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-   -   03 325xi starts but dies (http://forum.e46fanatics.com/showthread.php?t=976292)

eeleaj 03-14-2013 11:16 PM

03 325xi starts but dies
So I went to work today car ran fine. After work I go to turn on my car and it started up but died right way. Tried it a couple more times and it just kept dying. Tried pressing the gas pedal while turning the car on and it died. No fault codes. Engine turns on but keeps dying. Cant figure it out. Any help would be appreciated

325xittt 03-15-2013 06:23 AM

Likely dead fuel pump. Could be the relay behind glove box but probably the pump. Our pumps are known to die suddenly and without warning. Remove the rear seat, turn the ignition key to the on position and within the first 10 seconds listen for the pump to prime the system. Located under passenger seat. If no pump noise check for power at the plug with a volt meter or test light. If no power its your relay. If you get power then its your pump. If you hear pump noise then you likely have problems else where. Lots of threads and diy's on this subject

White_Knuckles 03-15-2013 08:11 PM

Yep, fuel pump. After checking the dedicated fuse of course. Change the filter at the same time the pump is replaced.

eeleaj 03-22-2013 10:32 PM

So I cleaned my maf, idle control valve and the car ran fine for a week. Then today after work I go to turn my car on and it died again. I hear the fuel pump priming so im pretty sure its not the fuel pump. Todays experience was alittle different from before. The car turned on and stayed on, idled fine but when I went to stomp the pedal to rev the engine up it died right away after reving to about 1200 from 800 idle. I turned the car back on and it stayed on, stayed idle at 800. I gently pressed the gas pedal and it slowly revs up but when I goes to about 1800 the revs goes up and down from 1800 to 1000. If I gently press the pedal to rev it past 2k and try to keep going up it will drop to 1k and act like its gonna stall, but if I let go of the throttle at that time the car will go back to idle and stay idled. No check engine light but my EML, and traction control lights came on when it died once .Any thoughts.
im thinking the problem might be my throttle positioning sensor (tps) would i need to change my whole throttle body for this?. But I would like some more input before I buy and tear out my intake manifold to get to the throttle body. Please give me your thoughts thanks

eeleaj 03-23-2013 12:43 PM

So I had my brother take me to go to my car because I was gonna have my car towed from my work. I go to turn on my car just to check if itll start so I can save myself the cost of towing if it started. My car turned on without any problems, idled fine, revved up normally, and it drove fine back home which is about 7-10 miles away. I brought it home and left the car on for about 30 minutes sitting behind the wheel revving the engine up and down randomly to 3k, 4k, 5k , 6k then repeated the cycle over again. Every time it would rev up fine and idle fine when I let go of the pedal. I opened the hood and nudges any visible hoses and wires to see if there might be a leak or bad connection and nothing happened. Please help me try to figure out what this problem might be. Im scared to drive my car anywhere because it might suddenly not stay on or I wont be able to drive it home. Any help would be greatly appreciated

White_Knuckles 03-23-2013 12:49 PM

This is a tough one. There are several variables to what might be the culprit. The fact you can hear the pump spin up is good but you can't tell what the pressure is at the fuel rail. A failing pump or restricted filter will duplicate that symptom as well a sensor, etc. I fought a failing intake cam sensor that had symptoms that were similar with stalling. My car would intermittently die with never a code to be thrown. I got lucky and a new sensor cured the evil. That does not suggest it's your issue just pointing out how mysterious chasing these problems can be.

You need to isolate the problem and solve for what's happening before throwing parts at it. Is the car starved for fuel when this occurs? Is the DME going crazy with inputs like the TPS drifting? The only way to tell is getting a diagnostic monitor on the thing. There is a very reasonable software logger out there that does this well. It costs around $50 and you'll need a $10 USB-OBDII cable. So for $60 you'll have a proper tool. The next trick is reading and interpreting what the data graphs mean. They provide base-line graphs of a healthy engine to compare to. Takes some of the rocket science out of it. You may be able to detect a lean condition from O2 behavior (Lambda) or a twitchy TPS just observing the sensor outputs. The other option is getting a shop to perform a diag. with their spendy equipment to help narrow this down. A shop minimum fee can be less then the hundreds you may spend tossing random parts in.

