After the rebuild the car need a new O2 sensor and I was not able to get one right away. I drove the car for maybe 30miles no problems. Car sounded good no idle problems or stumbling just had the cell light on.

I had a chance this weekend to replace the O2 with a brand new aftermarket one possibly Bosch. Now the car stumbles during accelration especially before the car is fully warmed up and very rarely after the is at its operating temp, but the car still idles good. I have already ruled out plugs, wires, and fuel pump because they are all new. I just find it kind of odd that the car stumbles with the O2 connected, but without it drives fine. Also thier is no cell light anymore!

 

Cmon guys basically the car stumbles with the new O2 installed and drives fine without it...could the O2 be bad or has this happened to anybosdy else?

 

The o2 sensor you are using maybe putting the car in closed loop or open loop when it should not etc.

What are the motor specs/ecu etc ?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">The o2 sensor you are using maybe putting the car in closed loop or open loop when it should not etc.

What are the motor specs/ecu etc ?</TD></TR></TABLE>


USDM ITR pistons with a P72 head a mild S2S1 cams, and stock Obd1 ECU. I have a chipped ECU with an ITR program but the car does the same thing with that ECU installed. With the new O2 senor the CELL does go away if it was running in this loop mode wouldnt the CELL still be thier? I also changed the TB to a Spoon TB and maybe the TPS or Map are bad but why would the car still drive fine with the O2 disconnected.

 

If your not throwing any cels, I have a feeling you simply need to have the car tuned.

 

The car does need a tune no doubt about it, but why would it run better with the O2 not connected? I just talked to the person who i bought the O2 from and he said he is willing to replace it for me.

 

Cmon guys...Car still stumbles especially if its cold.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mad Money &raquo;</TD></TR><TR><TD CLASS="quote">Cmon guys...Car still stumbles especially if its cold. </TD></TR></TABLE>

Who's "itr" program are you running on the ecu ?
It sounds like your basemap maybe off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">

Who's "itr" program are you running on the ecu ?
It sounds like your basemap maybe off.</TD></TR></TABLE>

Actually I switched out the ITR ECU for my OBD1 P72 ECU. The problem still exists. Im starting to lean towards the Map or TPS might be trashed and im not receiving a Cell. The TB was changed to Spoon TB during the engine rebuild that already comes with the sensors installed. Also, with the O2 disconnected the car runs in open loop mode and these sensors (MAP,TPS) from what I read are not used.
Has anyone had problems with there TPS or MAP without a CELL?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mad Money &raquo;</TD></TR><TR><TD CLASS="quote">Actually I switched out the ITR ECU for my OBD1 P72 ECU. The problem still exists. Im starting to lean towards the Map or TPS might be trashed and im not receiving a Cell. The TB was changed to Spoon TB during the engine rebuild that already comes with the sensors installed. Also, with the O2 disconnected the car runs in open loop mode and these sensors (MAP,TPS) from what I read are not used.
Has anyone had problems with there TPS or MAP without a CELL?</TD></TR></TABLE>

Your map & tps are working fine.
If I were you I would try using a chipped ecu which does not use o2 feedback to eliminate any other possibilities.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mtber &raquo;</TD></TR><TR><TD CLASS="quote">

Your map & tps are working fine.
If I were you I would try using a chipped ecu which does not use o2 feedback to eliminate any other possibilities.</TD></TR></TABLE> also when the ecu goes into limp mode ( as it does without your o2 hooked up) it runs the car richer... so your basemap could possibly be very lean .... are you local to so cal?

 

nevermind you are in NY

 

i have the same problem.