need help having big probs at the track autotap logs inside!

[slacker69]

Well i went to the track tonight ET streets mounted skinnys up front no front sway bar the works ready to run a new best on spray i havent sprayed for like 5 months so i was kinda scared,
Well as i shifted into 3rd gear i kinda got alittle pulseing feeling so the next run i autotap it and log it and it shows my O2 readings going from like 890-910 then drematicly dropping to 36 or so as soon as a shift into 3rd thats right i said 36 very frigen lean.

http://crappyday.tripod.com/camaro3.8lnew.atc

thats the config file i used

and here are the two log files i made while using th 100 shot

http://crappyday.tripod.com/100_shot.atl
http://crappyday.tripod.com/100_shot_2.atl

remember right click and hit save as if it doesnt work let me know i will email them to u they are very small files.

From what people are telling me my injectors are locking up or my fuel pump is going bad.so please help me out.

[slacker69]

Well the links for some reason are saving as html files so email me please i will send them or u can try to change the names to what they are suppose to be and try that

[Magnus]

wet or dry shot.

whats your fuel pressure on nitrous.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by slacker69:
Well as i shifted into 3rd gear i kinda got a little pulseing feeling so the next run i autotap it and log it and it shows my O2 readings going from like 890-910 then dramaticly dropping to 36 or so as soon as a shift into 3rd thats right i said 36 very frigen lean.<hr></blockquote>

Mine is doing this now too. You're right, it is probably injectors or fuel pump. You may need a fuel pressure gauge to tell for sure.

On mine, the fuel pressure is dropping from 62psi down to under 50psi on the 2-3 shift, which
1.) Lets the car run lean for a moment.
2.) Causes the fpss to cut the nitrous (the pulsing).
3.) Means I need a higher volume fuel pump. (but I will try a boost-a-pump first...)

If the fuel pressure is ok, then the injectors may be hanging. You can figure the likelihood of this by calculating the duty cycle. Autotap will give you the pulse width in milliseconds. Somewhere there is a table of pulse widths to duty cycle %'s, at various rpms. (I saw one several months ago, but have no idea where...) I may have to build one sometime.

The hard part, for calculating duty cycle, is that a 28 millisecond pulse width may only be a 30% duty cycle at 2000 rpms where things are happening slower, but could be 90% at 6000 rpms where there is very little elapsed time between intake strokes.

At 6000 rpms, the injector would be hitting 50 times per second.

If you logged them, what were your max pulse widths?

[John_D.]

<blockquote>quote:</font><hr>Originally posted by John_D.:
Somewhere there is a table of pulse widths to duty cycle %'s, at various rpms. (I saw one several months ago, but have no idea where...) I may have to build one sometime.
<hr></blockquote>

Here is a shot at it, from just playing with the numbers and thinking it through. 20 milliseconds is .020 seconds. At any rpm, a cylinder is firing half as many times as the rpms. So at 2000 rpms, a cylinder is firing 1000 times a minute. Divide by 60 to get firing per second.

Formula for the total time an injector is on, during any given second:
Duty cycle time = (Rpms/2)/60 * pulse width ms*.001)

Then divide by 100 to get a percent.

Simplified:
Rpms * pulse width ms * .0012

Shoot for 85% or less.

Table

ms______RPMS_________________________
___2000__3000__4000__4500__5000__5500__6000
5___08%__13%__17%__19%__21%__23%__25%
10__17%__25%__33%__38%__42%__46%__50%
15__25%__38%__50%__56%__63%__69%__75%
20__33%__50%__67%__75%__83%__92%_100%
22__37%__55%__73%__83%__92%_101%_110%
24__40%__60%__80%__90%_100%_110%_120%
26__43%__65%__87%__98%_108%_119%_130%
28__47%__70%__93%_105%_117%_128%_140%
30__50%__75%_100%_113%_125%_138%_150%

[ October 31, 2002: Message edited by: John_D. ]</p>

[slacker69]

i am gonna hook my fuel pressure gauge and watch it. But my injector pulse is still around 19-20 at WOT even when im runnin lean. It is lean all the way through third my 2-3 shift is really sluggish. then is kinda pulses as the car runs lean and i get quite a bit of knock around 3-4 degress and that is with 4% rich and 4 degrees retardtiming.

It is a Wet kit NX kit

My injector pulse is around 19-20 at lik 5500-5800

[ October 31, 2002: Message edited by: slacker69 ]</p>

[slacker69]

From that chart it looks like im at 92-100% so i take that this is not good and any suggestions like maybe get 24lbs injectors and tune with maft+ and get a walbro intake fuel pump 255

[Magnus]

You need to see fuel pressure...

Perhaps fuel is getting on yoru MAF sensor?

[slacker69]

i doubt it i never had a problem before same tb and tap into the same place. So i think my injectors are lockin up. I think i will just buy some 24 lbs injectors and a walbro intank pump how hard are those to install is there an install guide on how to remove injectors. and how to install a intank fuel pump

[Magnus]

Why would your injectors be locking up? You have a wet kit and your fuel pressure isn't being boosted.

If they locked up your car would either grenade on nitrous or backfire like crazy and die.

[slacker69]

twice just driving around the car will get really sluggish like i lost 100 hp and then when i pop the hood the headers are glowing bright red from heat makeing me think the ijectors are locking up cause i clean my injectors every 4000 miles or so.

[Magnus]

if your injectors lock up you will make ZERO power as you will have zero fuel.

Ditch the MAF T+ for a while, perhaps your settings are a little wrong..

Perhaps your MAF sensor is dirty.

What do your plugs look like?

[slacker69]

my plugs are brand new tr6's just installed them yesterday i was running perfect for a couple of weeks with 4% lean and 4 degrees timing advanced this is NA now my car cant use those setting if i set them to that i get anywhere from 3-5 degrees of KR so something is going wrong with the car.

[John_D.]

Red converter would mean you're running rich.

Red headers mean you're running lean.
Additional kr coming in now also indicates lean.

Magnus is right on the injectors. I wasn't even thinking about you running a wet kit vs. a dry kit.

You need to know the fuel pressure at the time you go lean or misfire. Then go from there.

[slacker69]

ok guys i appreciate the help i will hook up a fuel psi gauge today or tommarow and go see if i can get it to do it again. thanks ill let yall know also where coud i buy injectors i am thinking about a supercharger and heads and cam and at that point i will need bigger injectors