I think im chasing a ghost!

[OneFastBaron]

Hey everyone, i have got a 88 turbo lebaron with a 2.2 TI with a garrett TII turbo and intercooled, with a 3bar TU cal, with all the supporting mods, +40% injectors, afpr, big NPR intercooler, and so on. i also just recently swapped it over to 5 speed. i am running around 22psi and i think i am chasing a ghost. i hooked up my OTC4000E to it today to data stream and see if i am getting any knock retard. i have data streamed before on this calibration with it in my other car and it ran great at 29 pounds with the base FP set at 57psi. no knock retard. basically this is the same car minus a forward motion E2 turbo and a ported head and manifolds. this car is showing the knock retard is on and its pulling timing from cylinders as much as 14 degrees i have seen WOT. (i tried lowering the boost all the way down to 10psi but the same result) but the knock voltage doesn't make sense. because it will only go up to about .8v at most. and if i am under a slight load 2-3psi it will show its pulling timing on multiple cylinders up to 5 degrees. even cruising sometimes it will go to knock activity "yes" and pull a degree out of a cylinder. it just doesn't make any sense. i tried swaping knock sensors from my other car which performed fine and it does the same thing. and if i disconnect the knock sensor of course it shows 0v and no knock activity at all. even just idling at 900rpm every couple seconds it will jump to .08 for a second then go back to zero. the spark plugs look great (RN9YC gapped at .028") and the car seems to run fine. regardless if its showing knock activity and pulling timing. i tried tapping on the intake manifold with a hammer with the car off key on to see if it would show value, and it doesn't show anything no matter where i hit it on the intake, even right next to the sensor. and i know this cal isn't junk because it never did this on my other car. i am just pretty stumped right now and looking for some input.

Thanks
KJ

[chilort]

I've heard that knock sensors are sensitive to how much you tighten them. I believe the proper torque is around 200inlbs. Might try that.

[OneFastBaron]

I've heard that knock sensors are sensitive to how much you tighten them. I believe the proper torque is around 200inlbs. Might try that.

i thought that too, so i did use RTV on the threads (read that somewhere that it could help) and didnt torque the hell out of it turned it till it stopped. but still, the same problem.

KJ

[OneFastBaron]

anybody?! i am trying to get this sorted out before the track friday.

Thanks
KJ

[vcrpro3]

i thought that too, so i did use RTV on the threads (read that somewhere that it could help) and didnt torque the hell out of it turned it till it stopped. but still, the same problem.

KJ

RTV?? It's an electrical insulator and its rubber properties may be dampening the knock sensor mechancally. I think the sensor has to be grounded electrically to the manifold. If anything, metallic antiseize is what i think should be used ( of course i am probably wrong)

[OneFastBaron]

RTV?? It's an electrical insulator and its rubber properties may be dampening the knock sensor mechancally. I think the sensor has to be grounded electrically to the manifold. If anything, metallic antiseize is what i think should be used ( of course i am probably wrong)

yes, i only used RTV on the threads, i know its grounds through the intake manifold so i didn't rtv the flat that seats down onto the intake manifold. so it is still grounding. i figured it wouldn't hurt to try.

yesterday i even pulled the wire off the knock sensor to see if i could get it to audibly detonate. i heard nothing even at 20psi (yeah i know i am crazy like that with no knock sensor at 20psi )

so today i decided to swap back in the 2 bar computer stock injectors and 2 bar map. same result, it kicks the knock retard on at a cruise under a very slight load. maybe 1-2psi indicated on the OTC and boost gauge, stock mechanical gauge and on my electric (greddy profec b). and what it would pull 1-2 degrees out of a cylinder, mostly cylinder 4. i don't hear any knock at all (keep in mind i have a very quiet exhaust on this car because its my daily driver).

anyone?! i didn't go to the track because of this.

[t3rse]

replace the knock sensor and check for loose motor mounts, and don't use RTV this time

[OneFastBaron]

replace the knock sensor and check for loose motor mounts, and don't use RTV this time

i did replaced it and tried it with and without the rtv. didn't make a difference.

KJ