Little problem with Stalling/"Skipping" on an automatic

[BrooklynMW]

The car: 1987 325i Automatic

Lately I've been having an issue with stalling or "skipping" on my automatic. It only happens at low speeds, usually under 25mph, especially when I'm either in traffic or city streets. Basically anytime I am gently riding the gas pedal, stopping and going.

I'm the farthest thing from a mechanic, but it kind of feels like it's missing 2nd gear. Or when I'm riding 1st gear, almost to the point if shifting into 2nd, and have to slow back down. The car will either stall out completely, or "skip", almost like your heart skipping a beat. (the tach and revs will drop out for a split second, and then shoot up right after). Also, when it skips, the Check Engine light blinks on for a milisecond. (Blink and you'll miss it)

Once I've been driving for a while past 40 mph, the problem goes away. The funny part is, that if I slow back down after driving on the highway, the problem also goes away. This leads me to believe that it could be the alternator. Perhaps it takes a good while for the alt to get enough juice out of the battery.

I should probably mention that I've been having abhard time starting it in the morning. Sometimes it just won't crank. Could this be related?


So, my guesses:
-transmission slipping between 1st & 2nd
or
-alternator

Am I spot on, or way off?

Just please nobody tell me it's the transmission!

[gasgasrider]

The typical transmission problem starts out as a slipping in first gear, which if not tended to will get worse to the point of finally not moving at all. Most of the time it will still move in reverse but if you really cooked the clutch pak it won't go in either direction. If you catch it in time and discount the major pita removing the tranny is [threads in the starter would have made it so much easier] it's not a hard, or expensive fix...
As far as likely problems for you, check [or have checked...] the alternator's output and load testing the battery would be good starting points.

[jlevie]

That sounds like an electrical problem to me. not like a transmission problem. The drop of the tach and CEL could be from an interruption of power to the DME or a loss of timing data. The former could be a flaky main relay, failing fusible link, or just low system voltage from a failing alternator and/or failing battery. The latter could be a failing CPS.

A DIY test for the alternator is to fully charge the battery (overnight on a charger). After charging check the battery voltage a half hour or more after disconnecting the starter. It should read 12.7v and should not drop much if you turn on the headlights. Then with the engine idling see if the system voltage is at least 13.5v. And see if the system voltage rises to about 14v at 2500rpm. Adding electrical load (headlights, HVAC blower) should not cause a significant drop in system voltage.

[dude8383]

I believe that he already addressed this issue by purchasing a new relay!

[sohc12vm20]

I don't think its your trany! sounds more like a spark or fuel issue! imo

[CabbE30]

My car (same as PO cept '91) is doing a little stutter in first gear. Like if i accelerate hard or even just moderately i get a little stutter right before it shifts into 2nd gear. Its probably the transmission? I dont know because it doesnt happen all the time, only 'randomly' it seems, & only in 1st gear. The only reason im wondering is because i just changed my injectors to 17#, and a 153 ecu with a markd chip and it didnt do it til about a week after a changed them. Maybe from me beating on it recently? The trans fluid is full.
time for a swap? i just dont want to do the swap and my trans be fine after all.

The reason im posting here is because the PO has the same symptoms except for my Check engine light doesnt come on & i know its not skipping 2nd gear.

[CabbE30]

ok it died today. max speed is roughly 45mph because it slips so bad in drive even after it "shifts". so retarded!
looking for a 5 speed now...

[buguhrich]

I can sell you a perfectly running auto tranny that I pulled from my car this summer. Let me know if you need one.