LOOONNG starts

[e30ks]

I’ve got a 89 325i and about a month ago my car started taking a really long time to start, like 15 seconds long. It only does this when the car is warm. I replaced the engine temp sensor because i thought it was stuck on cold start injection. I also suspected a leaky injector but it started up fine after about a week of sitting. what is the next best thing to do? check fuel pressure, replace fuel filter, or is it something else that could be happening? The biggest thing that confuses me is the car still performs good, only problem is the super long crank time.

[e30davie]

I'd be looking at vacuum leaks, as if its sucking air it might be too lean to fire easily. But when its cold the cold start enrichment makes up for it and it starts ok.

[e30ks]

i already did a vacuum leak test and fixed them recently

[82eye]

i already did a vacuum leak test and fixed them recently

check your fuel pressure at the rail.

[packratbimmer]

All of my 325i cars have been like that in warm/hot weather - I just live with it. They always start. Maybe the fuel rail vaporizes or something.

[jbontke]

I am with 82eye, check the fuel pressure. What is it when you start cranking? After the car starts, what is it? When you shut the car off, what is it?

[packratbimmer]

Also make sure your are retaining residual pressure. If you are losing pressure after shutting the car off perhaps because of a leaky injector or bad check valve, hard starts can occur.

[laidback93]

Also make sure your are retaining residual pressure. If you are losing pressure after shutting the car off perhaps because of a leaky injector or bad check valve, hard starts can occur.

I definitely recommend inspecting the check valve on your fuel pump. I had extremely long starts after replacing my fuel pump. Turns out there was a bad batch of fuel pumps a few years ago and the check valve cracked shortly after installing it. I replaced the pump and it starts up almost immediately every time, hot or cold.