ENGINE WONT START?

The E-box under the hood has a fuse block, check there and let me know. It is under the right side cabin filter housing. When you turn the key to the on position without cranking the engine over can you hear the fuel pump run in the tank for 5 seconds?

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down this guide and report back.

My observations shortly before my problems started....I noticed I lost power and accellaration followed by a poor running engine like a missifiring engine with bad sparkplugs which continued for about 500 yards ....so I pullled over to side of the street and turn off the engine for about 10 seconds and restarted ....the car ran smoothly for about another 1000 yards then went back to runnning like it did before restarting...so I pulled over once again to try figure out with what could the problem using my little knoledge about cars and motorcycle to try analize what it could that is causing the problem....I first thought could be gas bad plugs......so i decided to to get the car towed home before sundown and address the problem the next day....however i discoverd or was convinced that I did had bad sparkplugs but I inssisted I still would like drain my gas after being offerd a solution by a sales person at autozone to try some lucas gas formular mixed with approx. 16 onz.of mystic oil to 1/2 tank .....and after doing that I try to start the car and the results were the same so rocked the tank to mixed the fuel a bit .....so when I restarted the car I heard this knocking noise coming from the enging with the hood open seem very loud......so i would like to drain the gas and replace it lead free fuel ......but now i'd like locate the drain plug .....can you help me

Fuel quality could certainly be at the cause of this problem. There isn't a drain in the tank, you will have to pump it out, if the fuel is contaminated. The problem may be something else, have you had the car scanned for faults at your BMW repair facility?

hello, I have ingtion but the bmw won't start?

Do you haver fuel pressure and injection pulse?

mark (mhpautos)

N0, and I change the computer.thank you jusonac2

EWS might need realignment.

As previously said, car stood for three years . Last week car started and stalled. You where correct about it passing through (blockage) now before i could replace fuel filter the car has done the same. Now it refuses to start. On the dash it indicates on the idling gauge if it would start, but sometimes the gauge moves when trying to start other times the gauge (most of the time) does not move. My assumption is that the jets are blocked and no fuel is going into the carbs. help me.

Hey Neil,

If the tachometer is not moving it sounds like the crankshaft angle sensor is not working. Can you check to see if the the car has spark?

Follow this guide

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Please run this test and get back to us so we can continue helping you.

Best, Ken

Electrical problem
1994 BMW 525i 6 cyl Two Wheel Drive Automatic 125k miles

Replaced DME in my "94 525i but I still having the issue of starting. The tech who worked on the car said that the new DME has to be dealer programmed and thinks the problem is a result of faulty alarm. The fuel pump and relays work fine but no fuel signal. Any suggestions

Thank you

What was the original problem?

The car cranks but does not start. Fuel fuse failed testing light.

Did you check the fuel pressure and delivery? If it is popping the fuse for the fuel pump, I would think that there is a good place to start. Remove the pump from the tank and test it, if it pops the fuse, replace it. Go to Realoem.com for a great exploded view and parts pricing. Look in the 16 section for fuel delivery.

The fuel pump works. The car would not start even with starter fluid. Thx

What was the DME replaced for in the first place?

Car won't start I used a code reader for my 1994 BMW 525i and the code said 1A which means control unit supply what does that mean?

that means that the ECM isn't seeing battery voltage. make sure the battery is fully charged and then check ALL the fuses preferably with a test light or meter. sometimes they look good but arent

I have a repair manual but it does not tell me what I need to know. Whenever battery is connected, main relay is energized. Fuel pump relay not energized. These lights stay on all the time while battery is connected: battery light, check engine light, oil light, and park brake light. When park brake is released light gets dimmer. Have changed all accessible relays and the DME. Still no change.

Which repair manual do you have? I always buy the Robert Bentley publications, they're the best. Has anything happened to the car? Fire, theft, accident, hack stereo or alarm installations, wrong components? If the main relay is pulling in then you have a problem in the steering column. Do this, drop the under dash from the drivers side and the surround from the steering column to access the ignition switch and disconnect it from the lock. Then the insertion of a screwdriver in the switch should allow you to start the car, and of course shut it off too. The steering column will need to be removed to effect this repair, are you up for it?

Replaced normal speed relay. This cured the constant instrument cluster lights and main relay being on all the time. Back to original problem. Fuel pump relay not energized. Relay is new. When starter fluid is sprayed into throttle body, car will attempt to start. Changed out DME, no change. Check engine light is not lit.

