99 328i starts then stalls.ughh

[99E46drv]

Ok let me start by saying hello everyone im a new member so if im posting out of place please excuse me and point me in the right direction,knowledge is power✊. Ok last tuesday i was on my way tonthe dentist boom heater pipe exploded 20yr old plastic right.. So I tow it home drove it off the truck parked it. Removed intake manifold, replaced said exploded pipes. Replaced VANOS with rebuilt unit with anti rattle very nice,Replaced ccv and hoses,replaced spark plugs with ngk v powers not irriduim and die elec greased plug boots for easy removal next time, replaced vacuum hoses all of them and capped off outlets that were leaking prior to repair.... replaced valve cover gasket, replaced coolant hoses,cleaned all surfaces and applied spray a gasket lightly for good measure on intake gaskets,throttle body, and replaced disa oring and intake manifold gaskets. Completeled throttle body relearn for the hell of it. I filled her up with pentafrost and prurple ice. Turn the key.......💔 Car will start then die immediately so i removed the intake checked literally every single inlet,hose,vac line etc..Replaced camshaft position sensor intake side, Reinstalled car still starts then dies....sprayed fuel out of spray bottle in my intake boot.... voila which means and then i found out the car starts idles rough for a minute but then stays running.revs great sounds better than ever before, then after i shut it off problem returns. Replaced fuel pump with known working one from my 03 330i same thing... Checked for fuel leaks ,nada. Im sure someonw has had this issue and or completed a successful diag and repair of said issue. Any help would be appreciated as its my only car now since my wife left me and took my 323i with her........ Have been bumming rides from my assistant manager for a week lol. Thank you in advance.

[Breeze1]

Ok let me start by saying hello everyone im a new member so if im posting out of place please excuse me and point me in the right direction,knowledge is power✊. Ok last tuesday i was on my way tonthe dentist boom heater pipe exploded 20yr old plastic right.. So I tow it home drove it off the truck parked it. Removed intake manifold, replaced said exploded pipes. Replaced VANOS with rebuilt unit with anti rattle very nice,Replaced ccv and hoses,replaced spark plugs with ngk v powers not irriduim and die elec greased plug boots for easy removal next time, replaced vacuum hoses all of them and capped off outlets that were leaking prior to repair.... replaced valve cover gasket, replaced coolant hoses,cleaned all surfaces and applied spray a gasket lightly for good measure on intake gaskets,throttle body, and replaced disa oring and intake manifold gaskets. Completeled throttle body relearn for the hell of it. I filled her up with pentafrost and prurple ice. Turn the key....... Car will start then die immediately so i removed the intake checked literally every single inlet,hose,vac line etc..Replaced camshaft position sensor intake side, Reinstalled car still starts then dies....sprayed fuel out of spray bottle in my intake boot.... voila which means and then i found out the car starts idles rough for a minute but then stays running.revs great sounds better than ever before, then after i shut it off problem returns. Replaced fuel pump with known working one from my 03 330i same thing... Checked for fuel leaks ,nada. Im sure someonw has had this issue and or completed a successful diag and repair of said issue. Any help would be appreciated as its my only car now since my wife left me and took my 323i with her........ Have been bumming rides from my assistant manager for a week lol. Thank you in advance.

Hello and welcome to the forum! When you sprayed fuel in the intake boot and it started, how long did it stay running? Like as long you wanted it to or for a limited time?

[Breeze1]

You've changed so many things at once that it makes the diagnostic a bit difficult to establish. But if the car starts when spraying fuel into the intake boot and runs great past initial rough idle, it seems safe to rule out the following:

- MAF
- Fuel Pump
- Plugs
- Coils
- O2 sensors
- ICV
- Vacuum leaks

Here's just a hunch, based on: "greased plug boots for easy removal next time".

Grease is getting into the combustion chamber and impairing mixture/electrical connections --> startup. But once you "force" more fuel in through the intake boot to help it start and the engine warms up, things get better.

If I were you I'd take the plugs out, clean them as well as the coils + plug wells with a dry cloth and drive the thing. Since it behaves well past initial startup I'd seize the opportunity to make the thing run, warm up properly and help it get rid of any dirt that could have gotten in.

