1993 Grand AM Stalling and poor acceleration

[Jac_ga]

1993 Pontiac Grand Am
2.3 L SOHC Quad 4, Automatic Trans (3sp), 154,000 miles

May 2003 - Started acting up, after about 10 miles, the engine will lug (acts like it is shifting to high gear). Stalls at stop.

Symptoms:
„h After driving about 10 miles and the engine/trans is warmed up, the engine will stall when car is stopped and bogs down (missing?) when accelerating.
„h Accelerates better when manually shifted from 1st, 2nd, Drive (keeping engine revs high). During acceleration in drive, seems to be upshifting too early.
„h Starts and runs fine after stalling, but stalls after shifting to reverse or drive.
„h When in park/neutral, if a heavy electrical load is added (headlights, A/C, or blower) the oil pressure light will flicker (engine momentarily slows). May not be related.
„h Steadily getting worse over last several months.
„h Update (7-6-03): Drove car 30 miles with no problem - outside Temperature was 75 degrees (much cooler than previous problem times) - appears Temp related
„h No check engine light.
„h Runs fine when cold.
„h Other than normal maintenance (plugs, O2 sensor, etc) and replacing head gasket @ 146,000 miles, the engine and transmission are original.

Actions taken:

„h Checked all vacuum lines and electrical connections - no problems.
„h Disconnected TCC (torque converter clutch) solenoid - no improvement.
„h Changed A/T filter and fluid, flushed 10 qts of fluid from A/T cooler connection- no improvement. Note-no debris in A/T pan, normal small amount of gray powder on magnet.
„h Added Lucas "transmission fix" to A/T 154,030 mi on 5 July.- no improvement.
„h New fuel filter - no improvement
„h Checked ignition coils and spark plug boots. No visual problems. Coil resistance on both is 0.6 ohms. Coil to spark plug boot resistance is 0.7 ohms. No shorts to ground. Readings taken with components cold.
„h Disconnected MAP sensor when started acting up ¡V no improvement


Initially, I thought there was a problem with the automatic transmission. Now, I'm not sure. I'm thinking it may be a fuel or ignition problem.

Any ideas? Thanks

[Flatrater]

Check fuel pressure and volume also check exhaust back pressure!

[jzarkadas]

I had the same problems with my 93 grand am with the 3.3 V6. I first had the TCC solenoid changed which stopped the abrupt stalling(I don't know if you had the same stalling problem as I did. On my car it would start after about 20 minutes of driving and would sound like almost like grinding when it would stall. After 30 minutes it would be fine to drive again). My driving performance then started to degrade. Then I had the Mass Airflow Sensor (which is mounted between the air intake and the air filter) replaced. It was a 200.00 part, but the minute I swapped it out my performance problems dissappeared. I hope this helps.