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E46 crank no start. Help

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12K views 17 replies 10 participants last post by  Ecss08  
#1 ·
Hello I'm new to the forum but not bmw. I have an e90 and just acquired an e46 04 325xi. A week ago my fuel pump went and had to replace it. Ran fine after the install but noticed a slight sputter now and then. Very random. Well today I noticed a slight lack of power I exited the highway and as soon as I removed my foot from accel it died! I was able to get it to start with my foot on the accel but as soon as I let off it would die. It cranks but no start of my foot is not on accel. I got it home, first thing I check was fuel pump. Seems to be ok... next I checked spark... got that! And I can only assume I have air lol. I don't know for sure if I have a vac leak. But I can't imagine a vac leak creating a no start. I have no codes except a MAP which is my therm. Also can't see that creating a no start. Any help would be awesome! I'm lost
Also I have PAsoft and all other bmw software. Still nothing helping me code wise... I did read someone saying about a clogged cat, but before I replace the cats I want to rule any other things out... please help! Thank you
 
#7 ·
Low fuel pressure and plugged exhaust should give more of an issue at higher RPM's and loads.

What is your MAP code #? If a MAP sensor sticks out of calibration it can cause a no idle issue.
Will you scanner give you sensor data or will it just read the codes?

If it will run just off idle... say around 1,200-1,500 RPM then I would check the idle air control motor.
First thing I would do after verifying it only dies at idle is to TAP on the IAC motor with the handle of a screwdriver to see if maybe it is stuck.

A large vacuum leak can cause this issue and set some MAP codes also.
 
#15 ·
When the car is off and cold, put the key in the ignition. Turn it two clicks to Position 2. All the electronics will turn on, including the fuel pump. You should hear the fuel pump prime the system over the first four or five startup beeps. If you don't hear the fuel pump prime, then either your fuel pump or fuel pump fuse is dead.
 
#16 ·
Was old plugs wet with petrol? Does it wets new plugs after 1-2 attempts of 5sec cranking? Can you smell clear petrol at exhaust after cranking? Does it start every time when holding foot on accelerator and does it start straight away this way or splatters and and coughs on individual cylinders b4 starts to run without starter motor?
 
#17 ·
While cranking the vehicle spray some carb cleaner thru the throttle body, you be the injector. If it starts and runs for a second or two it's a fuel supply issue and you will need to diagnose that.
If it does not run it could still be a fuel issue but most likely not.

Fuel supply issue possibilities
- Fuel pump not running due to a bad pump, no voltage to pump, no ground from pump, engine computer not telling it to turn on
- Fuel injectors not firing due to engine computer not telling them to turn on, no voltage to injectors
- Antitheft issue,
and more....

Step back... figure out what you do and don't have... Fuel, Spark, Compression.
Think about what would cause what ever is missing to stop and test what you can with the tools and knowledge you have.
This will narrow it down so the $$'s spent will be wise