Is there a spark at the plugs?

Car apparently has spark, because it will try to start when starter fluid is sprayed into throttle body. Not getting fuel. Fuel pump not being energized.

I ask if there is spark at the plug so that I know if it exists, no assumptions please. Inspect for a hot blue spark at the plug. If there is a spark then there should be an injector signal. Then the reason why the pump is not receiving power can be better determined, it is either a fuse or a relay or the wiring to the pump or the pump itself. Locate the fuel pump relay socket and insect for the green wire with the purple stripe, that is the power wire to the pump. Put battery voltage to this wire and see if the car starts and runs, or you can lift the rear seat base out and power the pump up there, it is on the right side.

This happened to me I had to put a new
ECU in brain box got it off ebay or you really
may get by with grounding your existing box better

1992 525i will crank but not start. Power from the DME relay but low power going to fuel pump relay; and no power to fuse. Is this an alarm issue?

Sorry about the delay in response, new site de-bugging is what it is. As to your question, the possibility that there is intervention from the OBC or drive away protection could keep the DME from allowing spark to happen or the fuel pump to run. What events preceded this no start condition?

Thanks Dr.Hagerty for geting back to me. It started out with the trans program light coming on,but the car shifted fine and even the selector switch would still work. I drove it like this for about 2wks. Then I started my car,on a cold night and it stalled. Started it again and stalled. Then I got it to stay running,running rough though and proceeded home. It kept wanting to cut out if I let off the gas and the engine light would flash,but not stay on. I made it home and tried to start it,no start. I have power @ the relays and I jumpered power to the pump fuse,pump runs but no start. I hope this helps and thanks again for any help you can give me.

OK, lets go with the basic stuff to begin with. The fuel pump runs and makes pressure, you need to check that it indeed does make pressure. There is spark, pull a coil and confirm that this is so. There is an injector signal, pull the connectors off the injectors and check for power and that the DME is bringing the other side to ground, it should flash a noid light (or a 5 watt side marker bulb, it's cheap and you can borrow one right off the car) If it does not do all of those things, let me know and we can proceed.

Hello again. I finally got back to working on the 525i,due to a host of time issues. Anyway, I have fuel pressure,when it's jumpered.I changed the crank sensor,still no power to the fuel pump fuse. Also,no injector signal. I noticed a drycracked/burnt wire,assuming it's a gound at the front of the head,just under the removing hoop? Could this be a ground issue? Cam sensor? I'm lost and need your help. Thanks

I cant tell what you are looking at by the descripton. It does sound as if you have the problem identified.

Good news,my bmw is running again! After I installed the crank sensor,I never thought about resetting the computer and since the battery voltage was too low for it to take in the new info,it didn't start. I unhooked the ground of the battery and charged it,which was long enough to reset the computer. With a fully charged battery,turned the key,didn't hear the pump kick on and got worried. I turned it to start and it fired right up,ran a bit rough @ first,but cleared up. I've put about 300 miles on it since:) Great to have it back! The trans program light is still on,shifts just fine though. Can I reset that or is this a dealer issue? Thanks Dr.Hagerty for all the help!

The trans light is a different issue. It may require rechipping the EGS module.

someone put sugar in my gas tank, so ive replaced several parts on my car so far.

-fuel filter
-fuel pump
-cleaned tank
-catalytic converter
-$30 worth of gas in the tank

AND IT STILL WONT RUN!!!

the fuel pump is getting gas to the carburetor, but it wont allow it to fire up. when i first started getting problems with my car, i had all the above replaced and worked on. & then it sat for a while. well i eventually ended up taking my radio out my car. & then i let my mother use my battery out my car. so im wondering if maybe my car alarm system locked up on me because my security light under my hood blinks and makes noises with or without my keys in the ignition.

Disconnect the alarm and see if it starts.

& how do you do that?

If it is the OE factory alarm, just remove the edge connector to the alarm module. If it is an aftermarket alarm, it will probably require you to do some due diligence to find out how to defeat it.

Ive replaced spark plugs, coil packs,and checked all fuses and Im getting no spark. What would you recommend?

No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor /distributor pick-up coil, ignition control module, ECM,Ignitor camshaft and crankshaft sensors- Note: If it doesn't apply disregard it

1991 BMW525i Won't start.. like its out of gas, but not out of gas.. could it be a fuel cylanoid? and if so.. where is this cyanoid located?

If its cranking over and w/n start, determine if its fuel or spark problem-Do below

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it and keep testing