M10 does during idle and won't start back up

[cgk_iii]

Got a 84 318 that was running solid but now won't start. Changed the valve cover gasket and did a icv delete and everything was fine afterwards. Later on that night i started her right up and when letting her warm up she dies and won't start back up. I suspected it was the fuel pump since i dont hear it coming on anymore. Sprayed some carb fluid in the intake. Nothing. Getting spark but no fuel/air delivery. When checking the vaccum ports we found out there is no suction when cranking the motor. Im stumped. Any help is appreciated. Still learning about the m10 so bare with me.

Thanks in advance

[cgk_iii]

Bump

[cgk_iii]

Up

[thebutterson]

Well if you can't hear your fuel pumps you should start there. Check for power at the relay and jumper it to see if they come on. You can get a wiring diagram from here: http://wedophones.com/BMWManualsLead.htm. Also check that whatever you used for your ICV delete didn't come loose or fall out.

[cgk_iii]

Im headed to the junkyard tomorrow toget a fuel pump (temporary) to see if that fixes the issue. There is power to the relay. If it is the pump why would it cause the vacuum lines to have no suction while cranking the motor? All the plugs were in place.. Also tried reconnecting the icv to see if that made a difference but it didn't. Ill update tomorrow after replacing fuel pumps

[Jaxx_]

air fills cyls fairly fast... at cranking RPM I don't think that you would have very much vac.

Also, power to the relay doesn't mean that you have power to the pump. Check power at the pump before you waste your money buying a possibly bad fuel pump from the junk yard.

I don't remember much about L-Jet, but if you don't have spark and you don't have fuel, then a logical assumption is that the ECU isn't sending any signals to do either. If this is the case, it could be as simple as a bad sensor (timing, air, etc). But it's probably NOT the fuel pump if you can't get it to spark. Let's not assume that two parts failed at once, that's too much coincidence.

[cgk_iii]

Spark is there for sure. I dont think timing is the issue either. I agree with testing the pump first, which is what i was planning on doing. I would rule it out to be the ECU if i wasn't getting any spark as well but that's not the case. Ill run some more tests tomorrow an see whats up but as of now it seems to be the fuel pump.

[E30_Pare]

Dont forget there is an inline pump under the car and an in-tank pump. I'd swing for a clog fuel filter (in the engine bay). Basics: check the fuses.

Wouldn't be surprised if it was the fuel pump as I went through many with my m10. Also check if the afm door is sticking. Just stick your hand in there and manually move the door open then try to crank. If none of that works pop off the cap and see if the rotor flipped 180 degrees. Probably unlikely, but has happened to me once.

lastly vacuum leaks.

[Jaxx_]

Sprayed some carb fluid in the intake. Nothing.

Spark is there for sure.

wut

[cgk_iii]

wut

Just bc there is spark doesn't mean carb fluid is going to make her start right up.

[cgk_iii]

Dont forget there is an inline pump under the car and an in-tank pump. I'd swing for a clog fuel filter (in the engine bay). Basics: check the fuses.

Wouldn't be surprised if it was the fuel pump as I went through many with my m10. Also check if the afm door is sticking. Just stick your hand in there and manually move the door open then try to crank. If none of that works pop off the cap and see if the rotor flipped 180 degrees. Probably unlikely, but has happened to me once.

lastly vacuum leaks.

This is the kind of input that is helpful. I already checked the AFM door and checked for any vaccum leaks. Im rulin out the verdict to be the fuel pump. Ill be replacing the pump along with the filter and will post updates tomorrow. Thanks man.

[Jaxx_]

Just bc there is spark doesn't mean carb fluid is going to make her start right up.

But doing nothing? I would assume it would at least sputter or try to fire. Are you sure you have spark? How did you test it?

[cgk_iii]

But doing nothing? I would assume it would at least sputter or try to fire. Are you sure you have spark? How did you test it?

Sorry looks like were misunderstanding eachother. But to clarify, yes it did sputter. I checked to see if there is spark by sticking a flat head in a spark plug wire

[Jaxx_]

Sorry looks like were misunderstanding eachother. But to clarify, yes it did sputter. I checked to see if there is spark by sticking a flat head in a spark plug wire

Cool. Since you know you have spark and no fuel, check that the injectors are firing. You can do this with a 12V LED to a injector connector. Try to start the car and if it flashes at all you have an issue with fuel actually reaching the fuel rail--in which case the diagnostic of fuel pump (inline or tank) is probably correct. The next step is to check for battery voltage at each pump when trying to start. If they are both getting power you need to see which one isn't running. Then replace it.

I doubt that a fuel filter would cause a catastrophic failure like this(no start). The fact that it died during idle is something to consider in itself--so I wouldn't start looking at things that fail slowly (although irrelevant to the situation--spark plugs, fuel filter, etc)

vac leaks, unless massive(and even if they are massive I'd still doubt this), won't cause the car to not fire at all.

[cgk_iii]

So im looking for a new fuel pump an came across a universal fuel pump from Bosch for 50$ shipped. Idk if anyone has experience with the universal pump? Should i steer away or try it out?