Found my knock issue

[the baPhoon]

After installing my PLX WB i found my knock issue under wot.
My ratio at idle is around 10. WOT itll dip down to around 7-8ish. Loads of knock.

Damn this truck is running rich. Anyone else have this problem?
Truck is mostly stock. Stock injectors, no AFPR, 3 inch catback.
When i ran the wires to the ECM i found the stock do not remove stickers still on the ECM over the Eprom so i know theres no chip messing with the fuel tables.


The hunt continues haha.

 

[NecroWolf]

Re: Found my knock issue

stuck injector or two?

 

[the baPhoon]

Re: Found my knock issue

Possiblility.
May run some injector cleaner through and see what happens.

 

[WyoSyclone]

Re: Found my knock issue

When i ran the wires to the ECM i found the stock do not remove stickers still on the ECM over the Eprom so i know theres no chip messing with the fuel tables.

I thought that about mine too, but found someone had cleverly taken apart the ECM case and stuck a KB chip in it, without taking the label off. Might be worth a check.

 

[NecroWolf]

Re: Found my knock issue

i found my stuck injector by pulling the plugs and finding the wet one

 

[the baPhoon]

Re: Found my knock issue

Ill go ahead and do all of the above. My KR is killing me. Knocks ALOT.
Im gona take apart the ECM also and check for a kaboom chip.

Just got back from autozone and lowes. Put in a tube of that cheveron injector cleaner just to be on the safe side. Almost got 2 galons of Xylene but i wanna get down to the issue before i start questioning fuels octane rating. God im not excited about pulling these plugs hahaha.
The cruise was about 15 miles, WOT and cruise all with the same result. WOT from a stop AFR would drop to 7.5 8ish. Light throttle 8-9ish. cruise fluxuates from 9.5 to 10.5.

What would a stockish truck run? I've read it before i would just like to not seccond guess myself haha.

 

[leroy]

Re: Found my knock issue

If you are that rich, you should have a check engine light with a code 45. I would question the accuracy of the PLX, if you don't have the code.

Jim

 

[silverblaz]

Re: Found my knock issue

seems like your truck is running in LIMP mode my truck did that when i first got it running ended up being a power problem to the ECM

 

[sly dvl]

Re: Found my knock issue

Ok, I'm confused. Why would a rich running condition on a primarily stock truck cause knock?
Enlighten me please...

 

[WyoSyclone]

Re: Found my knock issue

Ok, I'm confused. Why would a rich running condition on a primarily stock truck cause knock?
Enlighten me please...

In all of the Code59 tuning I've been doing, anything richer than 10.2 in my Sy causes knock - probably too much fuel wiping out the spark. I don't know if one of our motors would even run down in the 7 range... I can't remember, does the PLX gauge even go down that far?? I thought it just displayed 'rich' after a certain point.

You didn't happen to finger the element on the O2 sensor when you were putting it in did you?? Not supposed to touch them with you fingers.

 

[Flyin Ryan]

Re: Found my knock issue

Is it as rich during idle or is it just under WOT?

ideas that come to mind are:

o2 sensor
faulty fpr
leaky injector
MAP sensor (unplug it and see if that helps or swap in a different MAP)
TPS (false indication of the engine accelerating)
EGR (EGR staying open causing O2 sensor to indicate a rich exhaust but normally results in a code 45)


First thing i'd do is check out what chip you have installed, check the fuel pressure regulator by seeing if the vacuum line to it has fuel in it then go from there

 

[Andreas]

Re: Found my knock issue

MAP sensor (unplug it and see if that helps or swap in a different MAP)

Some years ago I had my truck running so rich it stalled all the time, changed the MAP sensor and truck run great

 

[TYTILIDIE]

Re: Found my knock issue

What you really need to do is post up a Datamaster run. WB can only tell you your are rich but a good DM file MIGHT point you to what it is. FPR on stock truck made mine run then rich. $35 later it ran great.

 

[nello]

Re: Found my knock issue

My truck had one cracked injector tip. Caused a drip or stream of fuel instead of an atomized spray. Fixed it before I ever ran DM so I don't know how it would have read it, rich, lean? I do know it ran like poop though before I fixed it.

 

[silverblaz]

Re: Found my knock issue

can you hook up data master? try and see if you can or not if you cant your truck is in Limp mode for one reason or another

 

[the baPhoon]

Re: Found my knock issue

Gona be making a run on DM this evening. I DO throw the EGR code from time to time and i knew that might be an issue but i didnt think it would read as rich as it does.

WOT it will spike to low 7s and then hang around around 8-9ish. Idles between 9.5 and 10.5.

Nah i didnt touch the O2 element while installing.

Occasionally while at a light or just idling the truck will kinda bog down and seem like its gona stall but it never stalls, just a little hicccup and its back up to its regular idle revs. Before my DM latptop took a crap i was running a IAT error, MAP issue and EGR code. I changed all my vac lines and the IAT and MAP issue went away, but present themselves from time to time. Still have the EGR issue, itll pop on if i cruise on the freeway at around 70ish for any longer period of time.

 

[NecroWolf]

Re: Found my knock issue

vacum leak elsewhere? tried the bike tube test?

 

[the baPhoon]

Re: Found my knock issue

theres a possibility. Im gona go back out and replace all the vac lines again tonight and see if that changes something.
The only line i didnt replace is the hard line under the intake on the front side. So im just gona redo the whole damn thing and see if that works haha.

 

[Flyin Ryan]

Re: Found my knock issue

http://www.syty.org/old/d&e-code45.html

 

[the baPhoon]

Re: Found my knock issue

Yeah its gotta be the EGR. Damn thing on my last DM run was 60% open all the time.
Time for a new EGR valve