into boost and it almost continually beeps once i pass 9 psi

i checked my FP and it was like 53 with the line on and 62 with the line off. i believe thats a TAD high i do have a adjustable fpr. cars only boosting 14 psi (spikes 15) and it sounds like i have marbles in the engine. im going with my gut that thats spark knock (possible detenation?) what to do?

someone said to lower the fuel pressure to about 40?

get a proper scantool like a scanmaster2.

get a proper chip made for your injectors

Set fuel pressure to chip recommendations and watch long term fueling on the scantool(BL) to make sure things are where they need to be.

Put in new walbro fuel pump and be done with it. keep it simple stupid KISS

cars are easy.. just need the correct guidance.

And yes keep it out of boost until the above is done. I bet the oil is also trashed from running wrong fuel pressure.

 

[bmackinnon]

Put in new walbro fuel pump and be done with it. keep it simple stupid KISS

That would be my recommendation also.... unless you are shooting for low, low 11's in the 1/4, the walbro is plenty 'o fuel.... a hundred bucks, slap 'er in, and done.... the KISS principle...

 

[1BadassGN]

ok so my main thing is WHAT is causing this what acdelco spark plugs does everyone use i wanna make sure i got the right ones. car seems to break up in 3rd gear and its sluggish

 

[bmackinnon]

ok so my main thing is WHAT is causing this what acdelco spark plugs does everyone use i wanna make sure i got the right ones. car seems to break up in 3rd gear and its sluggish

What is causing this??? Isn't it obvious?? The car is going BAD lean due to failing fuel pump/dropping fuel pressure, and detonating like hell while the ecm is pulling all the timing out trying to save itself from destruction.... which it won't succeed at if you keep beating on it...

AC Delco R43TS or better yet, the heavy duty commercial CR43TS, gapped at a tight .035"