3800 KR caused by bad O2 sensor?

[98 TGP TOY]

So my friend has been itching to race me laterly (Z28). So I took him up on the offer. I got rid of my bypass mod to knock up my boost a lil in hope of a good race. Well we went out, first race he got me around 80-90ish. Second race I took him the whole way. So I took logs while racing to see if how things were looking. And I got one lil blip of .26 degrees. Thats it. WTF??.

Well now the problem. Only mods since my last similar run was dhp and mini afc. And it dropped me 6 degrees of kr and upped me to 21 degrees of timing. So I looked at my logs my IPW are absurd, 5624 rpm with IPW of 21.49. So it looks like my injectors are going static, if not really close. And my O2s are at 980s for most of the run. This is with my afc 1.1 at 98%.

So my thought is this. My O2s are reading richer than me exhaust actually is. So my injectors are putting out more than they need to, causing me to be static. So I think my O2s are a lot closer to a reasonable tuning number, but wont read it. But I still have 0 KR...WTF? Im confused. All mighty tuning gods help me....thanx.

Here is the log

Click to read more...

 

[98 TGP TOY]

Also, I have noticed that when my injectors get closer to going static, I have less KR. When my IPW is far from static, I get absurd KR. Just another tid bit.

 

[xttc2000]

your injectors are still good at 21.49

o2s generally dont read wrong, theyll work- or they wont.

with 02s as rich as you are, i would look into a fuel problem- check your fuel pressure and test your injectors. also plugs- what plugs and gap are you running?

rich is safe, lean makes power. if you can lean it out without getting knock youll be making boatloads more power.

 

[98 TGP TOY]

Well the KR document at the top of this section says they are borderline static. So thats what I was going off of. I am running autolite 104s with a .56 (I think) gap. I can check the fuel pressure in two weeks, but not any earlier. Getting busy around here.

 

[98 TGP TOY]

OK, Im thinking this has to be a fuel issue. I just put my CAI back on today, because I have been messing in the engine so much, i put a HAI on for a lil. Then I went out and did a run. I saw a max of 2.XX degrees of knock. And my IPWs were back down again, peaking at 18.81. Also, my O2s averaged 940.

So everytime that my IPW's drop and my O2's drop, I am getting more KR. And from my understanding 940 is still rich. So where do I start? Should I swap the some spare injectors, with 40,000 miles, into my car. They were sprayed with a lil brake cleaner though, will that damage them? Any suggestions?

 

[rob]

Originally posted by 98 gtp toy@Apr 29 2004, 04:07 AM
Also, I have noticed that when my injectors get closer to going static, I have less KR. When my IPW is far from static, I get absurd KR. Just another tid bit.

Try leaning it out a little more to see what happens. I beleive a little rich condition can cause KR aswell due to the possability that there is some residual unburnt fuel igniting on the compression stroke.

DHP may have altered your fuel tables some + and raised your timming. So it may be a matter of tuning your mixture to your combo.

Dont think that you have a 02 problem. Brake clean wont hurt your injectors. Its almost the same thing as carb cleaner.

Is your fuel pressure reg. stock? Im not to kean on the therory of richening the mixture by increasing pressure. But, if its adjustable, try to bring it down and see what happens.

 

[98 TGP TOY]

OK, if I get some time later, I will try leaning it out more. And my fuel pressure regulator is stock. Once summer starts for me, I will probably swap the injectors too, especially if we can get that prj fuel rail buy moving. Thanx for the suggestions.

 

[rob]

I wouldnt sweat the injectors....Yea, theres alot of ways they can fail: electricly or mechanically....But, generally the idle will suffer and a misfire will be present.

Your the guy that set that fuel rail poll. What were the results? Has Paul given you a decent quote.....? Provided we have a couple interested.

Just want to say for the record not to spay anything on 02's.....

 

[98 TGP TOY]

I didnt start that poll. That was CoolGTX. I just wish we could get it moving, because I would like to see what the prices are.