Knock Knock Knock at 10PSI!

[jfdid]

Logged for about 15 mins today. Bear in mind this is on about 88 octane pump gas.

At 15PSI, i was hitting about 24 on the knock count...ouch. Timing was poor, down to like 4 or something.
Lowered boost, 13 PSI...still 20 on the knock count at high rpm(about 6000)
Boost lowered to 10 PSI, I hit a max of 14 knocks. This is on STOCK BOOST?
My Medium and High Fuel Trims are both maxxed at 119%(it's a 1990)

Every once in a while, just cruisin at like 2500 RPM, the knocks will go up to 43 for a couple of seconds? Any ideas?

My lifters aren't new.
I still have stock injectors, running a 16G turbo, stock everything else pretty much.
Any input is appreciated

 

[crankbender]

From the manual for YOUR car.

"Your car will operate satisfactorily on premium unleaded gasoline having a minimum octane rating of 91....."

Get some good gas in there and try again. If the problem persists with teh correct gas let us know.

 

[jfdid]

, I figured that was coming. I forgot to post. "I'm gettin some better gas at the next fill up, I'll post more results!"
Thanks, and sorry for being a retard!

 

[GSXanimal]

It also wouldnt hurt to reset the ecu after you start running the higher octane.

 

[talon1979]

If I put anything in my baby that is less than 91 she will lift her rear tire and pee it back out on me .

 

[jfdid]

Threw some 91 octane in there. At 10 PSI, no knock, so that's good. Brought the boost up to about 14 and I'm still hit hittin 20 on my knock count.
I have a rewired fuel pump.
Does this sound like phantom knock? I'm thinking not because it is clear at 10PSI?!

Time for a fuel system upgrade I suppose?
Any ideas about the 43 knock count out of nowhere?

Thanks guys

 

[OverboostXS]

Im not really that technical but this happened to me so i'm just throwing it out so be gentle if i say it wrong, but the lifter chatter i believe was causing my "ghost" knock and after my head rebuild the knock was gone. So it might just be that or not. Glad I can be of little service.

 

[ITSME4G63]

Originally posted by jfdid
Threw some 91 octane in there. At 10 PSI, no knock, so that's good. Brought the boost up to about 14 and I'm still hit hittin 20 on my knock count.
I have a rewired fuel pump.
Does this sound like phantom knock? I'm thinking not because it is clear at 10PSI?!

Time for a fuel system upgrade I suppose?
Any ideas about the 43 knock count out of nowhere?

Thanks guys

Isnt 43 counts of knock the max the knock sensor can count?, My friends talon had 43 counts of knock at wot and before tunign Ive even seen 43 counts of knock and Ive seen countless threads where people got 43 counts of knock.

 

[Vandy4g63]

How much 88 was left in there when you filled up with 91? 91 is the bare MINIMUM you can put in the tank...I recommend either drivnig around with no boost for a while and re-filling up with 91 or putting an octane booster in (to be safe) and driving around with no boost until your next fill up. YOu're lucky you didn't do any serious damage trying to boost at 15psi on a 16g with 88 octane gas....take it as good luck and give the poor girl a rest for a week until you get good gas in there...

 

[jfdid]

THere was minimal 88 left in there. My gauge light was on for about 40 kms or so. As far as the 43 knocks...yes it is the maximum reading...and it wasn't at WOT which is why it didn't scare me as much. 23 knock is still a hell of a lot, so I'm at 11 PSI with no knock until I pick up a MAF, MAFT, 550's and 190lph. Thanks for your input guys.

PS. Nobody knows why when I'm at like 1/8th throttle, crusing at 2300 RPM, my knock count just goes up to 43?

 

[chinchin]

If I had to guess I'd say it was the timing. Have you checked that? Probably be a good Idea. Alot of times these backyard garages dont know anything about certain things that you have to do to check timing on these cars like grounding out that lil connector above the battery. So check the timing then check back w/us.

 

[jfdid]

Sounds good. Will do. I'll go grab a timing light in the next couple days and get back to you.

 

[titogs95]

please let me know! I am following you!
I always use 91 or 93octane of fuel.
Seem that I had to lower my boost to 10 and still i have 5 sum knock on WOT. but that is nothing compared to the fact that I have really high knock from 2000 to 4000 rpm. it is annoying and kill my ears (the datalogger has an alarm for it. I won't disconnect the alarm because i am afraid that something else might happen.)
Anyway mine is knocking really high at low RPM, on closed loop.
TIA
Tito

 

[Nautica985]

PS. Nobody knows why when I'm at like 1/8th throttle, crusing at 2300 RPM, my knock count just goes up to 43?

I have the same problem. My TB shaft seals leak so its either that or phantom knock. check for boost leaks.

 

[KAOTIC95gst]

when my motor is cold i get knock at low rpm and around 30-40% throttle that is when i have the knock sensor start working on dsmlink and the knock is from my lifters. so i would say that your low rpm knock is from your lifters.