Help!!! Driving it off a cliff

:banghead: For the last month my 93 Lumina 3.1 has been nothing but a headache. Everytime I think I have it figured out something else goes.

First off my code reader is reading 12, any one got a better explanation than systme good, cause obviously it is not!

Symptoms: Drives good for a while and then stalls at a light, when I am coasting it still feels as though I am pressing the gas.

Repairs to date:
New spark plugs and wires, fuel systme service (injector cleaning, flush, change fuel filter), transmission flush with seals and gasket changed (was shifting poorly, not anymore), cleaned throttle body, oil change, air filter changed, new map sensor, electrical testing, new pcv valve

Mechanics suggested cleaning throttle plates, could this be the cause or is it something more sinister?

Any suggestions would be helpful....I am running out of patience and money!!
Mechanics couldn't find nothing and suggested a full tune up which included everything that I have mentioned (most I did myself). I can't afford their trial and error much longer:crying: PlEASE SHARE YOUR WISDOM....IT IS GREATLY APPRECIATED

[quote=grgluvscars]:banghead: For the last month my 93 Lumina 3.1 has been nothing but a headache. Everytime I think I have it figured out something else goes.

First off my code reader is reading 12, any one got a better explanation than systme good, cause obviously it is not!

Symptoms: Drives good for a while and then stalls at a light, when I am coasting it still feels as though I am pressing the gas.

well, code 12 means no codes have been set, not much more you can say about that. I am just wondering since you say it seems like "coasting it still feels as though I am pressing the gas." If it isnt your transmission TCC switch possibly not unlocking? would also explain stalling when stopping, depends on what it does when it stalls, if it cuts off clean, bucks, jumps and then stalls, or if it feels like it still trys to pull and you are using the brakes to stop it, sorta like trying to stop a manual transmission car without depressing the clutch?
High rpms with throttle less than that rpm, could also be a vac. leak in a hose around the engine too. Ever check the PCV valve and hose under the intake top plenum? Just putting idea's to ya.

:banghead: For the last month my 93 Lumina 3.1 has been nothing but a headache. Everytime I think I have it figured out something else goes.

First off my code reader is reading 12, any one got a better explanation than systme good, cause obviously it is not!

Symptoms: Drives good for a while and then stalls at a light, when I am coasting it still feels as though I am pressing the gas.

Repairs to date:
New spark plugs and wires, fuel systme service (injector cleaning, flush, change fuel filter), transmission flush with seals and gasket changed (was shifting poorly, not anymore), cleaned throttle body, oil change, air filter changed, new map sensor, electrical testing, new pcv valve

Mechanics suggested cleaning throttle plates, could this be the cause or is it something more sinister?

Any suggestions would be helpful....I am running out of patience and money!!
Mechanics couldn't find nothing and suggested a full tune up which included everything that I have mentioned (most I did myself). I can't afford their trial and error much longer:crying: PlEASE SHARE YOUR WISDOM....IT IS GREATLY APPRECIATED




because of the age all vacuum hoses must be inspected and if cracked/collaped etc replaced , also any pcv hoses removed and checked for blockage in other words is there a lot of vacuum at pcv, if this is plugged will cause this, this is step 1. step2 measure fuel pressure and if you drive around with less than 1/4 tank and replace fuel filter like never , it is probably cooked.

I'm liking the TCC here also....if it feels like it fights to stay running as you stop.

If you have original mileage in the 75-100K range, it's even more likely.

I'm liking the TCC here also....if it feels like it fights to stay running as you stop.

If you have original mileage in the 75-100K range, it's even more likely.



if the tcc is bad this causes immediate stall when shift selecter is placed in drive. usually acts up after warm up. most of these problems were in the 80's. the feeling of not wanting to slow down when coming to stop could be the engine controls trying to increase idle to prevent stall. so if it stalls in neutral tcc is out, as the cause.........however the transmission flushing i do not agree as a proper way to remove/replace transmission fluid. if they droppped pan cleaned pan installed new filter then used the inline transmission fluid replacement proceedure as described in the repair manual this is ok. i would say that your transmission will have problems shortly if not done as i described........

Incidentally, a "12" does NOT mean all is O.K., and does NOT indicate a diagnostic mode. Many people don't understand that is can be an actual error code - Distributor Reference Pulses Missing. That can occur during a drive cycle, and lock the code. If there are no other error codes, that's an item to check.

Of course, ad "12" will always appear during a scan, since the ignition is on and engine is off (no reference pulses). If you connect a REAL scanner (bidirectional) and perform a drive cycle, you could see a "12" set while driving if the ignition primary had a problem. Try it sometime.

Thank you all ..............I took the throttle body off to clean the plates and discovered a mess of sorts. Parts were disconnected with in the throttle body, other parts around the throttle body were improperly connected, a gasket was missing.....I am now searching for the gasket to replace so I can put the throttle body back on (fully put together), connect everything properly and then if the problem persisits will check the tcc.... Again thank you all