90 Lumina 3.1 Eurosport- Stalls when braking @ redlight/stopsign

[Bluntz|]

This car has sat awhile, but now it is almost running great *minus a few
issues..
First let me say i have ran new gas thru it, some reg and mo*st premium
in the last few days since i got it running again.. I will t*ry to
detail as much as i can on the problems, i am a DIY mechanic* and love
challenges but this issue is kind of defeating me and i need* some
outside input..
It has new Plugs & Wires, coil pack,crankshaftsensor,air fil*ter, oil
filter, oil change, thermostat, battery,and muffler.
The Coil pack was bad, before i replaced it the car made som*e huge back
fires (at least 5) hence the new muffler.
The motor sounds strong now, i have driven it a 100 or so mi*le but here
is the deal, when i come to a stop it stalls. Not so much at* first but
after 10 minutes or half hour it wants to stall when braking* and
stopping. The motor will restart immediately and most times *i can
continue on but sometimes when it is restarted it run 10 tim*es as bad,
for instance it feels like it is out of time perhaps, spitti*ng and
sputtering hard just to get to 25mph.
I have no "Check engine light"... I am at the end of my rope* and
looking for suggestions.
I inspected all vacuum lines and checked for suspicious cracks or anything found nuttin, i disconnected battery and did the relearn idle process and 20 minutes later it still stalled in drive at a stop. Since then the only thing i have done is put seafoam in it. Any help is appreciated.

[jeffcoslacker]

Use an ohmeter to check for a smooth signal rise/drop as you sweep the throttle open and closed. If you get any dropouts, the TPS is bad. EGR or IAC may be sticking, but it should run strong under heavy throttle if that were the cause, so I doubt it.

[jeffcoslacker]

Wonder if your backfiring might have fragged the O2 sensor(s)?

[jeffcoslacker]

Raw fuel contamination (i.e. from bad coil pack) will ruin O2 sensors pretty quick.

[Bluntz|]

if it were the o2 sensor wouldnt the check engine light stay on?

[jeffcoslacker]

Generally, but not always. Depends on what went wrong. If the signal is out of range or missing, yes. If it were in acceptable range but not reacting, no.

[fortier]

I had this happen to mine and went throught everthing and won't get into all that but in the end what fixed it was the cheapest a new computer for $150 bucks hope this helps.

[Bamaboy1831]

Do you smell gas around the engine?

[kip123]

well this sounds strange but a buddy of mine had the same problem it was the torque convertor lock up switch in his tranny it wouldn't unlock when he came to a stop and would stall the engine... for now pull the plug on the switch and see if that works.

www.calgarystreetrides.ca

[KenInKenmore]

oh my god people, I had that same problem and it was just an o2 sensor, but get an OBD1 scanner and read the code that its throwing up. The car will tell you whats wrong. unless of course the computer is messed up...