KR and adding timing??
So got the fuel pressure gauge on the car, readings are as follows:
55psi at idle
30psi when I hit 4000-5000rpm and we didn't bother taking the car higher than that.
fuel filter is completely rusted on, so I am guessing it is original. We will keep soaking it until Monday and should be able to replace it...I am guessing the pump is getting weak?
55psi at idle
30psi when I hit 4000-5000rpm and we didn't bother taking the car higher than that.
fuel filter is completely rusted on, so I am guessing it is original. We will keep soaking it until Monday and should be able to replace it...I am guessing the pump is getting weak?
Teching In
Joined: Sep 2013
Posts: 43
Likes: 0
From: Straya
Good work. I would probably try just the filter first, depending on how expensive and hard to replace the pump is. You should make sure the wiring and connectors to the pump are in good shape too.
You'l definately notice extra power once it's getting the fuel it wants! They do run smoothly with lean mixtures, but you'l be down at least 10% power. I've experimented with cruise mixtures as lean as 17:1 with no noticable missfiring, but the throttle response gets lazy and there's not much economy benifit going that lean.
You'l definately notice extra power once it's getting the fuel it wants! They do run smoothly with lean mixtures, but you'l be down at least 10% power. I've experimented with cruise mixtures as lean as 17:1 with no noticable missfiring, but the throttle response gets lazy and there's not much economy benifit going that lean.
so it was the fuel filter it looks like. I didn't have time to get the gauge back on to verify, but after replacing it and scanning it looks like I no longer go lean on the narrow bands anyways.
Now next problem...why in Gods name is there so much KR in the stock GM tune...
Now next problem...why in Gods name is there so much KR in the stock GM tune...
KR attack rate is too high and decay rate, too slow.
That's how GM keeps every stinkin' Camaro from coming
back in for ping complaints and holed pistons. Overkill.
But for tuning and riving, halve the attack and double
the decay, you'll retain some safety measure but not
be dogged for seconds from some tip-in knock-detect
blip.
When you tighten it up, KR then becomes more usable
as something to tweak timing against. Stock, too much
is obscured in the wake of the KR so you don't know if
it's a transient or a steady state problem (fuel or spark).
That's how GM keeps every stinkin' Camaro from coming
back in for ping complaints and holed pistons. Overkill.
But for tuning and riving, halve the attack and double
the decay, you'll retain some safety measure but not
be dogged for seconds from some tip-in knock-detect
blip.
When you tighten it up, KR then becomes more usable
as something to tweak timing against. Stock, too much
is obscured in the wake of the KR so you don't know if
it's a transient or a steady state problem (fuel or spark).
I only replaced the filter, I never pulled the pump. The pump is fine, when the power level gets to the point I need a racetronix I'll go that route.
KR attack rate is too high and decay rate, too slow.
That's how GM keeps every stinkin' Camaro from coming
back in for ping complaints and holed pistons. Overkill.
But for tuning and riving, halve the attack and double
the decay, you'll retain some safety measure but not
be dogged for seconds from some tip-in knock-detect
blip.
When you tighten it up, KR then becomes more usable
as something to tweak timing against. Stock, too much
is obscured in the wake of the KR so you don't know if
it's a transient or a steady state problem (fuel or spark).
That's how GM keeps every stinkin' Camaro from coming
back in for ping complaints and holed pistons. Overkill.
But for tuning and riving, halve the attack and double
the decay, you'll retain some safety measure but not
be dogged for seconds from some tip-in knock-detect
blip.
When you tighten it up, KR then becomes more usable
as something to tweak timing against. Stock, too much
is obscured in the wake of the KR so you don't know if
it's a transient or a steady state problem (fuel or spark).
I've started dialing back the timing in effected cells and I've halved what I was getting.
Now granted, I have two original spark plugs still stuck in the car, so that could contribute, but this is just brutal...my 6 after I tuned it would get 0.5* here and there (which was great, because I was aware the kr sensors were functioning still)
4-7* while cruising and with tip in is just insanity...I like my cars running with zero kr- the way they should be.
I mean, Im looking at timing on the stock maps in the high 30's...why in the hell does it need to be that high? better combustion?...on a coil per cylinder setup?....
You should really start by tuning the maf table since you have a lid. Any change in the intake tract will affect maf cal. Then once your fueling is correct you can worry about kr if there is any. Before you start make sure the maf is clean and unless you unbolt the screen housing you can't clean it properly.
TECH Addict
Joined: Nov 2005
Posts: 2,379
Likes: 2
Don't touch the timing in your part throttle right now while stock. As flame stated, work on calibrating the maf correctly and seeing if your kr situation is reduced. Afterwards, play with the tables until the kr is a tool for your use and not some overprotective safety net.
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