93 325i No Start when Cold.

Hi. Name is Paul. Longtime lurker, first time poster.

Here's one for you gurus.

Car: 93 325i, manual. 206k miles. No engine mods.

Story:
Ran excellent.. until last Thursday.
Started out as a longer than normal cranking time, but engine would fire on second or third attempt. When warm, car starts up immediately, as normal.

Sitting overnight, car has a long crank time (Think of a diesel in the winter with bad glow plugs). Again, once started, runs perfect, and when turned off and on (say running into a convenience store) it starts immediately, as normal. Over the weekend, toyed with it a bit. Hard to track down cold start issues, as once it starts, it will always start for a few hours.

However, it has gotten to the point where it'd take five or six attempts when cold.. To the point I am fearful of cooking the starter.

This morning, it finally wouldn't start at all even with several long cranks. I popped open the throttle elbow and sprayed some starting fluid. Car fired immediately and stayed running. I turned it off immediately, restarted, and it was fine.

Obviously I don't want to be driving around with a can of starting fluid. I already had a lawnmower like that.

Parts changed:

(I have an 80% complete parts car on the side that ran when parked in April).

Fuel pump fuse/relay/pump.. all check out - no difference.
ECT sensor for DME (new from other car) - no difference.
ICV > throttle body elbow hose (old one cracked, new on other car) - no difference.
throttle body elbow hose (old one cracked, new on other car) - no difference.
Plugs - boots (less than 1500mi on the other car) - no difference.
MAF (new on the other car) - no difference.

So rather than throw parts at this over and over, I'd like some opinions.

It's getting clichéd, but cam position sensor and crank position sensor. If you change one, change both. They aren't expensive, and you'll be in the same area where they plug in (a PITA location under the intake manifold...way to go BMW ). Long starts and/or no start with no fuel injector pulse is a symptom of a dying crank PS. No ignition pulse usually means cam PS. Either way, if the ECU doesn't see engine rotation on start attempt, it won't fire the plugs, or injectors, or both.

By the way, welcome to the fest, Paul.

I suspected it was either/or.

They may not be too pricey, but when the car itself was $1400.... .

In all serious it's a resto project for my girlfriend. I have on order all the heater/cooling hoses under the intake, and I was going to add additional incar gauges (oil pres volt vacuum) so I may as well do everything all at once.

Anddd the fun begins.

Give ALL those hoses a hard look before reinstalling them. In fact, if you can afford it, just replace them, especially the molded ones.

Good work on getting after it!

I have $250 worth of preformed heater hoses on the way already. Stupid "H" hose is $70 alone. I also have some ghetto (cheap) Sunpro gauges on the way, may as well set them up now.

Good job.

I know the feeling. I'm refreshing an M20 (2.5i) engine for a friend, and the "super hose package" was over $400, but every hose and clamp are now new (along with every bolt-on piece on the outside of the block. Many more $$$$$$$)

Well... After driving it for three days, I think it's fixed.

Replaced Cam/Crank Sensors

While I was there I replaced
ICV (good known clean unit... did make a difference in idle)
IM gaskets
TB gasket
ALL cooling hoses
Vanos hose
engine vacuum hoses
ALL fuel hoses in the engine bay (from/to filter and lines, AND the hoses on the intake)
Fuel filter

Car seems ok. I hate checking out 'cold start' issues.. But it no longer cranks forever/long. Been great, actually. I'll give it a few more days, but, I think it's fixed.

This sounds like the Exact same symptoms I am having on my Z3 with a S52 conversion in it. Same kind of starting issues. I replaced the Crank shaft position sensor. Now I am replacing the cam Shaft Position sensor after reading this thread. I pray it works.

That's gotta be the issue.