[99E46drv]

I put a pea sized amount in the coil boots on each plug.. Anyway after working on it for 2 late nights i discovered this morning that my MAF sensor was the culprit... Day one bmw diag lol unplugged it started right up. Just had a hunch as i remembered last night when i did have it running the trans was in safe mode... So this morning i unplugged it and bam instant ignition so thank you for the info and help. Sometimes it's the most simplistic things that can cause the most pita situations... Either way thank you for replying with your input and it is valued. I will try cleaning it today at work and if that doesnt fix it the i will purchase a new one..craziest thing is i bought one for the 323i i had which i bought from get this autozone😂😂😂😂 a duralast maf and they work flawlessly...

[Breeze1]

Good to hear that the issue was resolved easily! TBH I'm a bit dubious about the MAF being the culprit because usually when that's the case you can't rev the engine up without it coughing/sputtering, and the fact that things get sorted when it's unplugged can also point to a vacuum leak (but then again, revving it up shouldn't be that easy).

But hey, as long as things get fixed that's all that matters!

[dworthy]

+1

As a side note, the dielectric grease is okay to put on the boots of the sparkplugs, just don't go crazy with it is all.

[99E46drv]

Yeah i usually put about a pea sized amount in each boot just to prevent damage to coils if i need to remove them again.. It was running fine before the repair which had me stumped lol. Bought the car for 250 bucks from a kid that didnt know a thing about cars.. It had a cracked intake manifold every vacuum hose was leaking, it had a bad maf, a cheap cone filter clamped to the maf lol no air box at all... Needed all window regulators needed ccv as it was gone lol guy had jb weld all over the intake smh... So i replaced the entire intake with one from an M54 custom mad an adapter for the throttle body with a drill press and a tape measure out of a quarter inch piece of aluminum. Replaced all the window regs, complete ac overhaul, changed nasty grey interior to black from my parts car, dinan exhaust upgrade, cold air intake long tube with k&n aftermarket air box and aluminium ducting to ram air inlet in bumper, 330i fuel injectors,aluminum interior trim, big brake kit, h@r lowering springs front and rear, clutch fan delete replaced with manuel coupe elec fan, aux fan delete installed aftermarket 10in fan to push air through condensor, headlight retrofit projectors and halos and everything ive just done.. And still working on it

[Breeze1]

Yeah i usually put about a pea sized amount in each boot just to prevent damage to coils if i need to remove them again.. It was running fine before the repair which had me stumped lol. Bought the car for 250 bucks from a kid that didnt know a thing about cars.. It had a cracked intake manifold every vacuum hose was leaking, it had a bad maf, a cheap cone filter clamped to the maf lol no air box at all... Needed all window regulators needed ccv as it was gone lol guy had jb weld all over the intake smh... So i replaced the entire intake with one from an M54 custom mad an adapter for the throttle body with a drill press and a tape measure out of a quarter inch piece of aluminum. Replaced all the window regs, complete ac overhaul, changed nasty grey interior to black from my parts car, dinan exhaust upgrade, cold air intake long tube with k&n aftermarket air box and aluminium ducting to ram air inlet in bumper, 330i fuel injectors,aluminum interior trim, big brake kit, h@r lowering springs front and rear, clutch fan delete replaced with manuel coupe elec fan, aux fan delete installed aftermarket 10in fan to push air through condensor, headlight retrofit projectors and halos and everything ive just done.. And still working on it

Sounds all great (done a few of those myself), but the 330i injectors:

1) are useless in your case because the stock injectors are capable enough for your current setup
2) need to be tuned accordingly because currently your DME is using the 328i's injection tables, which are made for injectors of smaller capacity. Therefore your engine is overfuelling, resulting in a poor gas mileage and, on the long run, damage to cylinder bore (the excess of fuel will wash away the protective oil layer).

[99E46drv]

Had vehicle tuned for m54 intake and injectors with CAI and Exhaust

[Breeze1]

👍

[99E46drv]

May I also add im running performance igntion coils to compensate more fire for the fuel increase also why i added custom CAI to give the Vehicle more air since the m54 intake ports are slightly larger that the m52tu28. But with tune i have accomplished getting the full gain from the modifications and it is a completely different animal. Long tube CAI and DINAN freeflow exhaust definitely increased my low end torque curve and the m54 intake conversion increased my top end power at this point im happy with the performance as it is my daily and Didn't want sacrifice reliability, and fuel economy as much as possible as my foot gains about 100 pounds while listening to metallica..strangest thing

[Breeze1]

Performance ignition coils and larger injectors would be recommended (more the latter than the former as I don't think stock coils lack power) in case of forced induction. But as long the car is tuned for the injectors they can't hurt anyway...