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03 525i will crank but won't start

9K views 15 replies 7 participants last post by  bmac50 
#1 ·
I changed the spark plugs and the crankshaft position sensor, the fuel pump appears to be running checked the fuel rail and get a nice burst of fuel. its wants to start but just won't. Please Help!!!!
 
#2 ·
Was it running before you did the work? Why did you replace the crank sensor? Was it OEM? Did you measure the clearance to the flywheel?

What are the stored codes?
 
#3 ·
Hey edjack, Yes it was running before. The plugs were 10 years old and needed replacing, there was also a bad valve cover leak. Went ahead and repaired these issues first. And yes the crankshaft sensor was OEM took the old one with me when I got the new one, exact match. Tried the sensor because if the ECM engine control module does not receive a signal from the crankshaft speed sensor the during cranking the engine will not start. It was worth a shot
 
#8 ·
Novice

Yes Iam a beginner at this, but Iam resourceful enough to listen to people who have more knowledge about these cars. I ordered a code reader an will start with that. The repairs (new plugs, valve cover gasket) were needed before I ran into this problem. The crankshaft position sensor only cost $48.00, so far that's not a lot of money. Since reading the few responses, I will first of all get a code reader (on the way), once this is done I'll be back to report on what codes turned up. Thanks edjack, and fudman for your input and hopefully I can solve this problem without getting the shaft from my local so-called Eurocar specialist.
 
#10 · (Edited)
Codes

Got the code reader and it has the following readouts: P0102 Mass or Volume Air Flow Circuit low input, Po491 Secondary Air Injection System Insufficient Flow banks 1 and 2, PO1347 thru PO1353 Misfire Cylinder 3 to 6 with fuel cutoff. Pulled plugs and they were wet from gas. Check MAF filter looks clean. Where do I go from here?
 
#11 ·
Kind of a shot in the dark, but it sounds like a massive air leak on the intake. Double check the boot from the MAF to the throttle body for cracks. If you removed it or even disturbed it while getting to the crank sensor, it is very possible to open up a crack. Also double check that the smaller branch of the boot is actually connected.
 
#14 ·
Thanks for your reply diggyd357, but you can go buy 10 oem cps, all I needed was one that works (for $48.00). You can go buy all the TRUE OEM's you can afford. Maybe you like paying more for the same thing, besides that maybe they cost more where you live and maybe I know someone who can get OEM cheaper. Thanks for your help.
 
#15 ·
Look man, I was just trying to help you out.... I JUST dealt with a cps issue. If you do your research you will see that many places claim to have oem parts when infact they are not. I was a long time non believer in spending extra money to buy oem until I found myself having to go back and buy a $ 100 oem sensor to replace the $ 50 sensor I had just bought and lasted all of 8 days. Or the $ 40 non oem ccv that fixed one issue while creating others...in the end an oem ccv fixed all the problems. Asked around here....oem does matter, ESPECIALLY when it comes to sensors. Research your parts before you buy something advertised as "oem" and try not to get so offended when somebody here takes their time to give you advice. Me... I'm nobody, fairly new myself, but be careful not offend a "somebody". You won't find a better forum with better people that give better advice.
 
#16 ·
thanks for the lesson diggyd357, you gave me info about a crankshaft sensor, do you have any other suggestions besides educating me about OEM? If so Im open to them. Don't have a attitude with you, just wish you were more informative instead of pinpointing the price of a crankshaft sensor. If it goes bad I will deal with that when it happens, right now it is a non issue. Thanks for taking the time to reply and I will remember what u said about TRUE OEM.
 
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