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need help plz

taman86

taman86

New member
I tried posting this question on the chat but my pc decided to sh!t on me and my phone net isn't fast enough so here I am and it has to do with pcm and kinda tuning. I got my auto tap in a few days ago and I've done three logs, three seperate days, all the same weather and same driving conditions at the same time of day. The car is a 97 gtp with mods in my 1600 E. Hwy. 70 Spc. 63
Taman86.

I've been having driveability issues for over a month now. I got a p0102 dtc fixed but it still drives like garbage. When in open loop it drives, accelerates, shifts fine with no problems but as soon as it switches to closed loop after warm up I can literally feel it switch. Ide be cruising at 38 at around 1600 rpms then when it switches the rpms drops to about 1300 and it sounds like it has no res on. The logged data that I did notice is the commanded afr is 14.7, the O2's are jumping from 8xx to 7x back and forth like that and I'm getting up to 2.x of kr when shifting. When in closed loop and I take my foot of the throttle the rpms hang for a second before dropping to about a 1000, then when I put my foot back on the throttle just cruising to maintain speed at say 40 the rpms will go up to about 1800 then drop back down to about 1400 and the exhaust sounds loud again. When I try and give more then 40 percent throttle it starts to knock and sputter but won't down shift. Does any one have any insight as to where I should start looking?
 


what do you have for a tune?

That T-stat is kinda cold for anything but hot lapping.

The O2's should be going from around 100 to 900 mV very quickly.
 
The tune is stock for now matt. And ya it bounces like that quickly and I'm using autotap to do my logging. As for the tsat, like I said stock tune so the fans don't kick on till 210 or something like that. So the o2s are supposed to bounce back and forth like that then? The wierd thing is that I don't have a cat on my car but it doesn't throw a code for running rich. Also could I be having this problem cuz I removed the egr and havnt had it tuned yet?
 
i'd guess it's your MAF tables being way off because of the ported TB and no tune, have you tried to disconnect the MAF and see if it gets any better?

anyway, i'm betting on MAF related issue, since it works fine in open loop.
 


What if I throw in the factor that I put the stock tb on and reset the computer and it still ran the same even with the screen in? Maf tables still?
 
It does change things. i would still recommend disconnecting the MAF and see if it changes or not. It will help narrow things down.
 
k will do. so today i put this box thingy on which skews the signal for the IAT sensor and tricks the computer into thinking that the incoming air is colder then what it actually is. no i didnt buy it, it was on that car when i bought it but i took it. so i put back on just to see if it still sputters and what not when more then 40% throttle is applied since "colder" air means more fuel delivered. well it doesnt, it actually pulls when boost is applied instead of acting like it is going to die. but i did some real time monitoring and i am getting 14* of kr while cruising at 1500 rpms at 50 and when the rpms are low and i give it gas i think it went all the way to 17* before down shifting but it still had 8 or 9* of kr when accelerating which make me nervous.

so more fuel being delivered runs better, but i am getting a **** load of kr on basically a stock intake system aside from ported tb, and hai, stock sc, stock pulley with headers and no cat. WTF? stock plug wires, AL606's gapped to .055.

i think my next step is to test the fuel pressure to see if maybe my pump is garbage which it is only maybe a yr and a half old. is there a way to test the FPR? i dont even know anymore
 
I'm looking at the stock 97 gtp bin, it does pull timming past 50*C of IAT. Starts at -1 and climbs up to -3 at 80*C.

What is your commanded AFR and timing in PE or WOT? and what do your LTFT and STFTs look like during cruise and PE?

Just another piece of info here, PE is also set to start at 40% TPS in the stock bin.
 
The pe starting at 40 percent makes sense it seems like before I put this box on that at around 40 percent throttle it started it spit and sputter and wanted to die almost. It seems if the pe tables are messed up or something
 


Ya no that isn't happening AT ALL. I recorded a video log on my phone but can't get it to upload to youtube. My stft for sensor 2 is locked at 99.2 percent because of having no cat I assume but the milivolts are jumping around a lot on that sensor. Wierd thing is that my autotap info says that "the scan tool will report 99.22% if the associated sensor is not used in the short term fuel trim calculation."
 
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Ltft bank 1
Stft from bank 1 sensor 1
Stft from bank 1 sensor 2

Well for a quick wot burst snap shot my afr dropped to 11.4, -8.0 timing, 3.5 kr, -9.4 ltft, 0.0 stft. That was a quick dip of the throttle in first gear. I can't post up a log until I get my lap top back from a friend cuz it died.
 
Here is a video of a log I recorded on my phone uploaded. At this point of the log it is 35 to 55 mph transitions speeds and cruising till it levels off which is where I stopped and turned into my driveway. At the point of the log where the kr is at 7* then dropps off is when it shifted to 4th and about 45 to 50. I was giving it more throttle and the more throttle I gave it the more kr and thee rpms would drop below a thousand before I would let off the gas and the rpms would come up.

YouTube - Gtp data log
 


Well it seems as if my pe tables are messed up or even just my fueling in general. Even when I switched the old throttle body out with no effect and reset the computer. About a week after I switched the tb's out is when my car started running like garbage and my mpg's went from 23 to about 15 or 16. Would it be linked to the cat being removed and the o2 still being in place?
 
02 MV jumping around is normal. You have knock because the cars pulling 9.4 of fuel in PE. -9.4LFT WOT. You need a maf tune. Oh and commanded AFR means dick WOT
 
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