DSMTalk Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum banner
Cancel
Create thread New Garage Forums

HOLY CRAP! 43 counts of knock on stock setup?

Jump to Latest
1 - 20 of 22 Posts
S

SM00TH976

· Registered
Joined
·
985 Posts
Discussion starter · #1 ·
i just logged my car today with my pocketlogger for the first time and i was getting way too much knock. at times it would get all the way up to 43 counts and just hold there steady. this of course was killing my timing. sometimes i could barely tap the gas and it would start showing a lot of knock. other times i could floor it and not get a single knock count. so i'm wondering if my knock sensor could be bad. the car has also started ticking at idle now too so i thought that might have somethiing to do with it, but it's not showing knock at idle.

oh yeah, the car isn't completly stock, i removed the lower honeycomb and replaced the air filter with a K&N and left the airbox off.
 
Discussion starter · #3 ·
well it was kind of a limited run. i logged RPM, knock and, timing. i also logged the O2 voltages on another run right after it. they seemed fine at around .88 give or take a hundredth. i have done a little bit of searching on this and it seems that 43 counts is way too high for it to be caused by actual knock. i think it may be the lifters and i'm gonna try putting in some good amsoil synthetic to get rid of the tick. if the tick is still there i will take out the lifters and clean them. if it's still there i guess i'll have to buy the 3G lifters. but apparently this whole phantom knock thing can be a bitch to diagnose. great.
 
Discussion starter · #4 ·
holy crap. i just looked at the O2 voltages on the second run. they dropped all the way to .14 at 2,843 rpms which is right around the time where the turbo spools up. the downward spike shoots back up and is completely level by 3,500 rpms. so there could actually be real knock, compounded by phantom knock. that sudden dip downward could be when i floored it. the timing took a slight dip down abot 8 degrees from 24 at 2,500 rpm to 14 at 4,530 rpms where it steadily rose back to 24 at 6,000 rpms.
 
Discussion starter · #5 ·
just did another log and i am getting huge amounts of knock under partial throttle. like in the 30's and up. but then when i floor it it's fine, i am getting zero counts of knock (shouldn't there be a couple of counts of knock?) i just noticed that there are quite a few times when the O2 sensor shows 0 volts. is that ever supposed to happen with the engine running? it happened after i completely got off the throttle and it remained at 0 V for a good 2 seconds while it was idling.

so could my O2 and knock sensors be bad?
 
#6 ·
i removed the lower honeycomb
Click to expand...
Put it back in:rolleyes: Thats your part thottle knock problem and why your leaning out so bad. Your lifter tick will do a # on your timing as well. You could add a can of Engine Restore to the crankcase and see if it makes a diff in knock values without lifter tick.
 
Discussion starter · #8 ·
i thought a lot of people removed the lower honeycombs and were fine? oh well, i will try to get up with the guy who had the car before me and see if he'll send me the honeycomb. i just talked to him and he said he just replaced the O2 sensor and it only had like 100 miles on it when i bought the car.


if the lifter tick is screwing up my knock count, then why am i getting no knock at idle? and a lot of times i am getting 0 knock at WOT. this is confusing.
 
#9 ·
SM00TH976 said:
i thought a lot of people removed the lower honeycombs and were fine? oh well, i will try to get up with the guy who had the car before me and see if he'll send me the honeycomb. i just talked to him and he said he just replaced the O2 sensor and it only had like 100 miles on it when i bought the car.


if the lifter tick is screwing up my knock count, then why am i getting no knock at idle? and a lot of times i am getting 0 knock at WOT. this is confusing.
Click to expand...
i had the same symptoms. one run i could get zero knock from 1st gear through the top of 3rd. the very next run i would get between 20 and 43 counts of knock all through the run. it was very inconsistent. i replaced the knock sensor and it all went away :)

just a side note, my car ran like absolute CRAP with the lower honeycomb removed. put it back in ;)
 
Discussion starter · #10 ·
yeah actually my car idles like shit. it still pulls good and seems to run fine if i'm not idleing. oh well, how much is a new knock sensor anyway? and is there anyway to know if you need a new one short of replacing it?
 
#11 ·
SM00TH976 said:
yeah actually my car idles like shit. it still pulls good and seems to run fine if i'm not idleing. oh well, how much is a new knock sensor anyway? and is there anyway to know if you need a new one short of replacing it?
Click to expand...
i had all sorts of issues with the car occasionally stalling and idling badly... tried fixing EVERYTHING. put the honeycomb back in and it was smooth as silk :)

you could pull the old sensor out and visually inspect it. just look at the back where the wire goes into the sensor. mine was all gooey and the plastic was sorta melted like... hard to explain. you'll know if it isn't right ;) they are like 80 bucks, maybe less. check conecelli they usually have good prices.

word of warnig though, it's a bastard to get to it! it is in the center of the block, under the intake manifold, about 3 or 4 inches below where the runners connect to the head. good luck!
 
Discussion starter · #12 ·
yeah i just checked conicelli and they had it listed at $60 and change. i guess i gotta buy one. i have heard it's a lot easier to get at if you remove the downpipe. since i am getting a custom exhaust made somethime soon i guess i will ask them to put it on there when they have the exhaust off.
 
#16 ·
the lower honeycomb has nothing to do with knock sums. there is not enough of a variance between the o2 trims with it in there or out of there.

all it is doing is lowering the chance of fuel cut

i have mine removed, and screw backed out. guess what. 02 trims are identical to a stock mass.
 
#18 ·
the lower honeycomb has nothing to do with knock sums. there is not enough of a variance between the o2 trims with it in there or out of there.
Click to expand...
EVERY car is different, if your running a stock fuel system IT WILL lean your mid range out alot, more so when it's cold out.

all it is doing is lowering the chance of fuel cut
Click to expand...
It's delaying fuel cut by adding unmetered air into the engine, thus the ECU will not give you enough fuel during part throttle operation.

i have mine removed, and screw backed out.
guess what. 02 trims are identical to a stock mass
Click to expand...
If that was the case, removing the comb would not be doing you any good. Did you varify this with a wide band 02, or the crappy stock 02 sensor:rolleyes:

The lower honeycomb is removed stock on Galant VR4s, so I can't see it causing too many problems
Click to expand...
The stock fuel maps on a VR4 are not the same;)
 
#19 ·
I just logged my vr4 about a week ago and was getting very similar behavior. WHat I've done so far is to replace the fuel filter (may have been clogged). Then on my MAF I put the screw back in to stock as the previous owner had turned it out to lean things out :rolleyes:

So now I'm not getting knock at part throttle, but on boost I am although things are better. I am going to replace the knock sensor as it may be bad. Also just ordered a walbro 255hp, becuase I'm thinking the stock pump with 180k might be getting tired(and I'll need it for future mods). I also will be moving my battery to my trunk, enabling me to do a easy FP rewire.

I'll let you know how things go. Post if the knock sensor replacement helps you out.
 
1 - 20 of 22 Posts
About this Discussion
21 Replies
13 Participants
Last post:
loreak
DSMTalk Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum
posts
2.3M
members
104K
Since
2000
A forum community dedicated to Mitsubishi Eclipse, Plymouth Laser and Eagle Talon owners and enthusiasts. Come join the discussion about performance, turbos, builds, modifications, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General DSM Tech and Tuning Help! Tech Newbie Questions Forum Body Tech and Appearance Electronics Tech