I own a 93 coupe DX and i had just recently put another LS motor in it.First, when i start it in the morning, it doesnt idle.Second, even when its warm it has a skip until 1500-2000RPM, and the last thing is when im in the lower R's, like below 4000, and i floor it, it goes slower than 3/4 throttle.the only code im throwing is my o2.Any suggestions?

Derek

 

What exactly do you mean the car doesnt idle? Does it jump or what?

Also yea a bad o2 sensor could be the cause of everything because it judges a/f and such. Also if theres a code for o2 i think you go into limp mode, but dont quote me on that.

 

1st why dont you take care of the o2. what do you mean by it doesnt idle? does it fluctuate? what kind of skip do you get? a skip/misfire is usually related to the ignition system, when were the plugs/dist cap/rotor replaced? when was it inspected? how does it look? take off the intake and look at the butterfly at WOT, is it fully open? your using an ls motor, the cable might not be adjusted. you have to check these things and then post again.

it could be so many diffrent things, tps, o2, insufficient spark, tune-up...

 

heres the deal.I had just swithched dist., changed plugs wires cap and rotor.My TPS is new and my throttle is the correct cable and goes WO.I had just wired the O2 today, it is wired correctly and i still have a code 41, O2 heater.I had traced the wires to the junn. conn. and to the ECU.it is a brnad new 02.They all have no breaks in them.The idle probleme is only in the morningor when, it doesnt idle, u have to stay on the gas, but when u get to operating temp, it will idle at 1100-1300, and after a hard day driving it idles at 1300-1500 and has even gone upto 2000.I have a feeling to IAC isnt working but that shouldnt make it not idle at all.The skip is always there,it doesnt matter if it is upto temp or not. but smoothes out in the higher RPM's.The ECU is always in open loop and i am loading up with fuel, my pressure reg is working and hooked up correctly.The motor is bone stock.WTF?????

 

is your TPS calibrated?

 

My TPS is at 14% at closed throttle but only opens to 93% at WOT.The butterfly opens fully also.I had just changed my ECU today and noticed the skip was gone and my check engine is off.The previous ECU was evidently a 92-93 teg and my courent is a 94Ls.


Modified by 93supercoupe at 4:09 AM 6/3/2004

 

your TPS should be at 5. volts closed and 4.5 volts at WOT.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93supercoupe &raquo;</TD></TR><TR><TD CLASS="quote">My TPS is at 14% at closed throttle but only opens to 93% at WOT.The butterfly opens fully also.I had just changed my ECU today and noticed the skip was gone and my check engine is off.The previous ECU was evidently a 92-93 teg and my courent is a 94Ls.


Modified by 93supercoupe at 4:09 AM 6/3/2004</TD></TR></TABLE>


did these problems go away after the ECU change?

 

when i diud the ECU change, the car runs great but still, when i floor it it slows down, it boggles my mind lol.

 

thats messed up

 

It could be the O2 sensor. My Jeep ZJ had a bad O2 sensor and on top of that, a clogged catalytic converter. So, my Jeep ran like completel TRASH for a week or so and gas mileage went down drastically. Changed catalytic converter and O2 sensor, everything went back up and car runs like new again, or even better.

 

it's slower cuz it's bogging out due to an overly rich condition, the same condition that took out your O2

above 70% open throttle, the ECU goes straight to lookup tables with no feedback loop. Something that feeds the ECU the open loop info is fuct.

 

check your fuses.

I had a blown alternator fuse and it was causing the CEL to come on and when i pulled the codes, it was throwing both O2 sensors and ELD (electronic load detector)
i changed myprimary O2 anyways becuase it was fried..

 

subscribing to thread

 

so i did more tuning today, lol, my timing was way off. fixed that.Heres the deal now, i have no sputter but it still doesnt idle when cold.When upto temp, the idle is sparatic, sometimes it idles great and others it acts like a vacuum leak and others it just stays real high or real low.Another thing that had just occured w/ the ecu change was mass power surging.The only thing i could think of is that i am running OBD-1 GSR injectors, but i cant see that being a probleme since my car is OBD1 also.Ill go change my injectors w/ LS OBD-1 and check for vacuum leaks but im positive i dont hgave any.I cant boost if i cant get this thing running good NA.Also, my check eng. is off and the O2 is new.