You're describing your symptoms well but advise from member (guessers) can absolutely send you down the wrong bunny trails. You need to establish more facts before diving in. I had an issue where the car started but any demand (pressing the throttle) lagged terribly. It would magically clear up. Finally, the car would start-die-start-die and then would not start. The fuel pump was the bugger and that day, it would no longer spin up. Again, I was lucky that it croaked before I chased all the wrong things assuming it was okay. Don't wait for replies that tell you what's wrong 'cause we can't possibly nail it from a crystal ball. You have to pin down the issue either guessing with random parts or collecting facts such as fuel pressure readings, diag. monitor/logger results etc. Sorry, but it's really how much you are willing to investigate with the proper tools or reach out to a pro. Below is the logger software link. >>


Edit: Wow! Don't rev that thing that high (5-6K) without a load (driving). It's NOT good for the engine.

eeleaj 03-23-2013 01:14 PM

Thanks for the reply. Do you think I should look for a decent shop or a motorsports shop since my car is supercharged. Ill stop revving high when not driving thanks

White_Knuckles 03-23-2013 02:11 PM

Supercharged? Yikes! That in itself isn't my concern but suggests you or whoever put the kit in undoubtedly altered the stock DME fuel mapping (chipped or flashed the parameters), changed out the injectors, etc. This movie just changed as more variables from forced induction are present. Yes, seek an independent shop with experience with German cars. The base-line data for normal cars is useless in this case they should understand that. A tuner type shop may have a better clue what the affects and readings are from your modifications but your symptoms may be simply related to what stock engines would suffer from.

My concern is, if you have no history who/where the supercharger was installed you may be fighting someone else's problems. Let's assume all was performed correctly and program/injector alterations are healthy. The issue likely is external to this but you never know? The other thing is, whoever installed this probably drove the car hard racing around and now you're getting the pleasure of replacing what they hammered. I hope you can find assistance with this but certainly be aware some shops may not receive your car with a positive approach. I'd make a few calls qualifying the situation and don't accept the "well, we would have to look at it" replies. Service writers, you typically get on a call, just want to take your money to tell you they don't have a clue after the fact. Try to get to the actual mechanics to discuss the problem. Sometimes going to the shop is the best deal. They often will respond in person better than on a phone and you'll get a feeling about the shop looking around at the cars they service and talking directly with the mechanics.

Good luck brother.

eeleaj 04-01-2013 10:19 AM

Thanks for the reply. I installed the SC kit myself and sent my dme to active to get the tuning done on it. I havent driven my car hard at all. Im pretty sure its something external like a relay or something small that I cant pinpoint because the problem is intermitent and not constant. I took it to a shop but the guy kept trying to have me give him permission to rip out my supercharger kit to diagnose the problem. When I took my car to his shop it ran fine perfect idle and all. I just dont have any money at the moment to have someone tear up my engine and start guessing while charging me shop prices. I parked it at home for the time being. Im thinking of just selling the bimmer but not sure yet

White_Knuckles 04-01-2013 08:34 PM

I was thinking about BMWlogger software another couple guys are getting/using. A USB-OBDII cable and an XP (or above) notebook is all you need for hardware. The software can be downloaded free to scan and clear errors. For $50 they send you a key code for your DME registration. With the full software unlocked, the logging part would be a good tool to look at multiple sensor activity when it's pulling tricks. A plotted log can be compared to your baseline (healthy) system snapshots. You can see into what's going on to narrow the source. The price is cheap compared to other PC based diagnostic products I've seen. They however, often let you alter parameters (write values) where this is a read only tool.

You may have a issues with your DME being flashed where the PC software goes crazy showing false data? You're in a situation where more info. is needed from a diagnostics effort. Something is hiding in there. You could try the diags or contact the developer and see if the forced-air data reads accurately? Chances are it will see the sensors and be fine? At least you have the history with the modifications, that's good.


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