My 1988 325i: Dr. Jekyll and Mr. Hyde

[Sallytenn]

Hello! I have a question about my 1988 325i.

I just bought it about a month ago. The guy who owned it replaced a ton of parts (new battery, new muffler, new catalytic converter, new fuel pump, etc.). Plus, it only has 66K original miles. I tried it out and it drove great. No shaking, no stalling--nothing. Well, I had it parked on a street near my house for a week (I didn't want to drive it until I had a chance to register it). I went to drive it, and it stalled CONSTANTLY. I had to drive the car from Philadelphia to Buffalo (a 6.5 hour drive), and as the title of this thread insinuates, it was either horrible or PERFECT. For the first 15-20 minutes of driving, it would stall out almost constantly whether or not I had my foot on the gas. Then, the stalling stopped, but every so often, it would hesitate a time or two. These hesitations got more and more spaced out until it was driving perfectly. I stayed overnight on my way home, and when I went to drive the car, it was okay at first. Then, it started stalling out on the thruway while I was going 60-70mph. The tachometer would go from about 2-2.5 to 0 suddenly, and even though the lights inside were still on, the engine shut off, as well as the power steering etc. As a side note, it was raining really hard that day.
I was nervous about driving a car that was stalling out while going 70mph in low visibility weather, so I stayed at a hotel over night. The next day was clear, and the car drove 2.5 hours home without a hitch.

I put premium gas in it when I got home (I thought it was bad gas coupled with a lot of junk in the fuel lines already), plus injector fluid. It ran beautifully (no check engine light, no stalling, no hesitations, etc.). No one believed that there was a problem in the first place. I took it to my mechanic to get inspected, and he couldn't find anything wrong with it--he was really impressed with all of the high quality new parts in it, including the fuel filter.

It was great until the other day when I went to work. I drove it 1/2 an hour to work (speeds ranging from 30-60mph) and it was fine. Well, when I drove it next, it started REALLY acting up again like it had before. By the way, this day was really rainy too, although these symptoms have continued on and off for the last 5 days regardless of weather. Here is a list of things that are wrong with it:
1.) Check engine light comes on/goes off/flickers.
2.) Brake fluid light sometimes comes on (brakes work fine and fluid is new).
3.) Engine hesitates ("chugs"), sometimes one time before going on, sometimes many times in a row.
4.) Engine stalls when idling AND when driving. Car DOES start right up again.
5.) Tachometer drops, and I push the gas pedal more--suddenly something kicks in, and the car shoots forward.
6.) Occasionally, the tachometer stays at 1 (or slightly above) while I am braking (instead of being at about .5 like normal), and it is hard to brake because it feels like the engine is still trying to go forward while I am trying to brake.

Some problems that it DOESN'T have:
1.) The engine is always cool--it hasn't come close to overheating.
2.) When it stalls, the interior light stay on--only the engine kicks out. Also, as I said before, it always starts right back up.
3.) No weird smells, smoke, sounds coming from anywhere.

As you might have figured out, I don't know much about cars. I need to take it into the shop (I think), but I would like to see what people here think. Thank you for your help, and I hope to get this problem solved soon!

[grafhky52]

go to the dealer and let them read the fault memory. and go from there

[royemello]

i agree with last post , go to a dealer- or a real BMW repair shop & ck fault codes.
i have older 325's, at 66k this car sat a long time, corrosion, dirty contacts, old wiring, cold solder joints etc. all could be involved. might have multi sm problems that act up. do yourself a favor go from head lights to tail lights & ck everything - AFTER A QUALIFIED BMW REPAIRMAN- ERR PERSON !clean & ck ALL batt terminals & grounds - both ends- once you find the fault / faults re'ck everything again. inspect - clean & lube (dielectric grease) everything !
do it real good ,re'ck /re'ck/re'ck. even the elec connections @ the fuel pump, expecally if you have a external pump. just go thru it !, by then you'll know your bimmer in your sleep. then they will run forever (reg maintenance required)
good luck

[88325i300K]

Check the connection under the car to the o2 sensor i spent 6mo's and hundred's of dollars trying to correct the same problem then one day i noticed the o2 wiring just hanging, not connected to the sensor (the sensor hole was plugged?)i disconnected the coupling under the hood Its orange or yellow, be careful though a similar plug is used for the airbag i think, near the pass side shock tower. my car always stalled in the rain and snow until i did that, i think the water was somehow messing up the signal to the CPU? Good luck

[coolbear1]

It could ba a bad ECM. Sounds like too many things are going on. Most sensor inputs will send it into a limp home mode, not a total shut down. Maybe dirty harnes plug, or ECM input plug.
Could also be crankshaft possition sensor. Or in your case I think it is a pulse sensor.