Intermittent No-Start and Stalling

[MavMan74]

Hello, I've been having a rather odd situation that just started to happen to me. Driving to work while idling at a traffic light, lost a little rpm and it stalled on me. It started right back up, no problem. So I was thinking something in the ICV area, but when I was leaving work it was having a real hard time before it started. No stalling on the way home however. This morning it would not start what so ever. I should of tried to smack the tank, but I didn't. Came out a few hours later and it started right up. Took around the block for a drive, and it did stall at one light.

So now I'm thinking its possibly the Fuel Pump. I checked the vaccum hose going to the FPR and no gas was found. When the car runs, it runs fine. It idles decently before it stalls. Any other possibilities? I am assuming since it eventually starts up, the relay is good as well as the fuse. I have spark/air/compression since it does run fine. Fuel Filter was replaced roughly a year ago.

Any thoughts? I do not own a Fuel Pressure Tester currently or else I would "T" in and check pressure at idle and everything else. Any input or ideas would be great. Thanks

[MissReece]

Hey, I had the same problem with my baby. I changed out her spark plugs first with no improvement. So I checked all the fuses as well as the main and fuel relays, they were all in great shape. I switched out the coil pack, but to be honest I don't think it was necessary, and she still didn't want to start up.
I finally got a new fuel pump and after a couple of minutes of trying to get her to start, she did. I was extremely excited right up to the point that she stalled on her own. Now every time I pump the gas, the engine dies. So I think I need to change the filter, but the fuel pump was definitely a major part of the problem.
When you turn the car on (just before you try to start it) does the fuel pump make any sound? Mine didn't make any sound at all.
I will be changing out my fuel filter today. I will let you know if my car is running after that. If so, then you are most likely looking at a fuel pump issue just as I was. If she doesn't run, I will let you know the steps that I take to resolve the issue. I would really like to know if you get yours running and what you did if change the fuel pump and that doesn't happen to be your issue.
I apologize, I know this was a long reply, but I have been working on my car for months now and it has been interesting to see how many other owners have had the same issue and realize that it is the fuel pump or relay 80% of the time.

[MavMan74]

Well the car does actually run. But like I said, it just didn't start for me in the morning and it stalled on me while idling at a light later that day.

However, I tried to start he car this morning and yet again, it doesn't want to start. Which is funny cause it started fine yesturday around lunch time and I drove it around the entire rest of the day with no issues.

My next attempt is to go and try and start it after it has sat for roughly a half hour and see what happens. If it doesn't run, but just turn over, I'll try and hook a fuel pressure gauge and see where its at.

At first I was super sure its the fuel pump, but now I'm having other fuel related thoughts. But I do still believe its a fuel issue, seeing as it runs fine in the afternoon.

[MavMan74]

Update

Ran out to my car and tried to start it. It would just sit there and crank. So I held the throttle to about 60% and cranked the car over and it started after about 10seconds.

So I was thinking it would be good to go ahead and clean th ICV and see what results I had. I put it all back together and took it for a spin. I could notice right away the idle was a lot smoother and it didn't feel like it would stall out on me.

I guess now the test will be tomorrow morning. Hopefully this will fix my issue.

Oh and a side note, I did check ICV resistance and its roughly 40-45ohms on the outside pins and about 22ohms checking the center to both outside pins.

[MavMan74]

Mini-Update

Well it has been raining all day so I haven't been able to check fuel pressure.

I drove it around in the morning with no problems. Took it to work and it started fine and everything. However when I was leaving work, it stalled at a light just about half a mile from where I work.

I'm still going on the thought of a fuel delivery issue. I will try and test it tomorrow morning and hopefully get an answer. I'll post my pressure numbers with KOEO, idle, and then maybe a slight rpm (1500-2000).

Hopefully this thread will help some of you guys when I find out my problem.

[e30Squid]

Sounds to me like its a Main Relay(DME relay) or CPS (Crank position sensor) problem. Do you have a 325i or 325e? If you do a search on this, you will see that both of these components are known to cause intermitting no start/stall issues.

I actually carry a spare main relay in my glove box just in case I run into an issue....I hate chasing problems just to find out its something simple. (In the world of Porshe 944s everyone carries a spare DME relay in thier glovebox) If the Main and Fuel Pump relays are the originals I would just replace them for good measure....they are not that expensive and you can keep the old ones as spares in case of emergency.

My car left me stranded for the first time a couple of weeks ago...the problem was intermitting for about a week (stall at lights, hard to start, etc.) and eventually it wouldn't start, and I had to call a tow truck. When I got home, I checked and there was no spark (I tried a spare DME that I have- didn't fix the problem) and then ordered a CPS from Rock Auto....She's running great now!

