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tunnig issue speed density

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Old 12-12-2012, 11:38 AM
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Default tunnig issue speed density

hello guys. 99 trans am. im not the tuner of the car but my tuner and i got frustrated yesterday. when we couldnt get the car to run properly. idles good around 850. now regular driving the wide band is every where feel like the car misses and the wide band gose lean for that second. i have no o2s and speed density. fuel psi is right at 55. could this be a missfire from a pulg. i filed out a set of br7s from moving the car around from place to place untuned and these tr6s were doing pertty bad also. before tunning we ran it pretty lean to clean them out but nothing. could a misfire make the wide band read lean. im going to do the plugs on the car today to see what happens. but would like to know if that might be the problem or if i should look somwhere else.

mods on the car is
full bolt on
ported 241s
ms3 cam
victor jr efi

stock 98 injectors 28#
stock pump
Old 12-12-2012, 12:49 PM
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If the car bogs and misses it's running too lean and the wideband goes all over the place because of the misfires.
Tune part throttle using a rich tune and a stock Tr55 to avoid fouling.

Set it to open loop, disable all adders. Using a stock VE table add 10-15% more fuel and start tuning. Tune idle first then part throttle.
In the first session it will fall into place
Old 12-12-2012, 01:08 PM
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Originally Posted by MontecarloDrag
If the car bogs and misses it's running too lean and the wideband goes all over the place because of the misfires.
Tune part throttle using a rich tune and a stock Tr55 to avoid fouling.

Set it to open loop, disable all adders. Using a stock VE table add 10-15% more fuel and start tuning. Tune idle first then part throttle.
In the first session it will fall into place
i was thingking about going back to the tr5's for the tuning and then puting in some tr6 for the nitrous i have the the idle set at 14.x range and ti jumpes from 14.0 to 14.8. part throttle its in the 13.x's and when it misses it sipkes 15.x 16.x

so fouled pulgs can make this happen?
tuner told me it could be spark or injectors the injector are fresh tho.
Old 12-12-2012, 07:23 PM
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Originally Posted by lsxTAlemy
...i have no o2s and speed density...
So, you're running OLSD?? Or just SD?
Old 12-12-2012, 09:32 PM
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do you have a fuel pressure gauge on it when it spikes lean?
Old 12-13-2012, 07:04 AM
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Question What I'm

Originally Posted by robbyredneck
do you have a fuel pressure gauge on it when it spikes lean?
wondering.. Stock pump, stock injs and a full bolt-on heads/cam engine??
Your tuner have a way to log fuel psi?
Old 12-13-2012, 08:35 AM
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spark plugs were the problem. i wen tr5s and it runs alot smother. cyl 1 and 7 were pig rich 3 and 5 leaner and 2 was rich and 4,6,and 8 were lean. so im guessing the lean plugs were the plugs that cleared up and the other didn't clear. motor is running alot smoother and the idle on the wideband is at 13.5 13.7 so its not jumping around like before.
fuel gauge is in the rail psi is 55 it drops a tiny bit when throttle but picks right back up. i know i have to lean out the idle and get it dialed in now the its running alot better tuner cant make it for a couple days. thanks for the help guy looks like the car is going to put down some good numbers
Old 12-13-2012, 08:36 AM
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Originally Posted by salemetro
So, you're running OLSD?? Or just SD?
olsd it is i think. i get confused with open and closed. so i say i have no o2s. lol



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