M50 Wont Fire.. At All

[5Toes]

Things I know for sure

- Have strong spark
- I can smell fuel out the exhaust pipe
- I have pulled plugs and tested 3 separate coils for spark, all checked out good
- Pulled fuel supply line and jumped fuel pump, steady stream comes out
- New spark plugs
- Cleaned ICV and new plastic connector.
- Vacleaks are possible, but if there are any they are very small. All intake mani gaskets looked good, as did TB gasket.
- Painted Valve cover (not sure if it would affect coil pack grounding or something)
- New spark plugs (NGK BKR6EK)

Engine ran fine a few weeks ago, and then one day went to start it and it wouldnt stay running and backfired. I pulled intake to clean ICV and also did the valve cover gasket and cleaned the intake manifold.

I am stumped. Neighbor says it sounds like it has no/little compression, but I highly doubt that could be the case.

any ideas?

[emmanuel.dlc]

stuck open injector?

[5Toes]

It doesnt fire at all is the problem, if one were stuck open that atleast the other cylinders would run right?

[emmanuel.dlc]

not necessarily, it would get flooded and fail to start. at least that's what happened to me

remove the rail, and coilpacks (to avoid any spark close to the fuel), try and start and you'll see the open one if any...

have a fire extinguisher handy

[Cyrix2k]

it will start on less than six cylinders so if one were stuck on, it should either run or hydrolock. You need to check for FAST - Fuel, Air, Spark, and Timing. (Carefully) Shoot some starting fluid into it and see if you get it to start or at least pop. Be sure to have two fully charged fire extinguishers standing by. Even if the compression were low, it would start. Given that it was running not long ago, I think it's something similar - either a lack of fuel or no spark. You would need a catastrophic failure for it to lose compression so severely as to not run and you would know if that happened. Also check your throttle body boot & ICV hose after the MAF for leaks. Large air leaks will keep it from running. You can also troubleshoot this by disconnecting the MAF and trying to start it - it will run without a MAF.

[5Toes]

Alright, I will look into it.

This thought of no compression is scaring me! I dont see how that could be the case though, the motor pulled good before I parked it to drive the other family car for a few days.

I cant read out codes either, which is bothering me. Check engine light is on though so DME is good of course. This is on a E34 by the way

[EN318isPDX]

Things I know for sure

- Have strong spark
- I can smell fuel out the exhaust pipe
- I have pulled plugs and tested 3 separate coils for spark, all checked out good
- Pulled fuel supply line and jumped fuel pump, steady stream comes out
- New spark plugs
- Cleaned ICV and new plastic connector.
- Vacleaks are possible, but if there are any they are very small. All intake mani gaskets looked good, as did TB gasket.
- Painted Valve cover (not sure if it would affect coil pack grounding or something)
- New spark plugs (NGK BKR6EK)

Engine ran fine a few weeks ago, and then one day went to start it and it wouldnt stay running and backfired. I pulled intake to clean ICV and also did the valve cover gasket and cleaned the intake manifold.

I am stumped. Neighbor says it sounds like it has no/little compression, but I highly doubt that could be the case.

any ideas?

Are you sure you hooked everything back up correctly?

[5Toes]

I double checked today.

ICV is humming so thats good. TPS is plugged in properly for sure because thats the only plug that goes that far.

Coolant temp sensor and gauge cluster sensor are right. Fuel lines are good for sure.

[EN318isPDX]

- Painted Valve cover (not sure if it would affect coil pack grounding or something)

This made me LOL so hard milk came out my nose. Seriously why are you pulling apart engines if you don't understand basic electricity?

Also I have told you this multiple times. This is a 24v swap section for E30s, not basic engine troubleshooting please move to another section or forum plz kthx

[5Toes]

LOL, I know how electricity works, but I thought I would add that to let everybody know everything I have done.

[MaksV]

Check the crank sensor, and wire, plug - if you have FAST then this is the next point of issue. You can rent a compression tester if you think its an issue, but i have had engines start with very little compression or at least pop.

[5Toes]

I havent checked the crank sensor yet because I have spark, so that rules that out I believe?

[EN318isPDX]

I havent checked the crank sensor yet because I have spark, so that rules that out I believe?

Are you qualified to make these sort of assessments? Seriously dude have you ever used a multimeter?

Really though how is this related to a 24v swap e30?

[5Toes]

Yes I have used a multimeter. I thought BMW's only supply spark if the DME sees a reading from the CPS.

Its not related to an E30, so whats the problem?

[EN318isPDX]

Yes I have used a multimeter. I thought BMW's only supply spark if the DME sees a reading from the CPS.

Its not related to an E30, so whats the problem?

You need to start posting these basic 5 series engine problems here
LOOK JAMES MADE A SPECIAL 5 SERIES SECTION JUST FOR YOU!
"E34/E28 Forums General 5 Series Technical" sounds like where you should post