If you can, when the car is not starting pull a spark plug and see if your getting spark?

My other theory is that if I am going to be installing parts...I will start off with the less expensive and easier to swap parts first.

Best of luck!

[MavMan74]

Well it started fine this morning if I had my pedal at about 60% again. Then I shut it off real quick and pulled the fuel pump fuse and cranked it to get some of the pressure off.

Once I thought it lost some pressure, I connected my fuel pressure tester. With the key-on-engine-off, I cycled the key a few times and no fuel pressure. Cranking saw no fuel pressure either. What gets me is it just started like 10min ago. So now it doesn't start at all.

I understand having a spare Main and CPS, I'll get them anyways.

325I

I'll check for spark ASAP, thanks.

[MavMan74]

I switched what I would guess Fuel Pump Relay and O2 Relay (only 2 four pin relays? unless main is a 4 pin as well). I also wiped off the CPS and there was a bit of crud around it. She started up fine. Switched the relays back and it still started fine. So I want to bet that this particular no start was the CPS that was nasty.

Fuel Pressure cranking and running was right under 40PSI and held it for several minutes after it was shut off. So fuel system is completely removed from the possible problems.

The ICV does buzz/vibrate. And it was just cleaned so It should be all good. TB was cleaned at the same time.

I'm going to rule the problem on a dirty CKPS. I'll order another one along with a few relays for insurance.

I'm also going to buy a few ignition items that the car vary much needs.

Thanks for all the help!:D

[e30Squid]

Chasing down an intermitting problem sucks.

They say 70% of all automotive problems are electronic....and the electronic components on our cars are over 20 years old at this point.

Hope your problem is fixed.

[quikveedb2]

You can test the cps with a multimeter, look in the bentley for the resistance specs. My money is on the main relay.

[MavMan74]

In the very end...it was the Main, I think. Relay at the far left if I remember correctly. After i cleaned the CPS it stalled on the way to work(right in the parking lot). I happened to have a relay in stock at work and put it in and its all good now. Starts fine in the morning and no longers stalls. So, yeah having a few 4 pin relays as backup is great advice.

Thanks for all the help! I'm new to German (and Imports) and it was a good learning experience.

[E30Rookie37]

Wow this is the exact problem I've been having with my car and had no idea what it could be and now I'm sure it's either the CPS or Main relay after reading this. My car started out with not starting but now it starts on a dime but at almost every stop light it will do a weird rev and then die. I hope it's as easy as one of these solutions.

[Dolmangar]

I've been working a similar issue. I'd been checking vacuum lines and the ICV (which I still think might be bad).

Car ('88 325is) runs fine most of the time, but in stop and go traffic, or pulling up to a light I'll get a hunting idle and unless I stay on the gas it will stall out. Sometimes it starts, other times it doesn't and has to wait for a few minutes to restart.

Probably worth replacing all the relays one by one and seeing if resolves. Looks like most of them aren't to expensive on Pelican, and several of them appear to be multipurpose.

Anyone have a good diagram or list of which relays should be tested/replaced first? I don't have my manual in front of me to look.

Thanks,
Mike

Wow this is the exact problem I've been having with my car and had no idea what it could be and now I'm sure it's either the CPS or Main relay after reading this. My car started out with not starting but now it starts on a dime but at almost every stop light it will do a weird rev and then die. I hope it's as easy as one of these solutions.

[Conki]

I have a very similar issue.
I checked fuel delivery rate and it was good, checked all fuses and relays and the CPS. For a few days it didn't want to start at all, and there was no spark. After leaving it sit for about a month I started it up, and surprisingly it idled seemingly well, but than started stuttering, and eventually it stalled. Every time I started it up after that, it did the same thing. Here is a video of it to show you guys what it does:



Even though the relays should be good I ordered a new fuel pump relay, an o2 sensor relay, and a main relay. They should arrive next week, I'll post if anything changed after replacing them. But for now, please let me know if you guys have anything in mind to check.

It really sucks that it starts up now, makes troubleshooting much harder..

[Conki]

Ok so yesterday I started it up again, and kept revving it for a little bit before I let it idle. I waited for about 5 minutes and it idled just fine without stuttering or stalling.

What do you guys think could cause this?

The reason why I parked the car months ago was that it didn't even want to start for 3 days. I didn't get spark. And now it starts right up.

I'm gonna clean the ICV and the MAF to see if that helps, but I'm open to other suggestions as well.